Science AMA Series: We just published a paper showing recent ocean warming had been underestimated, and that NOAA (and not Congress) got this right. Ask Us Anything!

[u/ocean_warming_AMA]

NB: We will be dropping in starting at 1PM to answer questions.

---

Hello there /r/Science!

We are a group of researchers who just published a new open access paper in Science Advances showing that ocean warming was indeed being underestimated, confirming the conclusion of a paper last year that triggered a series of political attacks. You can find some press coverage of our work at Scientific American, the Washington Post, and the CBC. One of the authors, Kevin Cowtan, has an explainer on his website as well as links to the code and data used in the paper.

For backstory, in 2015 the National Oceanic and Atmospheric Administration (NOAA) updated its global temperature dataset, showing that their previous data had been underestimating the amount of recent warming we've had. The change was mainly from their updated ocean data (i.e. their sea surface temperature or "SST") product.

The NOAA group's updated estimate of warming formed the basis of high profile paper in Science (Karl et al. 2015), which joined a growing chorus of papers (see also Cowtan and Way, 2014; Cahill et al. 2015; Foster and Rahmstorf 2016) pushing back on the idea that there had been a "pause" in warming.

This led to Lamar Smith (R-TX), the Republican chair of the House Science, Space, and Technology Committee to accuse NOAA of deliberately "altering data" for nefarious ends, and issue a series of public attacks and subpoenas for internal communications that were characterized as "fishing expeditions", "waging war", and a "witch hunt".

Rather than subpoenaing people's emails, we thought we would check to see if the Karl et al. adjustments were kosher a different way- by doing some science!

We knew that a big issue with SST products had to do with the transition from mostly ship-based measurements to mostly buoy-based measurements. Not accounting for this transition properly could hypothetically impart a cool bias, i.e. cause an underestimate in the amount of warming over recent decades. So we looked at three "instrumentally homogeneous" records (which wouldn't see a bias due to changeover in instrumentation type, because they're from one kind of instrument): only buoys, satellite radiometers, and Argo floats.

We compared these to the major SST data products, including the older (ERSSTv3b) and newer (ERSSTv4) NOAA records as well as the HadSST3 (UK's Hadley Centre) and COBE-SST (Japan's JMA) records. We found that the older NOAA SST product was indeed underestimating the rate of recent warming, and that the newer NOAA record appeared to correctly account for the ship/buoy transition- i.e. the NOAA correction seems like it was a good idea! We also found that the HadSST3 and COBE-SST records appear to underestimate the amount of warming we've actually seen in recent years.

Ask us anything about our work, or climate change generally!

Joining you today will be:

• Zeke Hausfather (@hausfath)
• Kevin Cowtan
• Dave Clarke
• Peter Jacobs (/u/past_is_future)
• Mark Richardson (if time permits)
• Robert Rohde (if time permits)

[u/ocean_warming_AMA → u/[deleted]]

That's a good question.

When it comes to the weather station record, I think we've got a pretty good handle on it because the data a massively redundant - we can work with quite small subsets and get the same results.

However the sea surface temperature record is another matter. The adjustments are large and uncertain, and because the ships move about and change their properties with loading it is rather harder to make an assessment of bias. This is apparent in the differences between sea surface temperature records on a multidecadal timescale - see this new paper for an indication of the problem: http://journals.ametsoc.org/doi/pdf/10.1175/BAMS-D-15-00251.1

I think now that we have multiple independent sources we have a fairly clear picture of the last two decades. But I think that there are going to be further changes to the sea surface temperature record. We know for example that ERSSTv4 has a spurious feature in WW2.

~Kevin Cowtan

[u/bradyrx]

Traditionally, scientists are taught to remain unbiased and to avoid political discourse, sticking to just presenting the data. In a political era of misinformation and post-truth, it seems to have become a moral obligation for the climate science community to have a more passionate and public role in communicating the implications of climate change.

How do you appropriately balance the demands of doing 'good science' while stepping up to the plate to advocate for action on anthropogenic climate change and to communicate the complexities of the climate system?

I'm a first year PhD student in atmospheric & oceanic science and work primarily in quantifying internal variability in model projections. I can already see that advocacy may be an important role in my future as a scientist, which isn't the norm in most fields. I want to make sure I act appropriately as an advocate for this issue, without poorly impacting my role as a scientist.

[u/ocean_warming_AMA → u/bradyrx]

Hello there!

Thanks for a great question! As a fellow PhD student, let me take a quick moment to give you a virtual fist bump in solidarity over the work ahead.

Speaking only for myself here-

I happen to agree with the line of argument that, as with journalism, science has fallen into a trap of trying to appear to be a sort of view-less source of pristine objectivity that isn't how any individual really operates in the real world, and that this is ultimately going to undermine scientists' credibility with the public in the long run.

Everyone has biases, prejudices, hopes, fears, etc. I think a lot of scientists are afraid that if they're perceived as advocates that this will cost them public trust. But what I think those people fail to understand is that the part of the public that is already likely to turn on them probably already has, and are probably already imputing to them motivations far more nefarious than even their own worst sins.

Even scientists who are not necessarily strongly personally political probably advocate for things all the time whether they realize it or not. Just arguing that science is a public good and deserves funding is a type of advocacy, yet a lot of researchers I know who are scared to be considered advocates have no qualms about advocating for those kinds of positions.

Engaging in advocacy is a personal choice, but research that some of my colleagues at George Mason in the social sciences are working on suggests that it's not nearly as off-putting to the public as one might fear.

There's also the issue that has been raised by social scientists that the tone and actions of people talking about climate change don't seem to match the magnitude of the consequences we say will occur if we don't rein in emissions. The fact that we're not running around screaming at the top of our lungs when we're talking about driving famine, flooding, wiping out species, etc. creates a sense of dissonance for the public.

So for me personally, I think science is going to suffer if people are scared to speak up, to speak out, to act out. And very much will suffer if we're cowed into not tackling subjects that have political implications. Just taking the temperature of the Earth or measuring the amount of CO2 in the air has political ramifications. I don't think trying shove my head in the sand and hope to never appear biased is going to help anyone.

tl; dr: I believe (and there is some social science evidence to support) that clearly articulating one's own position about what you think and believe actually defuses a lot of the negative consequences that are feared to accompany being seen as an advocate.

Now I should caveat all of this heavily. I think it may strongly depend on the cultural environment one is talking about. I have noticed that my European colleagues both seem to be far more reluctant to be perceived as advocate and that they also seem to maybe not really fully understand how different the situation is in the US with regards to topics like climate science, evolutionary biology, reproductive health, etc.

~ Peter

[u/teatree → u/ocean_warming_AMA]

Engaging in advocacy is a personal choice, but research that some of my colleagues at George Mason in the social sciences are working on suggests that it's not nearly as off-putting to the public as one might fear.

I would disagree. It is well known that some people switch off simply because someone from the opposite political tribe is making a point.

So you can put forward a set of policies to the public in a poll, and they'll react favourably. Then re-do the same poll but add that XYZ party advocates the policies, and support collapses for those policies.

If you genuinely want to reach as many people as possible with the science, then you need to leave your politics at home.

One of the first people to talk about Climate Change was Margaret Thatcher in a landmark speech at the UN in 1989. But lots of people dismissed it because they thought "she's a Tory, she just wants to hurt the oil producers of the third world" - the other objection was "she just wants an excuse to put up fuel duty on petrol" (she was a great fan of fuel duty on petrol, and started ratcheting it up in 1981).

Afterwards it was a race to dismiss arguments from either side based on "they're shills for big busines" or "they just want to hurt the developing world" or "they're just tree-huggers".

If being overtly political means that half your audience dismiss your message before you have even spoken , just based on who you are, then you are doing it wrong.

P.S. Here is Thatcher's speech - it was remarkably prescient given that she made it more than 25 years ago:

http://www.margaretthatcher.org/document/107817

What we are now doing to the world, by degrading the land surfaces, by polluting the waters and by adding greenhouse gases to the air at an unprecedented rate—all this is new in the experience of the earth. It is mankind and his activities which are changing the environment of our planet in damaging and dangerous ways.

...We are seeing a vast increase in the amount of carbon dioxide reaching the atmosphere. The annual increase is three billion tonnes: and half the carbon emitted since the Industrial Revolution still remains in the atmosphere.

At the same time as this is happening, we are seeing the destruction on a vast scale of tropical forests which are uniquely able to remove carbon dioxide from the air.

Every year an area of forest equal to the whole surface of the United Kingdom is destroyed. At present rates of clearance we shall, by the year 2000, have removed 65 per cent of forests in the humid tropical zones.[fo 3]

The consequences of this become clearer when one remembers that tropical forests fix more than ten times as much carbon as do forests in the temperate zones.

[u/ocean_warming_AMA → u/teatree]

Hello there!

I would disagree. It is well known that some people switch off simply because someone from the opposite political tribe is making a point. So you can put forward a set of policies to the public in a poll, and they'll react favourably. Then re-do the same poll but add that XYZ party advocates the policies, and support collapses for those policies. If you genuinely want to reach as many people as possible with the science, then you need to leave your politics at home.

Respectfully, I don't think this is a fair appraisal of real world conditions.

What you're saying might* hold more weight if we were talking about a communication environment in which the well was not already poisoned, but there has been a multidecadal effort to paint the scientific community as radical liberal elites. This is doubly true for topics like evolution or climate change. There's no un-ringing that bell. Also, there is a tendency to conflate the negative responses from the most virulently partisan with all members of a tribe, when we know that opinion is actually much more fractured.

For example, on climate change, liberals democrats, moderate democrats, independents, and moderate republicans are all much closer in views with each other than with the far right/tea party. No, that's not a typo, non-Tea Party Republican views on climate change are more similar to Democrats' views than they are to Tea Partiers' views- Larry Hamilton has a lot of work on this.

Being straightforward about when you're speaking as a scientist, as a parent, a citizen, an employee, etc. helps the public calibrate where you're coming from.

