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So What Happened with ClimateGate?

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Remember back in December, when the news was buzzing each day about the stolen emails from top climate researchers? They were described as “the final nail in the coffin of anthropogenic global warming”, or worse. Apparently, the scientists had written things that severely compromised the underpinnings for the idea that human activity was causing the Earth to warm. We could now all stop worrying and forget about cap-and-trade.

But that wasn’t the end of the story. There were no less than four independent investigations into the contents of these emails – conducted by scientists, universities, and governments, not general reporters rushing off a story about an area of science with which they were unfamiliar, and trying to make it sound interesting and controversial in the process.

So what did these investigations find? Is the Earth still warming? Are humans still responsible? Can we trust the scientific process any more, or should we throw peer-review out the window and practice Blog Science instead?

Actually, all four of the investigations concluded that absolutely no science was compromised by the contents of the emails. The CRU scientists weren’t as good as they should have been about making data easily accessible to others, but that was the only real criticism. These scientists are not frauds, although they are accused of it on a daily basis.

Pennsylvania State University, over a series of two reports, investigated the actions of their employee, Dr. Michael Mann, who is arguably at the top of the field of paleoclimatology. They found that, contrary to most accounts in the mainstream media, he did not hide or manipulate any data to exaggerate global warming, delete any emails that might seem suspicious and be subject to Freedom of Information requests, or unjustly suppress skeptical papers from publication. After a second investigation, following up on the catch-all accusation of “seriously deviating from accepted practices within the academic community”, Penn State exonerated Mann. They criticized him for occasionally sharing unpublished manuscripts with his colleagues without first obtaining the express permission of the authors, but besides that minor (and somewhat unrelated) reprimand, they found absolutely nothing wrong.

The British House of Commons investigated the actions of CRU director Phil Jones, and came to a similar conclusion. They found that his “actions were in line with common practice in the climate science community”, that he was “not part of a systematic attempt to mislead” or “subvert the peer review process”, and that “the focus on CRU….has been largely misplaced”. They criticized CRU’s lack of openness with their data, but said that the responsibility should lie with the University of East Anglia, which CRU is a part of. So these scientists should really catch up to the climate research team at NASA, for example, which publishes all of their raw data, methodologies, and computer codes online, with impeccable archives.

The University of East Anglia conducted their own investigation into the actions of CRU as a whole. They found “no hint of tailoring results to a particular agenda”, and asserted that “allegations of deliberate misrepresentation and unjustified selection of data are not valid”. They also explored the lack of transparency in CRU, but were more sympathetic. “CRU accepts with hindsight”, they write, “that they should have devoted more attention in the past to archiving data and algorithms and recording exactly what they did. At the time the work was done, they had no idea that these data would assume the importance they have today and that the Unit would have to answer detailed inquiries on earlier work.” They also note that CRU should not have had to respond to Freedom of Information requests for data which they did not own (such as weather station records).

Just last week, the final investigation, headed by Sir Muir Russell on behalf of UEA, found that “their rigour and honesty as scientists are not in doubt.” Is this starting to seem a bit repetitive? To illustrate their point, over the course of two days, they independently reconstructed the global temperature record using publicly available data, and came to the same conclusion as CRU. Again, there was the criticism that CRU was not as open as it should have been. They also noted that an obscure cover figure for a 1999 World Meteorological Organization report, constructed by Phil Jones, did not include enough caveats about what was proxy data and what was instrumental data. However, the more formally published, and much more iconic, graphs in Mann 98 and the IPCC TAR, were fine.

There have been some great comments on the results of these investigations since they were released, especially by scientists. Here are some samples:

[The CRU researchers] are honest, hardworking scientists whose reputations have been unjustifiably smeared by allegations of unscrupulous behaviour…I hope that the media will devote as much attention to this comprehensive dismissal of the allegations as it did to promoting the hysteria surrounding the email theft in the first place. Will the Daily Telegraph now retract its claim that the emails revealed “the greatest scientific scandal of our age” and apologize unreservedly to Phil Jones? Will there now be a public inquiry about the erroneous, shallow and repetitive nonsense promulgated in the media over this affair? If there is a scandal to be reported at all, it is this: the media stoked a controversy without properly investigating the issues, choosing to inflate trivialities to the level of an international scandal, without regard for the facts or individuals affected. This was a shameful chapter in the history of news reporting. -Raymond Bradley, director of the Climate System Research Center at the University of Massachusetts

The call for greater transparency and openness among scientists and their institutions is necessary and welcomed, but certainly they aren’t the only ones who deserve that reminder. What institution on the planet would pass muster under such intense scrutiny? Certainly not the U.S. government agencies, which often deny or impede FOIA requests, or global corporations like BP, Massey Energy and Koch Industries, which seem to revel in hiding information from the public all the time. More transparency is needed everywhere, not just among scientists in lab coats. -Brendan DeMelle, freelance journalist, DeSmogBlog

[The Muir-Russell report] makes a number of recommendations for improvements in processes and practices at the CRU, and so can be taken as mildly critical, especially of CRU governance. But in so doing, it never really acknowledges the problems a small research unit (varying between 3.5 to 5 FTE staff over the last decade) would have in finding the resources and funding to be an early adopter in open data and public communication, while somehow managing to do cutting edge research in its area of expertise too. -Steve Easterbrook, computer science professor at the University of Toronto

I agree with these statements. I think that we are holding scientists in general, but especially climate scientists, to a far higher standard than any other group of people in the world. We need to relax a bit and realize that scientists make mistakes, and that innocent mistakes are not evidence of fraud that will bring a long-standing theory tumbling down. We need to realize that scientists are employees like any others, who don’t always follow ideal actions in every professional situation, especially when they are under intense pressure that includes death threats and accusations of criminal activity.