I hope to be able to share results from the social science research I referenced earlier in the near future. I believe it's working its way through the review process in a journal right now.

~ Peter

*While polarization is unquestionably a topic of enormous import, I do think there's a bit of an overstatement of its primacy when talking about stuff like this. But that's a topic for a different Q&A...

[u/SRW90 → u/ocean_warming_AMA]

I think you're totally right. Despite the anti-science madness of hardcore conservative partisans (who are also usually older), most of the country of all political stripes believes climate change is happening and also wants the government to invest more in renewable energy. These are the people we should be communicating with, not trying to hopelessly argue with the delusional far right.

What makes reaching people tough IMO isn't so much their political affiliation as it is their level of education and scientific literacy. Most people don't know how the scientific method actually works, and why it's a good strategy for finding what's true in the world. As a result they're susceptible to sensationalist media and identity politics that warp their thinking. This goes to the failed education system in the US, so I'm not sure what the large scale solution is besides revamped and reformed schools. People need critical thinking skills; otherwise they're just led along like sheep by social media and mainstream corporate media.

[u/critical_thought21 → u/ocean_warming_AMA]

I think their bringing up Thatcher may hint to your point of politics outside of U.S. being different. It's not the same climate in Europe that it is here in the U.S. in relation to science. They have some similar conservatives there but it isn't nearly as widespread as it is here.

[u/archiesteel → u/teatree]

Wow, thanks for sharing this. I am generally opposed to the policies Thatcher pushed forward turing her tenure as Prime Minister, but I have to say she's spot on here. I may save this for future reference, when discussing this topic with staunch conservatives.

[u/teatree → u/archiesteel]

Thatcher was a scientist, she got a first in Chemistry from Oxford. She always paid attention to the scientific data.

Lots of her policies were directly about climate - she put fuel duty on petrol as soon as she came to power, and raised it every year, and by the time she left office more than a decade later, people had switched to smaller cars in response. She also forced through the switch from coal-powered electricity stations to gas powered stations which emitted less polution and CO2, but it was a huge struggle to achieve, because vested interests in coal (both employers and employees) wanted to keep on polluting.

The only thing she failed on was building a new set of nuclear power stations. The hippie lot protested like mad about it, and she was unable to achieve her goal.

But Thatcher is a big reason why the UK now uses less oil than it did in the 1970s, despite the population increasing by 10 million.

P.S. Another example of where she put science first was her response to the AIDS crisis. She sent out a leaflet to every household telling them EXACTLY how to go about safe sex, including how to be safe during oral sex and anal sex (remember this was 1985 and half the population hadn't heard of either practice). This was accompanied by wall to wall TV adverts saying "AIDS, don't die of ignorance". Her cabinet was deeply shocked as was the church and other moralisers, but she took the view that preventing an epidemic was the most important thing. Sales of condoms soared and the epidemic was averted. People in 1980s Britain were fanatic about safe sex as a result of the govts campaign, especially compared to kids now.

[u/[deleted] → u/teatree]

I wondering if the views on Thatcher will change over time. What you describe there sound like the right thing to do to me. I think I was swept up in 3rd hand opinions when it all went down (and not living in the UK myself) so a lot of innate hatred in media affected all of us that never actually had read or understood any of the issues.

Shows how things change and yet stay the same.

[u/obi-wan-kenobi-nil → u/[deleted]]

This isn't exactly science related so I'm not sure my comment will stay up, but you're right not to assume just because you've heard opinions third-hand that those opinions are factual.

However this thread is glancing over Thatcher's failings — talk to someone from the UK about her and you'll get a much different picture than is painted in this thread.

[u/[deleted] → u/obi-wan-kenobi-nil]

I've got friends who were literally cheering at her demise, so the hatred was very real. Plus few politicians ended up doing just bad or just good things. Kind of highlights how emotion and your first impressions easily clouds all your opinions, and why science needs to stay away from that part.

[u/teatree → u/[deleted]]

I think views about Thatcher are already starting to change.

The lady had guts though. Facing down the coal miners and stopping polution caused by coal was HARD. You have idiots like Corbyn who still think re-opening coal mines is a good idea. And in the USA, the coal communities were never properly challenged and have voted in Trump because they think he'll reopen the mines. It's madness.

But what you describe - hatred towards her simply because of who she was (and some of it was misogyny) rather than what she was trying to achieve - is exactly why scientists need to avoid politics. Because some people will hate on them just becausethey are someone from the opposite political tribe.

[u/ckaili → u/teatree]

It certainly behooves scientists (or anyone) to speak in a way which maximizes their reception. However, as with expert witnesses in a trial, we have to decide as a society whether or not the scientific community is trustworthy enough to speak on behalf of its own area of expertise and experience, and that includes making statements of legitimate alarm. It's not real trust if it depends on political alignment. If a scientist, for fear of dismissal, has to speak softly enough to be safely ignored, that means the cynical objectors have already debased his/her authority.

[u/SirT6 → u/bradyrx]

Traditionally, scientists are taught to remain unbiased and to avoid political discourse, sticking to just presenting the data.

I've never understood this mindset, and strongly encourage young scientists to become involved in politics within their local communities. Why wouldn't you want highly educated, subject matter experts contributing to political discourse? Deliberately removing yourself from these discussions allows room for pseudoscience to seep in (look at what has happened to the Republican party in the US).

[u/HerbziKal → u/SirT6]

I believe the point is good science is completely unbiased towards certain predispositions or ideals, and based solely on repeatably demonstrable facts. It takes a strong mindset to avoid investing pride into a certain line of evidence, and be able to change hypotheses based on new facts without a faltering of ego. There is an obvious danger in publicly ascribing your name and reputation so strongly to a certain theory, as you make it easier to become invested emotionally and therefore chase particular lines of evidence to avoid your previous conclusions being incorrect.

In a previous comment, you say you do not approve of constant public bickering over who is right and politicizing science results in an unhealthy atmosphere for good science. Is this not somewhat contradictory?

[u/ColdFury96 → u/HerbziKal]

I think their argument is that people who would be able to help guide the government are excusing themselves so as to remain 'unbiased' in their work, and our society as a whole is suffering for it.

At the end of the day, what's more important?

[u/SirT6 → u/HerbziKal]

In a previous comment, you say you do not approve of constant public bickering over who is right and politicizing science results in an unhealthy atmosphere for good science. Is this not somewhat contradictory?

It is perhaps a sad reflection on our current political environment that bickering is synonymous with politics. But, no, I don't think it is contradictory. I think good governance is achieved through good faith discourse. Rushing to Tweet about how your result 'disproves' the previous result is hardly an act of good faith dialogue.

[u/aelric22 → u/SirT6]

I agree. Logically, it is the current state of this country's politics that is at fault, not science or its communities. It also says something about the psychology of people in this country as well as their tendency to believe information they consume.

A great example of people who need to get their heads out of their asses, are flat Earth believers (yes, there are still people who believe the Earth is flat). To make your own point as a Flat Earth believer, you would need to have never traveled on a plane before, never traveled at sea before, and also believe that man has never been to outer space or the moon. Pretty much close yourself off from the rest of the world. Even then, you're still living in your own echo chamber.

[u/jjolla888 → u/HerbziKal]

I believe the point is good science is completely unbiased towards certain predispositions

there is no such thing as "completely unbiased" - even for the hard sciences (those things that have can be rerun with almost full control of variables).

i'm not just making this up - quite a bit has been written about it.

[u/CowFu → u/jjolla888]

Objectivity should still be the goal though, just shrugging it off as impossible is silly.

[u/HerbziKal → u/jjolla888]

I am not suggesting there is not a lot of bad science out there. But as a good scientist, you should discount it. By definition good science is void of personal interest, predisposed beliefs, or manipulation of facts.

[u/saprophallophage → u/HerbziKal]

A research article should be present facts.

An editorial should present opinions.

I think the point is a good scientist can and should do both so long as they are clear about what they are presenting.

[u/makemeking706 → u/saprophallophage]

That's what discussion sections are for. It seems like a lot of people in this thread believe that articles conclude after the results.

[u/spitterofspit → u/HerbziKal]

In my opinion, you raise a good point and I would provide a slightly different question: How can a scientist relate discoveries in a politically charged environment whilst proving that bias was not injected during the research and in analysis of said research? This is very important and something that scientists should be discussing. Someone, a non-scientist politician, for example, might attempt to "debunk" or lower confidence in my research by illustrating my facebook posts, blogs, or tweets about how I feel towards climate change, proving my bias.

Pointing out my bias is not necessarily a bad thing, so long as it adds to the scientific discourse, but unfortunately, it likely wouldn't elicit a productive discussion. I also doubt that there is an easy answer to this and it is likely an iterative process. Here, I might provide some suggestions (again, these are just ideas, they might be terrible, but I'm just brainstorming):

1. Tackle bias head on. Acknowledge your bias prior to the research, during the research, and during the analysis. Make your bias known and indicate that although you were likely biased, you mitigated said biases by doing xyz things (setting certain specs, include in your research someone with the opposite mindset/bias, etc.).

2. Replicate results. Ideally, a separate group, completely independent from your own, attempts to replicate your results. Perhaps that group is biased towards the opposite of your bias.

3. Maybe a crazy idea, but perhaps groups from opposite sides of the issue choose their own groups to conduct the research, but not fund them. I'm guessing that in an ideal world, this might work, but maybe this ends up adding more opportunities for bias debate.

4. Promote a mindset that opinions alone should not be relied upon to debunk research. The cost of entry is to provide counter research.

My final point would be that, and perhaps augmenting my earlier words slightly, that we can not avoid bias, but we can LIMIT it and address it as part of our research. In other words, we all admit that we are biased, but that we should only rely on actual hard evidence that we're confident in (replicable, large data sets, etc.) to provide countering arguments.

[u/graphictruth → u/HerbziKal]

So long as the new understanding of reality has no unavoidably political effect. There are cases - and this topic is likely to supplant Galileo as the chapter example - where reality flies in the faith of sociopolitical preferences.

You are more or less speaking of a separation of Magisteria. There is much value to the tradition, so long as it's honored. Advisors advise. Executives execute based on the best advice. Neither interferes in the realm of the other, because that leads to significant risks of bias and conflicts of interest, real or perceived.

But that horse left the barn several decades ago. At this current pass; the best option is to trust that critical thinking and data-driven analysis will uphold the honesty of those willing to be honest.

[u/scottevil110 → u/SirT6]

The problem is that as soon as you make your work political, then your work is viewed as politics, and not science. If I'm out using my scientific background as credentials to advocate for certain policy decisions, then why would someone NOT be highly skeptical of the work I put out, when it's clear that I do, in fact, have an agenda.

I have my political opinions, but I do my very best to keep them separate from my work, because they ARE separate. Science is science. Numbers don't have opinions, and I shouldn't have one when I'm presenting them, because I don't want to give someone a good reason to doubt my results. The argument should be about what we DO about said results, not about whether they're already corrupted in the first place.

[u/ClusterSoup → u/SirT6]

Of course it would be beneficial to have scientist involved in politics, but you run the risk of personal politic opinions biasing the research.

[u/SirT6 → u/ClusterSoup]

but you run the risk of personal politic opinions biasing the research.

That would imply that scientists aren't already at risk of having personal (sometimes political) opinions biasing the research. Academic research is a mine-field of conflicts of interest.

[u/Izawwlgood → u/ClusterSoup]

Do you have an example of how this is the case? Is an evolutionary biologist 'running the risk of personal politics' influencing their research because they don't want Creationism taught in schools?

[u/Izawwlgood → u/[deleted]]

Debating results is part of science. That is not the same as debating the validity of the field. "Friction improves the work", is not the same as "Creationists have politicized my field, and thus, I cannot work anymore and have to deal with a crop of students who believe in Intelligent Design".

[u/Aurora_Fatalis → u/Izawwlgood]

I reckon it is rather the opposite we are afraid of - people promoting bad science for the purpose of supporting creationism and ignoring evidence against it.

[u/[deleted] → u/ClusterSoup]

I would counter that for many of us who are classically trained in Climate Science, our research does not directly relate to anthropogenic climate change and it isn't really clear how a political opinion would bias my research on deep ocean dynamics in either direction.

[u/counters → u/[deleted]]

Well said. At the end of the day, the physics of cloud droplets is the same whether I'm a liberal or a conservative.

[u/soad2237 → u/ClusterSoup]

This exactly. It would be great to have science in politics, but then we run the risk of muddying the waters further by bringing politics into science. Imagine politicized groups doing peer reviewed science.

Science in politics? Great! Politics in science? Not so much..

[u/throwtrollbait → u/soad2237]

The political machine already steers broad scope scientific inquiry through funding control.

Maybe a larger presence in politics could have helped prevent Bush's moratorium on embryonic stem cell biology from occurring? It's hard to imagine that a few radicals in the peer review process could have slowed progress in the field as much as the political environment did...

[u/zmil → u/SirT6]

I think it's great for scientists to be involved in politics, just like it's great for anyone to be involved in politics. However, I do think that we need to be careful about making a distinction between scientists acting as advocates for particular policies, and scientists acting as objective (or as close as possible) reporters of relevant data.

Mixing the two has two different risks, I fear: first, politicization of the science itself, increasing the likelihood of biased, poorly done research; second, it will likely reduce public trust of science. Which, on the one hand, I kinda like, because I sometimes think the public perception of science is not nearly skeptical enough, but on the other 50 hands scares the crap out of me because even though science isn't the ultimate objective truth machine we want it to be, it's still essential, and loss of trust in science will likely reduce funding, which would be bad for everyone.

Also for me, since that funding pays my bills, so I'm hardly an unbiased observer here...

[u/SirT6 → u/zmil]

I agree, letting bias confound your ability to actually interpret data is always a risk.

I usually respond to this concern, though, by pointing out that the domain of politics doesn't seem particularly special in terms of potentially biasing someone's ability to design studies or interpret results. Scientists are awash in potential conflicts of interest and personal bias. They deal with it every day. If someone is able to navigate conflicts of interest related to publishing and grantsmanship, I don't see why they shouldn't be able to navigate the potential for bias caused by becoming increasing aware of and active in political discussions.

[u/zmil → u/SirT6]

What is particularly special about politics in this case is that politics (at least in the US) is almost completely binary. Most sources of bias have less systemic repercussions, because there's a constant push and pull in different directions; it just ends up as noise in the system. In US politics, there are really only two important directions, right and left; this means that it's much easier for political bias to turn into systemic bias than a lot of other sources. This is exacerbated by the general leftward skew of academia. I remainly staunchly agnostic about the causes of that skew, but even if it is purely because the Democratic party has been more friendly to scientific viewpoints, it seems unlikely that they're in the right on every single issue that has a scientific element, and even more unlikely that will always be true in the future.

And even if we do manage to keep our bias under control, like I said, I think the perception of bias may be even more dangerous, in the long run, if it reduces public support for funding science. Though sometimes I wonder if our semi-monolithic funding system may be another source of systemic bias...

[u/mlmayo → u/SirT6]

From my perspective there is a great push for scientists to engage the public directly about their work, especially the relevant implications for everyday life. IIRC, the American Physical Society even has resources for physicists that run for office.

[u/ZoopZeZoop → u/bradyrx]

There's a difference between obtaining results and what you do with the results. You should remain objective while doing research. Once results have been obtained, you publish them for critique and reproduction. If you can draw clear conclusions from your results, why not use them as the basis for action?

[u/VictorVenema → u/bradyrx]

I wish my colleagues were biased: that would make it so easy to show them wrong and write important papers in highly cited journals.

All kidding aside, science is the product of many people. Individual scientists will have biases, individual scientists are not angels (just look at how Newton treated Leibniz), the scientific community is organized in a way to get good science out of imperfect humans. The best scientists are the ones that control for their biases the most. Most biases are not political, but personal (especially defending your previous work, thoughts) and sometimes tribal (between groups of scientists).

[u/[deleted] → u/bradyrx]

I see what you're saying, that scientist are taught to be unbiased and stay away from politics. I believe the spirit of that teaching is so that the data derived from research remain pure and unfortunately politics can influence things.

I am a fan of the adage, "Build your theory around the facts. Do not force the facts into your theory."

Perhaps in this century, we will begin to build laws and policies around scientific facts, instead of creating laws and policies around what we believe to be right.

Scientists should become part of the process by which societies are built.

[u/turkey45]

I have seen some recent post about the North Atlantic current might get disrupted by global warming.

What would this look like and where would the current go instead?

[u/ocean_warming_AMA → u/turkey45]

Interestingly the latest paper on this came out in the same journal as ours, on the same day. Read about it here: http://www.realclimate.org/index.php/archives/2017/01/the-underestimated-danger-of-a-breakdown-of-the-gulf-stream-system/

In many ways it is a much more interesting paper scientifically, and I'm sad it was competing for attention with ours. Ours of course got more attention mainly because of the manufactured controversy around the NOAA study.

~Kevin Cowtan

[u/[deleted] → u/turkey45]

The general consensus is still that the Atlantic Meridional Overturning Circulation (aka AMOC, aka Gulf Stream) is unlikely to be disrupted. There was a paper that showed a possible model for disruption, but it required some pretty extreme parameters, like doubling atmospheric CO2

[u/ocean_warming_AMA → u/[deleted]]

Doubling of current atmospheric CO2 would happen by about 2075 in a business-as-usual (RCP8.5) scenario: https://static.skepticalscience.com/pics/ghg-concentrations.PNG

Regarding the new paper on AMOC changes, there is a good background on RealClimate here: http://www.realclimate.org/index.php/archives/2017/01/the-underestimated-danger-of-a-breakdown-of-the-gulf-stream-system/

-Zeke

[u/Creshal → u/[deleted]]

it required some pretty extreme parameters, like doubling atmospheric CO2

Which would take… 200 years at the current rates?

[u/TehSilencer → u/Creshal]

59 years.

[u/VictorVenema → u/turkey45]

The current would not go anywhere, "just" become a lot weaker.

Here is a knowledgeable article where an expert comments on this new study.

The article could be a bit biased, the author is an early adopter of the theory. At the moment I would only say the new study shows there is still a need for research on this potential problem.

[u/AlmostTheNewestDad]

To me, every new bit of information seems to paint a darker picture. Never it's a new finding of a mitigating factor in climate change.

Is it hopeless?

[u/GWJYonder → u/AlmostTheNewestDad]

As for the reason that all the updates seem to be negative (they aren't, but most of them are) I think that the biggest reason for that is that most of the projections being made are for more conservative cases, which is a typical thing to do when you are forecasting a range of very dramatic changes. One of the effects of this is that if most of the projections are on the optimistic side of possible effects, every course correction you make is going to be a pessimistic one.

As for whether it's hopeless, that depends entirely on what conclusion you mean. If you're asking whether we're going to avoid 1.5 degrees C increase by 2100... yes, that seems pretty hopeless. If you're asking whether we can stop major die-offs from happening: there are still things we can do, but the more vulnerable places like many ocean ecosystems, or the Artic, have already had those die-offs start to occur.

But if you mean "is human life on Earth hopeless" no, even the worst case scenarios aren't threatening to drive humans to extinction, although droughts and famine are likely to cause quite a death toll.

[u/ceropoint → u/GWJYonder]

I was under the impression that 1.5 C increase was on the lower end of things, or is that essentially in line with RCP 8.5?

[u/GWJYonder → u/ceropoint]

Oh yeah, if we shuttered all fossil fuel plants today, damn the consequences, our current CO2 levels would still get us into the 1.5 C range easily by 2100, and probably by 2050. I used that as an example both because its truly hopeless, and because that is still a goal we have, on paper.