However, at the same time, we need to start holding other groups of people, especially journalists, to a higher standard. Why has the media been able to get away with perpetuating serious allegations without first investigating the what really happened, and without publishing explicit retractions and apologies when the people whose reputations they smeared are found innocent? Why haven’t there been four official investigations into who stole these emails, and why?

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All Is Not Lost

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I really enjoyed reading two recent polls conducted by George Mason University’s Center for Climate Communication. In particular, the results made me wonder why the US government still hasn’t passed a climate bill.

For example, US presidents have been saying for over a decade that it is unfair to force their industries to reduce emissions if developing countries do not have similar targets. However, only 8% of American adults share this view, and 65% believe that “the United States should reduce its greenhouse gas emissions regardless of what other countries do.” 77% agree that CO2 should be regulated, and 65% would like to see an international treaty signed.

The only solution which had less than 50% support was a tax on gasoline, even if it was revenue-neutral: offset by a decrease in income tax rates. This opposition can’t really be a case of people worrying about money. In this hypothetical situation, taxes aren’t being increased – they’re just being moved around, in a way that actually gives people more control over how much they are charged. Perhaps the public would prefer a more laissez-faire approach, or perhaps they had a knee-jerk reaction to the word “tax”. It’s not like the revenue-neutral aspect of this solution is well-known to most.

When the poll was broken down by political party, there were some surprising results that ran contrary to what one hears in the halls of Congress. 64% of Republicans support regulating CO2. Only 30% think that protecting the environment reduces economic growth and costs jobs.

Overall, the poll showed very strong support among Americans for action that still hasn’t happened, largely because a very vocal minority has had a disproportionate influence on the policy debate. If there was a referendum today, Kyoto targets and the cap-and-trade bill would pass with flying colours.

This support was even more interesting when compared to the questions regarding science. Only 61% of Americans think that the Earth is warming, and only 50% think that it is due to human activities. 45% think “there is a lot of disagreement among scientists about whether or not global warming is happening”, and only 34% were aware of the existing consensus.

The discrepancy between scientific understanding of the issue and support for mitigation shows that Americans, in general, practice risk management when it comes to climate change. Even if they’re not sure whether or not there is a problem, they understand what is at risk, and are willing to take action to prevent major consequences. Greg Craven, you got your wish.

I think that the misconception of a voracious scientific debate, apart from being perpetrated by the media, stems partly from the fact that most of the public lacks the experience to distinguish between scientific and quasi-scientific debates. Competing hypotheses, published in leading journals, seen as the frontier of the field….that’s a scientific debate. Editorials, written by anyone other than a scientist publishing in the field, claiming to refute an overwhelming consensus? Can’t even come close. However, I suspect that many would categorize the second as “scientific debate”, simply because it’s their only encounter with science.

All is not lost, though. 81% of Americans trust scientists as a source of information about global warming. That’s more than they trust any other source that was mentioned in the question. And 20%, 27%, and 29% say that they need a lot more, some more, or a little more information, respectively. Maybe all that needs to happen is for us to speak louder – because people are ready and willing to listen.

How We Should Communicate

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I really enjoyed this post by Andrew Freedman on the Washington Post blog Capital Weather Gang. I think it is written at the perfect level – basic enough for new readers to catch up on current events, while including enough creative insights to keep the interest of climate science enthusiasts.

The article covers the attempts of Dr Andrew Weaver, a top Canadian climate modeler, to fight back at the misinformation that has been willingly spread by top media outlets throughout the past few months. Here is an excerpt:

In late April Weaver filed suit against the National Post, a Canadian newspaper that has run numerous articles extremely critical of Weaver’s work and those of his colleagues. For example, according to Wihbey, the Post has called Weaver “Canada’s warmist spinner in chief,” and “generally impute[ed] to Weaver various views that he claims he doesn’t have.” (Weaver’s requests that the newspaper correct the record by issuing retractions/corrections were unsuccessful).

In the lawsuit, Weaver, who was a lead author of one of the IPCC’s working groups for its 2007 report, claims the articles include “grossly irresponsible falsehoods that have gone viral on the Internet.” Among those claims is that Weaver has turned against the IPCC and its conclusions, as trumpeted in this story in late January.

“If I sit back and do nothing to clear my name, these libels will stay on the Internet forever,” Weaver stated. “They’ll poison the factual record, misleading people who are looking for reliable scientific information about global warming.”

I am impressed at Dr Weaver’s courage and persistence to improve the accuracy of science journalism. For an issue that has potential consequences of an unprecedented scale in human history, we should be able to trust what the media tells us.