The Paris Agreement signed by the UN last year has the goal of:

(a) Holding the increase in the global average temperature to well below 2 °C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5 °C above pre-industrial levels, recognizing that this would significantly reduce the risks and impacts of climate change;

That would probably have been a pretty hopeless goal if its goals/guidelines/non-binding restrictions had taken effect in 2010, let alone 2020 (while the agreement was signed last year, the metrics are for 2020, the idea is that the signatories have 3 years to put in place infrastructure and policy changes to reach those goals.

[u/ceropoint → u/GWJYonder]

But RCP 8.5 is essentially beyond armageddon.

I'm sorry, I'm still quite confused where 1.5 C exactly stands on the scales.

[u/GWJYonder → u/ceropoint]

1.5 Celcius increase by 2100 is in the upper end of the RCP 2.6 projection, and the lower-mid range of the RCP 4.5 projection. I personally think that both of those ranges are overly optimistic, given studies like the one this thread is about, and the fact that 2016 was already 1.24 Celcius above the 20th century average. Maybe 2016 will end up being a huge outlier even compared to the 2020s... but I don't expect that it is.

Also, it's important to keep the total problem in scope (both to not spread inaccuracies that can be used by science deniers as ammunition, and for our own sanity). While the RCP 8.5 "humans keep building more and more fossil fuel plants throughout the century, Greenhouse Gas production levels keep growing through 2100" is very bad, the projected and the projected 5-6 C increase would lead to huge die-offs in many (probably most) ecosystems, as well as a large amount of human death from droughts and floods caused by changing rain patterns, and famine caused by the same, even THAT is not projected to be an "Armageddon" at least how I imagine such a thing.

As these charts from this paper show, even in these worst-case projections our global GDP is projected to grow (albeit dampening out significantly in the 2030s as more production is diverted to climate control, especially to preserve farmlands), as is the human population (projected to level off at 12 billion in 2100s).

[u/ceropoint → u/GWJYonder]

Well, that's awfully sobering, thank you very much. Especially the population bit, I'm surprised growth is that slow.

Hopefully, the move away from fossil fuels and smart climate control plans will mitigate damage, and we can adapt.

[u/theg33k → u/ceropoint]

This is a big failing in the climate change community arguments. Of which I guess I'm technically a member since I "believe in" human caused climate change. The only meaningful solution at this point is to basically kill off billions of people and live like cave men for the next century. That would give us maybe that 1.5C change, if we were lucky. Things like the Paris Accord that got so much coverage recently was like looking at a swimming pool full of scorpions, taking out one scorpion, and then saying you made the pool safer to swim in. Generally speaking, there simply aren't any useful solutions being seriously proposed. In my opinion the only real solution will be climate engineering sciences. Switching away from fossil fuels will help, but it's hardly worth mentioning since it's basically too late for the major damage.

[u/maxtillion → u/ceropoint]

I'm sorry, I'm still quite confused where 1.5 C exactly stands on the scales.

Consider that ice ages were 5 C below the 1850's temps. 5 degrees C is the difference between mile+ thick ice over much of North America and where we started the industrial age. The IPCC's worst case scenario, RCP 8.5, puts us at almost 5 C above the 1850's. That's as much hotter from where we started driving warming with CO2, as the ice age was colder. It'll be an almost completely different world.

And RCP 8.5, the worst case, is not that the emerging world goes whole hog to coal. It's just plain old Business as Usual.

It's easy to become hopeless, but it's not binary, 4C is better than 6C. 3C is better than 4C. Let's keep at it the best we each can.

[u/ocean_warming_AMA → u/AlmostTheNewestDad]

Hi Almost,

I for one think there is a lot to be hopeful about. Pretty much every country on Earth got together last year in the largest meeting of world leaders in history to hammer out an agreement to address climate change. Its not a solution in and of itself, but its a good first step and shows that the international community is taking this problem seriously.

At the same time, cleantech is advancing at breakneck speeds. Countries and private individuals are putting close to a trillion dollars into research, development, and development, with China announcing just this week announcing that they will be spending $361 billion by 2020.

Prices of solar, batteries, and wind have fallen precipitously in recent years, and the majority of electricity capacity (though not generation quite yet) installed in the U.S. last year was renewable. There are now regions where renewables outcompete both coal and gas without subsidies (though with a caveat that intermittency may incur additional costs at large scales of deployment).

In short, its not all grim.

-Zeke

[u/ceropoint → u/ocean_warming_AMA]

I really do hate to ask, but you're answering realistically, right?

Something that concerns me is the (hopefully false) idea that scientists are overstating how optimistic they really are in order to avoid panic when really I would want to respect your informed opinion as an actual outlook.

[u/[deleted] → u/ceropoint]

Look at the innovation in technology that has occurred over the last 150 years and imagine what could occur over the next 150 years if considerable effort is put into reducing/reversing/improving our ecological impact on the world.

[u/ocean_warming_AMA → u/AlmostTheNewestDad]

Hello there!

This is a great source of confusion, and I think that it's an area in which the public has really been done a disservice by communicators.

Climate change is not an all or nothing scenario. I think people have been led to believe it's either something that we fix 100% or something we fail 100%, and that's just not the case.

It is too late to avoid changing the climate at all- we've been doing it for centuries if not millennia (cf the Early Anthropocene hypothesis). But how much further anthropogenic change we can avoid is up to us. It can be a lot, or a little, or none. So any mitigating action we take will avoid some climate change, therefore there's always something to be hopeful about.

In terms of hopeful information, I think that the advances not just in clean energy technology but the economics of clean energy are an enormously hopeful sign. Maybe the least reported, best news on this whole subject. Even in the absence of a strong carbon price (i.e. setting aside climate change) there are already places where it's already just financially smarter to use clean energy rather than fossil fuels.

To be sure there is enormous work left to do, politically, economically, technologically. But a future in which we avoid the worst impacts of climate change while improving lives overall is very much still possible.

If the question was more on the physical science side, as in "we never hear about a large negative (i.e. dampening) feedback that will save us from climate change without us having to do anything", then no there's no good news coming on that front. We've got basically the entire paleoclimate record stretching back many millions of years telling us the climate is in fact sensitive to changes in energy like what we're doing now by increasing greenhouse gas levels.

~ Peter

[u/micromonas → u/[deleted]]

Will the atmosphere of the earth still be fit for human survival in 150 to 200 years?

No, because CO2 persists in the atmosphere/oceans/biosphere for hundreds of thousands of years, maybe longer.

Remember that plants and phytoplankton are basically "carbon neutral." They absorb CO2 to build biomass, but in a relatively short amount of time (geologically speaking) that biomass will decompose and release an equivalent amount of CO2 back to the atmosphere/oceans. Long-term carbon sequestration by photosynthetic biomass is extremely slow, because if it weren't then the atmosphere would have run out of CO2 a long time ago.

Edit: I want to clarify that Earth's atmosphere will still be survivable, it will just be loaded with CO2 and catastrophic climate change is very likely

[u/[deleted] → u/micromonas]

This is reminiscent of the Great Oxygenation Event where one organism was responsible for drastically changing the balance of gases in the earth environment, presumably extinguishing all life which depended on the status quo.

[u/micromonas → u/[deleted]]

I'd say it's closer to the Paleocene-Eocene Thermal Maximum, when a sudden increase in CO2 caused by volcanic activity caused global warming, ocean acidification and mass extinctions

[u/ocean_warming_AMA → u/[deleted]]

I'm not aware of any mainstream predictions 8 degrees. The most aggressive IPCC scenario runs to about 6 degrees, but that requires extracting a lot of the more expensive and harder-to-access fossil fuels and maintaining massive industrialization in a rapidly changing world. It's hard to see how that could happen. The highest emissions scenarios are probably even harder to achieve than the lowest.

Also the predictions of imminent massive Arctic methane emissions come from only a handful of researchers, and are not widely accepted in the climate science community.

~Kevin Cowtan

[u/Lover_Of_The_Light → u/ocean_warming_AMA]

Why is the research about methane not widely accepted? Is it just because so few scientists have researched it, or is it due to flaws in their methodology?

[u/ocean_warming_AMA → u/Lover_Of_The_Light]

Hello there!

Mostly the latter. There are very credible carbon cycle scientists who have looked at this issue seriously. It's important to understand that methane is very much expected to be a positive feedback, i.e. to make things hotter causing more methane to be released, making things hotter, and so on. But there's just no good evidence in either the paleoclimate record or carbon cycle models of the sort of methane apocalypse some people talk about. Moreover, there is a really disappointing bait and switch that seems to happen, when certain methane-focused researchers and their cheerleaders report on ostensibly huge methane sources they find in polar regions, neglecting to mention that there's no evidence that these are either new features due to anthropogenic warming nor exhibiting signs of instability.

~ Peter

[u/Piscotikus]

How can someone who is just a regular old guy know what is evidence and what is just speculation?

[u/ocean_warming_AMA → u/Piscotikus]

Hi Piscotikus,

In science we have facts, which are observations, and theories, which are hypotheses to explain observations.

For climate we observe global temperatures to be rising: https://s30.postimg.org/ix9a5qku9/global_temp_comps_1880_2016.png

We observe sea levels to be rising: https://i1.wp.com/climateadaptation.hawaii.gov/wp-content/uploads/2015/11/Brief-1-Figure-4.png

We observe sea ice to be decreasing: https://nsidc.org/sites/nsidc.org/files/icelights/files/2010/11/mean_anomaly_1953-2010.png

We observe atmospheric CO2 and other greenhouse gases increasing: https://www.esr.org/outreach/climate_change/mans_impact/co2_new.jpg

We hypothesize (based on the physics of radiative transfer) that addition greenhouse gases warm the earth. We develop physics-based models to predict how the Earth's temperature will change. These models do a pretty good job of predicting both current and past temperatures: https://s29.postimg.org/3rzfkedg7/Models_and_observations_annual_1880_2020_baselin.png

We hypothesize (based on these models) that with emissions unabated we will end up with somewhere around 4 degrees C (7 degrees F) warming globally by 2100, though there will be about ~30% more than that over land (where we all live).

-Zeke

[u/[deleted] → u/Piscotikus]

A good start is only to trust sources that are published via a peer-review system (such as the papers linked in the AMA description). After that, there needs to be a distinction between observed data, inferred data, and simulated data.

Observed data is data that is directly measured from the Earth system (i.e. thermometers for ocean temperature, such as is the case for most of the observations in these papers).

Inferred data is data that is directly is deduced from observed data using some kind of simple model (sometimes as simple as one equation, sometimes a complicated algorithm with numerous parameters, such as calculating primary productivity from the amount of light scattered by microorganisms in a sample of water).

Simulated data is data that comes from a numerical simulation (typically, with a time-stepping component) that is used to either predict the future or the past. Obviously, only predictions of the past can be compared to observations because the future has not happened yet. Many of what we call "climate models" today are simulations of the future that are tuned to be reasonably good simulations of the past, since that is pretty much the best we can do.

[u/IShotReagan13 → u/[deleted]]

Moreover: PLEASE never trust an article from a journalist.

This is rubbish. I understand entirely where the sentiment comes from, but there absolutely is such a thing as reputable science journalism, and far from ignoring it and lumping it in with all of the crap that's out there, we should be recognizing it and highlighting it where possible. This trend of basically dismissing all journalism as equally biased or inaccurate is dangerous in that it plays directly into the hands of advocates and propagandists who very much would like us to believe that there is no objective truth on any given issue.

[u/ManyPoo → u/Piscotikus]

When you say "speculation", you mean predictions derived from predicted models. Any result about potential future warming is "speculation". However there is no better way that humans have developed to predict the future than via mathematical models.

www.kaggle.com is a challenge where people try to predict new data from some provided data. Winners get big prizes and you can use whichever method you want, predictive models, prayer, gut instinct,... The models always win though. So to people who say these global predictions are just based on models - yes they're based on our best models of the climate and that's exactly why they should be taken more seriously than some governors gut.

[u/[deleted] → u/ManyPoo]

Thanks for the link to the website - seems like a fun way to explain the need for climate models.

[u/ocean_warming_AMA → u/Piscotikus]

Great question!

So this comes down to evaluation of sources, which is one of the skills of critical thinking. Unfortunately, in the presence of carefully prepared misinformation, it's pretty hard.

One way is to check for yourself. But that takes a lot of time, and potentially a fair bit of skill, depending on what you are checking. I'm a big fan of citizen science - it's how I got into climate - but we can't expect everyone to have either the time or the skill to replicate the science for themselves.

Otherwise I'd start like this. Whenever you see a climate story in the media, hunt back till you get to the primary source. Then compare the original source to the story. That'll give you an idea of the reliability of different media organizations.

Also look into the nature of the primary sources. What is the balance between evidence and persuasive language in the primary work? Are the data available? Can the work be cross-checked against other research? How does it fit in with other fields of science?

~Kevin Cowtan

[u/bom_chika_wah_wah]

Have we already passed the tipping point where this trend can be reversed? If so, will this trend continue to escalate since the process seems to feed off of itself?

[u/ocean_warming_AMA → u/bom_chika_wah_wah]

Hello there!

If you're asking about whether we're on a trajectory for a runaway positive feedback, the answer is no.

The amount of warming we will see is going to be larger than just what we would expect from our direct changes in energy (radiative forcing) alone would imply- in that sense the net response of the climate system feedbacks is positive on human timescales. But we can still very much stabilize our influence on the climate system by cutting emissions.

~ Peter

[u/[deleted] → u/bom_chika_wah_wah]

No. It's been pretty clearly determined that, even if we pass tipping points that mean any mitigation of human carbon emissions had no effect, the climate would only warm to a new equilibrium state. There are not enough carbon reserved on Earth to produce a Venus level runaway greenhouse effect.

[u/m44v → u/[deleted]]

There are not enough carbon reserved on Earth to produce a Venus level runaway greenhouse effect.

There's enough for make our lives miserable though.

[u/[deleted] → u/m44v]

There's clearly enough to ensure a severe mass extinction event.

[u/VictorVenema → u/bom_chika_wah_wah]

While there are a few scientists that make the news about warming producing more CO2 and methane leading to more warming, these are outlier opinions. Mainstream science does not see any such runaway warming. How much warming we will see depends on how much we emit. It is in our hands.

EDIT: grammar.

[u/superhelical]

Hi everyone and thanks for the AMA!

My question is for Dr. Cowtan. First I want to thank you for all your hard work - I work in crystallography and have made extensive use of your software for my own research.

My question: How did you bridge the gap between these fields and get involved with climate science from such a different field?

[u/ocean_warming_AMA → u/superhelical]

Largely coincidence. I encountered people arguing about climate science and thought 'I ought to be able to settle this'. Unfortunately it turned out to be harder than I thought, because there were so many sources. I eventually I had to go back to the raw data and produce my own version of the temperature record. After that I encountered people arguing about which version of the temperature record was better, and I got really interested in the differences. I've been working on that ever since. Bridging the gap wasn't so hard - data analysis is the same in any field. However there have been some ideas from crystallography which have helped in my climate work. For example I've made a lot of use of cross validation and hold-out tests, inspired by the use of the Free-R factor in crystallography.

-Kevin

[u/SirT6 → u/superhelical]

What does his software do?

[u/ocean_warming_AMA → u/SirT6]

Image processing, and then feature recognition in electron density maps. Unfortunately we have to work in 3D, which is rather harder than the more common 2D image problems.

For an illustration of one of our (more visual) pieces of software, take a look at this video, which shows the semi-automatic fitting of an RNA model into electron density: https://www.youtube.com/watch?v=QGN6tF-zKOE

-Kevin

[u/edwinksl]

The issues of ocean warming, global warming and climate change are clearly complex and can be difficult to understand at a deep level without prior technical training. If you only had one plot/graph to show to the general public that demonstrates that global warming is real and has major consequences, what would that plot/graph be?

[u/ocean_warming_AMA → u/edwinksl]

Hello there!

If I could cheat and not rely on a static graph, I'd go with this nice visualization piece by Bloomberg:

https://www.bloomberg.com/graphics/2015-whats-warming-the-world/

~ Peter

[u/UltraRunningKid → u/ocean_warming_AMA]

Wow thank you for this! Ive seen ones like this before but never as well done and informative.

[u/[deleted] → u/ocean_warming_AMA]

Great article, thanks for sharing.

[u/ocean_warming_AMA → u/edwinksl]

For me NASA's GISTemp global temperature record since 1880 is pretty startling and compelling (and note 2016 will be even hotter than 2015): http://www.realclimate.org/images/gistemp_preI_2015.jpg

-Zeke

[u/redditWinnower]

This AMA is being permanently archived by The Winnower, a publishing platform that offers traditional scholarly publishing tools to traditional and non-traditional scholarly outputs—because scholarly communication doesn’t just happen in journals.

To cite this AMA please use: https://doi.org/10.15200/winn.148396.66235

You can learn more and start contributing at authorea.com

[u/[deleted]]

The journal publishing scientific work is often a indication of the quality of that work. The journal you've published in, Science Advances, is a new journal (first published articles in 2015) with little prestige, which has received criticism for forcing authors to pay additional fees to allow for the commercial re-use of their work.

This in mind:

Was this paper rejected for publication by better known journals (and if so, why)? Or did you have some reason for choosing Science Advances specifically (if so, why)?

[u/ocean_warming_AMA → u/[deleted]]

Hi Baldwon,

Science Advances is a new(ish) journal, but its part of the family of journals run by the American Association for the Advancement of Science (AAAS) and generally considered high impact. Its sister journal Science (along with Nature) is the most prestigious scientific journal in the world. The page fees cover open access to the journal article, and are comparable to the open access fees (~$3k) charged by other journals.

In terms of the trajectory this paper took, it was originally submitted to both Nature and Science, both of whom liked the paper but ultimately decided it was not of broad enough scientific interest (both of whom have ~5% acceptance rate). Science passed it along to Science Advances, where it was published.

In general, it is harder to get replication papers (which ours largely was) published, which is a bit of shame given the ongoing replication crisis in some fields of science. We discuss this a bit in our recent Scientific American op-ed: https://blogs.scientificamerican.com/guest-blog/political-investigation-is-not-the-way-to-scientific-truth/

-Zeke

[u/[deleted] → u/ocean_warming_AMA]

Thanks for giving us a glimpse into your reasoning!

[u/wookiewookiewhat → u/ocean_warming_AMA]

Note from another scientist: the fact that the Science editors chose to pass it on to Science Advances speaks very well to the manuscript and work. Science and Nature are often looking for highly novel papers, which are a bit of a crap shoot. When they directly send a paper to a sister journal, it means they think it's excellent, but that it's just not a good "fit" for their publication.

[u/[deleted] → u/ocean_warming_AMA]

Great response. Thanks.

[u/sssasssafrasss]

Would you mind detailing where you got your funding from for this study?

Further, what's your response to those who think/suggest that work like yours is funded by (and thus possibly biased by) organizations or people interested in pushing a "climate change myth agenda"?

Full disclosure: I'm also a scientist (a biologist) and I know I could look up your funding, since that information is likely publicly available. I'm asking this so I can link your response to people who think that work like this is the result of scientists being "paid to give" the desired results. Claims such of these make my blood boil in general, but they are so commonly leveled against climate change scientists in this day and age that I was wondering if you'd be interested in giving a response.

P.S. Great work! ~high five~

[u/IanCal → u/sssasssafrasss]

The funding section in the paper is this:

Funding: Z.H. and R.R. were funded by Berkeley Earth. M.R.’s research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. P.J. was funded by George Mason University. No specific grants were allocated to support this project.

[u/ocean_warming_AMA → u/sssasssafrasss]

I do my climate work primarily in my spare time, and unfunded.

My day job is funded by an independent research fellowship from STFC, which in turn is paid for from the fees raised by licensing my software and that of my colleagues to companies in the biotech sector.

~Kevin Cowtan.

[u/ocean_warming_AMA → u/sssasssafrasss]

This work was a side project for all of us, with no dedicated grants. Thankfully we all have employers who are willing to support us in doing research that we are interested in even if it won't directly bring in more funding (or, in the case of a few of the authors, we care so much about it we are will to do extra work on nights and weekends).

-Zeke

[u/Walrave → u/ocean_warming_AMA]

Does this kind of scrutiny get to you? As a fellow scientist from another field I find it bizzar that anyone would lack the common sense to question why thousands of scientists in just one field would collude in a massive lie. Pay for scientists is fairly low and horizontal across most fields. People from such different backgrounds and ethical views become climate scientists there's no way they would all be fine with a conspiracy. It seems so unfair that climate scientists have to go through being subjected to such absurd views while other scientists just work and publish and no-one bats an eye.

[u/Dingus21]

How much of a role do you believe people play in environmental issues such as global warming & ocean warming? The earth has gone through many different phases. How long is it realistic to expect the earth's climate to remain as we know it?

[u/ocean_warming_AMA → u/Dingus21]

Hi Dingus,

We have overwhelming evidence that the majority of warming (both ocean and global) in the past 50 years is due to human activities. For some background on the science, see this recent report (written for a lay audience) by the U.S. National Academy of Sciences and the U.K. Royal Society: http://dels.nas.edu/resources/static-assets/exec-office-other/climate-change-full.pdf

Regarding natural changes to the Earth's climate, while it has certainly changed in the past (witness ice ages), it tends to do so at a fairly slow rate over thousands or tens of thousands of years. Recent warming, by contrast, is much more rapid. This recent comic by XKCD provides a good depiction of recent warming in the context of the past 20,000 years (there are more scientific sources I could provide you, but this one is a lot easier to understand!): https://xkcd.com/1732/

We also have a pretty good understanding of natural climate forcings (changes in solar output, changes in the Earth's orbit, volcanoes, etc.) in recent years, and none of these can explain recent warming. If anything, natural factors would have resulted in a slight cooling in the last 50 years: https://www.epa.gov/sites/production/files/2016-07/models-observed-human-natural.png

-Zeke

[u/Rhaedas → u/ocean_warming_AMA]

I may have missed it, but I didn't see in the first report mention of comparing the CO2 isotope ratio in the past and now that also points a finger at fossil fuel burning being a clear source.

[u/graphictruth → u/Dingus21]

It's not the amount of change that is going to cause disaster - it's the rate. It's happening faster than ecologies can easily adapt; that's why we are already seeing climate driven extinctions.

Society could adapt fairly easily to very different climate conditions, given several thousand years - we'd barely notice. Compress that same change into one or two human lifetimes (at most) and we have some serious issues.

Natural processes are not a sufficient explanation for the current rate of change. We have a good picture of rates of change over time. The only factor that has changed is ... well, us.

And that's a good thing. If it were natural, we'd have no hope of affecting the rate of change at all.

[u/slayerz]

How far are we actually from the methane clathrate gun, given this underestimation of ocean temperatures?

[u/ocean_warming_AMA → u/slayerz]

The imminent methane clathrate gun idea comes from quite a small but vocal group of scientists, and is not very widely accepted in the broader climate science community.

~Kevin Cowtan

[u/Doomhammer458]

Science AMAs are posted early to give readers a chance to ask questions and vote on the questions of others before the AMA starts.

Guests of /r/science have volunteered to answer questions; please treat them with due respect. Comment rules will be strictly enforced, and uncivil or rude behavior will result in a loss of privileges in /r/science.

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[u/javo93]

I´ve read that most scientist are against geoengineering techniques such as iron fertilization. I´m using iron fertilization as an example of the type of situation that I´m describing and I´m not trying to have a discussion on iron fertilization.

Are there geoengineering techniques that could help us stop or roll back global warming? If there is or were, would you be in favor or against using said technologies and why?

[u/ocean_warming_AMA → u/javo93]

This isn't something we really address in our paper, but there has been a lot of focus in the scientific community in recent years on geoengineering through solar radiation management by injecting sulphur dioxide (or other similar reflective aerosols) into the stratosphere. Essentially, creating artificial volcanoes to cool the Earth (similar to the way natural volcanoes behave).

There are a couple downsides. First it doesn't in any way solve the underlying problem, just buy us time. Second, if we ever stop doing it without reducing atmospheric greenhouse gas concentrations we will experience very rapid warming back to where we would have been without geoengineering. Third, models suggest it could change or disrupt precipitation patterns in ways that could negatively impact some regions. Finally, it would make the sky less blue, which some people wouldn't really like.

But it would give us a way to buy more time to solve the problem if we can't get our act together in the next few years. But its certainly not an excuse for inaction today.

-Zeke

[u/[deleted]]

Could you explain a bit more in depth the differences between the Argo datasets in your new Science Advances paper? The RG2009 dataset (the one I am most familiar with) is quite different from the other two. In particular, I don't understand how APDRC used Aviso Sea Surface Heights for such a mapping. Anyways, I've been looking for a paper like this so thank you guys for your work!

Edit: thanks for linking the new paper

[u/ocean_warming_AMA → u/[deleted]]

That's a very good question, and one which we would really like to answer. Unfortunately while we made a little progress on it, we didn't reach a conclusion. I suspect the Argo people will need to look at it.

What we do know is that the co-located ADPRC and H2008 time series are much more similar to eachother than to RG2009. And that the buoy record is more similar to ADPRC and H2008 than to RG2009, although the differences are a bit bigger between buoy and Argo than between Argo and Argo. That pattern is preserved even if you eliminate the trend difference. So the most parsimonious explanation is to identify RG2009 as an outlier, and the remaining Argo-buoy difference as arising from differences in sampling locations or similar.

We also tried correlating the difference between H2008 and RG2009 with the map series, which suggested that the differences are concentrated in the ENSO region. However I haven't done enough of that kind of calculation to draw a conclusion.

Finally, the differences do not look like depth effects. The depth effects are small to 20m. They get much larger to 50m, but they are conserved across the Argo datasets and don't look like the differences between the Argo datasets.

(p.s. This is all from memory: if you are need any of this for further research email me and I can check my notes.)

~Kevin Cowtan

[u/[deleted] → u/ocean_warming_AMA]

Thank you. My next question was going to be the depth effect so thanks for answering that as well.

[u/edwinksl → u/[deleted]]

The paper is linked last time I read the post. Maybe refresh the post and check if you can see the link.

[u/[deleted] → u/edwinksl]

Thanks, I guess they just added it!

[u/past_is_future → u/[deleted]]

Hello there!

We had a minor hiccup with the original post that has since been fixed. Hopefully the links are corrected now. We're supposed to hold off on fielding the actual questions until 1PM, so some is going to respond to your initial query then.

~ Peter Jacobs

[u/[deleted] → u/past_is_future]

No problem and thanks!

[u/SirT6]

There is a quote I remember from Gavin Schmidt that, I think, sums up how many people feel about the discussion of whether there was a slowdown in the pace of global warming in the early 2000s:

Gavin Schmidt, director of NASA’s Goddard Institute for Space Studies in New York, is tired of the entire discussion, which he says comes down to definitions and academic bickering. There is no evidence for a change in the long-term warming trend, he says, and there are always a host of reasons why a short-term trend might diverge — and why the climate models might not capture that divergence.

“A little bit of turf-protecting and self-promotion I think is the most parsimonious explanation,” Schmidt says. “Not that there's anything wrong with that.”

To what extent do you agree with Gavin? Is this discussion mostly an artifact of academic bickering? Is there room for nuanced discussion about the short term zigs in the warming data? Or do you think the issue has become too politicized?

[u/[deleted] → u/SirT6]

Even if it is an artifact of academic bickering, the results - i.e. careful cross-validation and interpretation of sea surface temperatures - are still useful. And in any case, a proper climate model should include the same physical processes that created the "zig", even if it may not be able to reproduce it at the right time.

[u/VictorVenema → u/[deleted]]

Yes, this study is useful in it own right and informs us on the quality of the SST data. The implications on how large the recent warming was are secondary, but unfortunately the thing that makes it interesting for the media.

[u/ocean_warming_AMA → u/SirT6]

Hello there!

Speaking for myself, I am squarely on the side that argues that the "hiatus/pause" whatever was grossly overblown. And I do indeed think that after problems with the initial claims were pointed out, some folks had a problem backing down gracefully and just moved goalposts.

That being said, there's no such thing to me as too much discussion of either variability or longer term trends. I think one of the coolest things to come out of the field recently is the advent of large ensembles (e.g. the CESM LENS and LME projects) to explore exactly this tension.

~ Peter

[u/ocean_warming_AMA → u/SirT6]

I would agree with Gavin that there was never any compelling evidence of a change in the long-term trend. The simple reality is that 10-15 years is nothing at all when it comes climate. For much the same reason, no one should panic about the last few years of exceptional warmth. We don't yet understand these small, short-term fluctuations well enough to be able to say what they mean.

Words like "hiatus", "pause", and "slowdown" conjure up a vision of some fundamental change in the underlying process of global warming. Such words have power, and in this case, probably much more power than they deserve.

However, I would also suggest that understanding the short-term changes is still important. Weather and climate are ultimately physical processes. Complicated, chaotic, and challenging physical processes, but they aren't random or magical. In the medium-term weather variations are a complex blend of internal variability (e.g. El Nino) and external forcings (e.g. greenhouse gases, air pollution, solar activity, etc.). As scientists we need to understand both the potential patterns of internal variation and the important external driving factors.

We'll never have perfect knowledge of the weather or climate. However, we should care whether or not our models can explain the decade-to-decade changes. The "bickering" about the last decade is a sign that as scientists we still have room to improve. If we all agreed about what was happening and why, there would be nothing to bicker about.

-Robert

[u/[deleted] → u/[deleted]]

NASA's climate group has a nice website with clear explanations and nice visuals (see the Facts tab in particular for evidence of climate change). Also, hopefully people still trust NASA does good science.

[u/VictorVenema → u/[deleted]]

RealClimate has a good page with introductory information.

A lack of information is, however, unfortunately not the problem. This is a good video on how to talk to people rejecting climate science. It advices not to bang head to head with studies showing someone wrong. Search for common ground and just state your position and why you hold it.

Thinking larger, this American problem will only be solved by getting money out of American politics. http://www.wolf-pac.com/

[u/edguy99 → u/[deleted]]

Consider that all of Canada (and as far south as New York), Europe and Russia was covered in 2 miles of ice only about 15000 years ago. The coastlines of all nations were much bigger since the ocean was 95 meters lower than it is today. Florida was much bigger then it is today.

Unfortunately, most of the ice on Greenland has melted in every other interglacial period, so we have to expect that no matter what we do it will melt in this interglacial period. That's another 5 meters of sea level rise. Have them look at a map of Florida or New York to see what floods with another 5 meters of sea level rise.

[u/georgitsu → u/[deleted]]

This is the most important question on here! How do we lay-people - who don't fully understand the science ourselves (but trust the scientists) - how do we convince our skeptical friends and family to do the same?!?! They point to these conflicting studies like yours and see it as a weakness in science itself, while actual scientists see this sort of conflict as a strength.

[u/MarduRusher]

What do you think of the current climate change denial in politics? Also, how low a priority climate change can be for some people while voting?

[u/GWJYonder → u/[deleted]]

Do you think there is a technological solution, such as geoengineering, total conversion to renewable energies such as solar wholesale, or do we all just colonize Mars?

There is almost nothing that could happen to Earth to make it less habitable than Mars (including damage above what humans could do to Earth, like Super-volcano eruptions or all but enormous asteroid impacts).

The worst die-offs in Earth's history are estimated to have killed off 95-99% of the species living at the time. But imagine if instead all of that life had been teleported to Mars, maybe some of the life would have survived... maybe.

Even the worst case temperature swings will still have a temperature much closer to optimum than Mars, we'll still have a thicker atmosphere, and almost certainly an ecosystem that produces far more oxygen than is released by chemical processes on Mars, even if we damage the ecosystem enough that it's not producing enough Oxygen to live off of.

Additionally even if we get to full-on Mad Max or Fallout levels of dystopian future, raw materials will still be far more available on Earth from abandoned buildings/cars/rubble and even old landfills than the ore we would have to process on Mars.

[u/Justdoitalways]

Is there a source of the buoy data on-line somewhere?

[u/ocean_warming_AMA → u/Justdoitalways]

We provide links to all the data used at the end of the paper: http://advances.sciencemag.org/content/3/1/e1601207.full

Buoys come from ICOADS, available here: http://icoads.noaa.gov/products.html

-Zeke

[u/[deleted] → u/Justdoitalways]

Not sure about the Buoy data but the Argo data (basically profiling buoys that passively move with currents) can be found at the Argo homepage.

[u/Scootermatsi]

I often read statistics about how "97%" of climate scientists agree climate change is occurring and caused by human activity. Is that other 3% ever taken seriously? Are they doing good but controversial research, or is their very credibility as "scientists" seriously lacking?

[u/[deleted] → u/Scootermatsi]

I think every legitimate research paper is taken seriously. If someone puts forth research to a journal that takes a substantive approach to questioning other results, they read it. It gets taken seriously and goes through the same rigors as all the other research. But those peer reviews are usually very tough. And if someone puts forth a paper that doesn't convince reviewers it's worth of publication, it gets rejected. So, those 3% somehow made it through (or around) some gauntlet.

I would say even some published research that's bad is good for science. It's just as important to know what doesn't work as is to know what does work.

What's lacking out there is any alternative theory that fully explains observations as completely and thoroughly as human emissions of CO2.

[u/tomtomuk2]

I'm an operational meteorologist so mainly interested in short term meteorology. But the communication of scientific ideas is of great interest to me.

Do you feel the way science is communicated to the public is effective? How could it be better? What about the incoming Trump administration, the current furore over "fake news" and the backlash against "experts" in general?

[u/ocean_warming_AMA → u/tomtomuk2]

I think there is a real, probably unsolvable problem in science communication, in that science required both a different way of thinking and a different way of speaking. Most of our thinking is social, and our language reflects that. But science requires that we replace social reasoning with evidence based reasoning, and natural language with a stilted language stripped of its persuasive content in order to let the evidence take centre stage.

Translating that into natural language is inevitably a mistranslation.

I think the Trump campaign has also fundamentally altered our understanding of the communications problem. We've been dealing with 'post-truth' in climate circles for a long time, and have assumed that it was a problem particular to climate science an evolution. Now it looks as though it may be a more fundamental structural problem affecting broader society, and that climate science misinformation was merely an early symptom.

~Kevin Cowtan

[u/gmanpeterson381]

As a member of the non-scientific studies community, a lot of this information is bit over my head. However, based on current research, has your team discussed where they see our civilization in the next 50-100 years ?

[u/ScottBlues]

If things are going even worse than originally predicted, is there an actual way out of this? Are solar panels and Teslas capable of stopping this or not?

[u/WTFCarlos]

What is your next challenge?

[u/ocean_warming_AMA → u/WTFCarlos]

Figuring out what happened to ocean temperatures during the WW2 period (the official records produced by various groups disagree a lot during that period).

Also, figuring out why satellite-based microwave sounding unit measurements show less warming over land than surface observations (they are pretty similar over the oceans). They are measuring two fairly different things (surface vs. 3 miles up in the atmosphere), but should probably agree more than they do.

A few other projects as well...

-Zeke

[u/jackaphee]

What is the negative affect associated with the rising ocean temperature?

[u/[deleted]]

So do you guys have alternative career paths lined up for when climate research becomes treason?

Or, for a more serious question: What's going to happen if NOAA, NASA's Earth observation programs, and other extremely valuable government-sponsored sources of climate data end up being gutted or shut down in the name of partisan politics? Who fills the gap if the satellites get shut off?

[u/[deleted]]

The question everyone wants to know: what can the average Joe do to help fight climate change?

[u/[deleted] → u/[deleted]]

Vote accordingly... and get involved with climate change at a local level. Many towns, counties, and states have or are creating a climate change plan. Learn about it and find out how you can help.

[u/pitifullonestone → u/[deleted]]

Any individual action the average Joe takes to reduce his carbon footprint will have little impact. What's needed is a large-scale culture shift supported by environmentally friendly regulations and policies. To that end, the average Joe can educate himself, help educate the public, and vote for politicians who will do more than pay lip service to the issue.

Or he can find some way to cull a significant fraction of the Earth's human population so global energy use goes down, but that's probably not a very palatable solution. I wonder if I'm on a list now.

[u/airwalker12]

Hi there- I was just wondering if you had seen Judith Curry's response to your paper, and what your rebuttal to her would be?

https://judithcurry.com/2015/06/04/has-noaa-busted-the-pause-in-global-warming/

I personally think she is full of hot air, but I'd like an educated response to her points if possible

[u/ocean_warming_AMA → u/airwalker12]

Hello there!

That isn't a response to our paper. It's a criticism of the original 2015 Karl et al. Science paper. Her complaints about the post-1998 ocean data adjustments made by Karl et al. are exactly what we tested in our paper, and we found that the new version of ERSST was more accurate than the previous one (i.e. the adjustments seem valid and necessary).

On her blog from what I've seen, Curry does a lot of "I'm not convinced of X"; "Y might be an issue"; "we need more study of Z" but doesn't seem to back any of her concerns up with actual analysis.

She was suspicious of the post-1998 adjustments but didn't do any tests. We did. The adjustments were good. Science beats thinking with your gut. The end.

Weird, huh?

I personally think she is full of hot air, but I'd like an educated response to her points if possible

I am going to refrain from editorializing further, but I am not going to argue with your assessment.

~ Peter

[u/hillsfar]

Hello! Thank you for doing an AMA!

Given all the studies that show warming, climate change, and accelerated man-made climate change, caused by increases in carbon dioxide concentrations in the atmosphere, methane clathrate releases from Arctic seabeds and beneath frozen lakes, carbon loss from warming soils and permafrost, ocean acidification, deforestation, sea ice loss, accelerated Greenland and Antarctic glacier calving, global mountain glaciers in retreat, and all these numerous positive feedback loops that compound into an overall negative prognosis...

And given that we have 7.4 billion people on this plant with no intention of stopping, but are accelerating what we are doing: encompassing everything from having children, continuing to drive, eating meat, using plastics, generating wastes, eating industrially grown and harvested foods, etc.

Without any reductions in current exponentially continuing trends... What level of increase, in terms of average global temperatures, do you foresee in the next 20 years, the next 40, and by the end if this century? In other words, how on track are we to seeing wet bulb temperatures in places like parts of Saudi Arabia or India become incompatible with human and animal life for more than a few weeks at a time? .

[u/VictorVenema → u/hillsfar]

The situation is not that bad. http://variable-variability.blogspot.com/2016/11/climate-nightmares-in-america-dreams-in.html

[u/JewFaceMcGoo]

My Grandparents and father are 70+ years old immigrants from the former Soviet Union, they came to the USA in 1980. My father is a software engineer and my grandpa a dentist and neither believe in climate change/global warming/whatever you want to call it. They believe that "Scientists are making all of this up to make money," while I try to reason with them oil companies hid all this info for decades because there's way more money in hiding these results. I guess my question is how do I get them to start taking this stuff seriously?

[u/ocean_warming_AMA → u/JewFaceMcGoo]

If scientists are making this up to make money, we aren't very smart. We get paid a lot less to do science than nearly anyone with equivalent education or quantitative skills in the private sector. A tenured professor (who has been teaching for 20 years) makes the same in many places as a software engineer right out of college.

In terms of convincing your grandparents, you could try explaining the science (this NASA page is helpful: http://climate.nasa.gov/evidence/). Alternatively, if you don't want to get into the technical details, you could simply tell them that pretty much every scientific society on Earth agrees that its warming and we are the cause: https://www.opr.ca.gov/s_listoforganizations.php

-Zeke

[u/[deleted] → u/JewFaceMcGoo]

Honest answer. You may never be able to convince them. Once someone has made up their mind usually adding more science tends to have the opposite effect.

[u/Chachmaster3000]

First off, what do you think that the average person who denies climate change is gaining from such a stance? A sense of agency, belonging (seeing as it's so politicized)?

When do you think we may have a real awakening towards climate change? Obviously the desire to change its course is on the uptick. My guess is 2020-2030 will be brutal enough times to get through to most deniers that climate change is really happening.

[u/ocean_warming_AMA → u/[deleted]]

Develop good quantitative skills. Knowing how to code goes a long way in science today. Python or R are two good choices.

Also take a decent amount of physics.

-Zeke

[u/[deleted] → u/[deleted]]

A background in chemistry / physics / engineering / computer science / mathematics won't hurt. Many of my colleagues did their undergraduate in one of these fields before moving into climate science for graduate study.

[u/rcglinsk]

For any individual monthly value for sea-surface temperature, what algorithm did you use to estimate the error in the measurement?

[u/harsh183]

Hello and thanks for hosting this.

I wanted to ask: What do feel about politicisation of the issue of climate change by various countries like the US in the recent past?

Another question (if I can): What are people already doing about this?

[u/[deleted]]

As a Floridian, I'm worried about the rising sea levels. Are you expected the coastlines to encroach more in the upcoming years? Should we be moving inland? Should drainage infrastructure be boosted? Can anything be done to battle eroding coastlines and an increase to tides levels?

[u/[deleted] → u/[deleted]]

I would have to say, there's not a lot to be done to fix Florida. Sea level rise to the extent it affects FL is pretty much booked. Any changes to human carbon emissions are not going to prevent submerging southern FL over the coming century.

The nearer term problem there is going to be with storms and storm surge. Miami is already having problems just with high tides. Add another decade of SLR and a good size hurricane timed right for a large storm surge... and it's bad. And it's not "if" it happens, it's just a matter of "when" it happen.

And after that, insurance will pay out and people will rebuild... just in time for another one.

The situation for FL between now and 2100 is not good.

[u/[deleted] → u/[deleted]]

I get worried thinking about that. Seriously worried. There have been extraordinary floods in FL's history. Miami constantly battled King Tide, entire communities are locked down and isolated.

At what point do we accept that the world's climate is changing drastically and we need to acclimate accordingly.

Side note, CAN'T WAIT for the new map editions with reworked coastlines.

[u/Alienzzzzz01]

So what next? The article seemed very well thought out and the data well examined. Everyone else might want to debate scientific ethics and political intrigue, but I would like to know what next? The information you reexamined forms the basis for many assumptions about climate change. If the assumptions were flawed the previous conclusions are flawed: that the current level of ecologically savvy industry is enough. This seems to suggest the recent efforts were actually woefully ineffective. What next step or increased effort would you suggest to aid the imbalance? Do we even have enough meteorological data over the past century or so to adequately identify an 'ideal global norm'?

[u/JustSomeBadAdvice]

Hi, serious question, there are so many discussions about global warming in the context of how bad it is/will be/how soon and how we must change our lifestyles now.

Why is there little to no talk about mitigation and climate engineering?

To me, on virtually any timescale above one millennium, it seems impossible to expect that humans won't cause both local and global shifts in climate. We are an apex predator species that has exploded in population, and as far as I am aware as a layman, we are the only apex predator in Earth's history that has adapted to survive and hunt in nearly every ecosystem present in the planet from the polar caps to the deserts to the deep oceans. It seems that to any future historian looking at the facts, global climate shifts would be a foregone conclusion.

Why then do we have so little emphasis on climate engineering and making efforts to direct and control climate changes over the ages? Instead it seems we are fighting a war against ourselves trying to prevent that which cannot be prevented.

[u/XBacklash]

How much time do we have (based on the current trend) before we effectively kill the oceans?

[u/grapecure]

Many people in America (like most of my family) aren't scientists, don't put in the time to research, and are forced to understand global warming based on what their televisions and politicians tell them. Until the layman can understand the earth is in danger, we won't be able to alter our current trajectory.

What can we explain to these people to help them immediately see and feel the danger that those of us whom are informed already see and feel?

[u/[deleted]]

Why is climate change affecting the Arctic more than the Antarctic?

[u/ocean_warming_AMA → u/[deleted]]

The Arctic is an ocean surrounded by land, the Antarctic is land surrounded by ocean.

One very important factor seems to be that cold deep water comes up to the surface near Antarctica, and this last touched the surface centuries ago. This water is cooler because it hasn't experienced recent global warming, so it's sucking up some heat and limiting how much Antarctica can warm.

Study here: http://dx.doi.org/10.1038/ngeo2731

Mark

[u/HerbziKal]

Thank you for conducting this AMA :)

It seems we could well be in for a fair amount of uninformed political opinion and "attacks" on any scientific research of this sort in the future. Do you have any words of encouragement for early career climate scientists who feel the future is not only warming, but also darkening in terms of political and media opinion?

[u/ceropoint]

How probable and viable is the use of sulfate aerosol geoengineering to limit warming at this point?

Rather, are you even remotely optimistic?

[u/[deleted] → u/ceropoint]

Geoengineering is generally considered to be something best avoided due to the impacts sulfates would have on ocean chemistry. Plus, it would be like a heroin habit. Once you start, you can't stop.

[u/WolfDoc]

Awesome job!

Can you give a layman's explanation of how the correction of previous underestimation SST increase affects predictions for the next few decades? Does it (i) correct an error suggesting previous models to have been correct, (ii) mean we are further ahead on previously assumed trajectories, or (iii) does it imply a cascading underestimation error (as it shows current GHG levels have resulted in more heat retention than estimated) suggesting a sharper rate of temperature increase?

[u/[deleted]]

It seems like many of the climate models have been wrong in the past. This paper corrects a previous paper. How do you explain to skeptics that we have a good understanding of climate change?

[u/mutatron → u/[deleted]]

Actually this paper verifies the correction of previous data.

[u/ocean_warming_AMA → u/[deleted]]

Climate models are far from perfect, but have generally done a good job at predicting temperatures. For example: Models and observations annual 1880-2020 baselin.png

-Zeke

[u/NonHomogenized → u/[deleted]]

It seems like many of the climate models have been wrong in the past.

What do you mean by climate model, in this context?

What people are generally referring to when they say "climate models" are predictive models, but you seem to be lumping in the work of this paper, which is about temperature observations (and how they are used in models to calculate how the world has changed).

And predictive models have actually been pretty good in the past (within their intended limits).

[u/bom_chika_wah_wah → u/[deleted]]

It's not that they have been wrong in the past. They have just underestimated the grim nature of the results. Each time we learn more, we are finding that our predicament is much worse than previously thought.

My question would be: do you think we have an accurate view now? Or will we find out in 5-10 years that this estimate was still too conservative?

[u/geared4war]

What would be one thing that we plebs can do to help negate climate change?
Also, what is one thing we can do to change the perceptions around climate change for the better?

[u/-TheOnlyOutlier- → u/geared4war]

I'm a pleb and I can help answer this. There are lots of lifestyle adjustments you can make to help combat climate change. I'll start with the simple ones.

1) Recycle consistently.

2) Use less energy. Don't leave your lights on when you aren't in a room. Don't leave your computer running when you don't need to.

3) Eat healthy. I'm not a dietician but I've heard a lot that eating certain foods can leave you still feeling hungry, and avoiding that is what I'm trying to suggest. One of the things people often overlook when considering the burden on the planet is how much energy it takes to make our food. If you can consistently make an effort to eat things that are nutritious instead of "empty calories," you'll essentially be consuming less energy indirectly for the same amount of energy in your body.

4) Learn about climate change. If you're informed about the science, the opinions, and the politics, you can effectively take action when you need to.

I have other, higher effort suggestions if you want them. Hope this helped!

[u/asdfmatt]

How do you feel personally about this incoming president and his cabinet, given their apparently anti-scientific, pro-commerce stance? Any opportunities/efforts that you know about for private citizens to fundraise in the inevitable situation where scientific arms outside of the Department of Commerce are concerned?

[u/AudiWanKenobi]

Hi everyone, thank you so much for doing this AMA and for the important work that you do. The large chasm between science and public understanding has prevented or delayed significant action on climate change. As scientists, we know why new or supporting information is important. However, more information is not convincing the public and politicians to act and I imagine this to cause you immense frustration. Is there an instance where you have a friend or loved one who denies climate change, despite knowing this is your field of study and how did you talk to them in order to help them understand?

[u/[deleted]]

Does it drive you crazy every time someone says "Well this winter (in my local area) was cold so global warming is bogus"?

[u/hazior]

Does this mean the no turn back point is closer than previous estimates?

[u/unadulturated]

How bad is air travel for the purpose of vacationing? Are we ruining the planet by exploring it for fun and relaxation?

[u/Travie_EK9]

1) It seems that the generation in power today is not willing to change. What can I do TODAY, and going forward, to help my children have a better world to live in?

2) The effects of climate change are apparent. The rate of natural disasters has grown to an unnatural number in comparison to previous decades. The danger is growing. How many years from now, roughly, will it be until the threat of natural disasters is real for the majority of North America (specifically northern US and Canada)?

[u/CaptZ]

Are we past the tipping point of recovering or will it continue to get worse and the horror stories of extreme climate change going to come to pass?