Something else I enjoyed was a sketch by Mitchell and Webb, a British comedy duo, making fun of how politicians pretend to promise action on climate change. Enjoy.

Illogic

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Here’s a great quote from a great article posted on the Nation. Thanks to Tim Lambert for the link.

Yet when it comes to coverage of global warming, we are trapped in the logic of a guerrilla insurgency. The climate scientists have to be right 100 percent of the time, or their 0.01 percent error becomes Glaciergate, and they are frauds. By contrast, the deniers only have to be right 0.01 percent of the time for their narrative–See! The global warming story is falling apart!–to be reinforced by the media.

Something Unexpected

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The differences between the Canadian and American political systems amaze me.

Whenever anyone mentions greenhouse gas emissions reductions in the States, people argue, journalists rant about dire economic costs, and Senators stand up and say that cap-and-trade is completely unnecessary because CO2 is plant food.

But here in Canada, the government will be voting on greenhouse gas targets next Wednesday, and I didn’t know a thing about it until DeSmogBlog mentioned it. None of the mainstream media outlets or other Canadian climate blogs I follow said a word about it. Maybe they didn’t know either.

Which is really quite strange, seeing as the federal government likes to call a 3% reduction from 1990 levels “aggressive action” and make a whole website about it, featuring a picture of Stephen Harper planting a tree. You’d imagine that, now that they’re considering a cut of 25% from 1990 levels by 2020, and 80% by 2050, they would make sure that every citizen in the country knew how responsible they were being.

The bill is known as C-311, or the Climate Change Accountability Act, and I encourage you to all read it here, it’s not very long. It’s been around for a few years, and even passed through the House once, but it had to restart several times due to various prorogations. Now it’s finally ready to be voted on by the House, and they’re doing that vote on Wednesday.

I’m not sure how much support this bill has from the MPs, but I sure hope it passes, because it would actually put us in line with the EU. Yes, no more number games of shifting around the baseline years – the proposed targets actually fall within the UN’s recommendations to avoid 2 C of warming.

Something even better about these targets, though, is this:

The Minister shall, within six months after this Act receives royal assent, prepare and lay before both Houses of Parliament an interim Canadian greenhouse gas emissions target plan for the years 2015, 2020, 2025, 2030, 2035, 2040 and 2045. The target plan shall

(a) establish a Canadian greenhouse gas emissions target for each of those years;

(b) specify the scientific, economic and technological evidence and analysis used to establish each target, including consideration of the latest reports from the Intergovernmental Panel on Climate Change and the most stringent greenhouse gas emissions targets adopted by other national governments; and

(c) show that each target is consistent with a responsible contribution by Canada to the UNFCCC’s ultimate objective of preventing dangerous anthropogenic interference with the climate system and with Parliament’s strong commitment to the Kyoto Protocol.

Bill C-311 isn’t just an empty promise. It makes the targets that we need attainable. If we could actually pass this, it would be the first time in my short life that I was impressed with the government and felt that politics was doing its job of protecting the interests of its citizens, rather than squabbling and trying to sabotage the other parties.

Update: It passed! Now on to the third reading. If it passes that, it moves to the Senate.

What The Press Should Cover, and Won’t

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The first of three investigations into the CRU emails has been released. You can read the British House of Commons’ entire report here, but I found the summary on page 7 to be just as useful. In part, it reads:

We believe that the focus on CRU and Professor Phil Jones, Director of CRU, in particular, has largely been misplaced. Whilst we are concerned that the disclosed emails suggest a blunt refusal to share scientific data and methodologies with others, we can sympathise with Professor Jones, who must have found it frustrating to handle requests for data that he knew – or perceived – were motivated by a desire simply to undermine his work.

In the context of  the sharing of data and methodologies, we consider that Professor Jones’s actions were in line with common practice in the climate science community. It is not standard practice in climate science to publish the raw data and the computer code in academic papers. However, climate science is a matter of great importance and the quality of the science should be irreproachable. We therefore consider that climate scientists should take steps to make available all the data that support their work (including raw data) and full methodological workings (including the computer codes). Had both been available, many of the problems at UEA could have been avoided.

We are content that the phrases such as “trick” or “hiding the decline” were colloquial terms used in private e-mails and the balance of evidence is that they were not part of a systematic attempt to mislead. Likewise the evidence that we have seen does not suggest that Professor Jones was trying to subvert the peer review process. Academics should not be criticised for making informal comments on academic papers.

In the context of Freedom of Information (FOIA), much of the responsibility should lie with UEA. The disclosed e-mails appear to show a culture of non-disclosure at CRU and instances where information may have been deleted, to avoid disclosure. We found prima facie evidence to suggest that the UEA found ways to support the culture at CRU of resisting disclosure of information to climate change sceptics. The failure of UEA to grasp fully the potential damage to CRU and UEA by the non-disclosure of FOIA requests was regrettable. UEA needs to review its policy towards FOIA and re-assess how it can support academics whose expertise in this area is limited.

DeSmogBlog also has a great summary which you can read here.

We know that the system of climate science is not perfect, and that the folks at CRU did not handle things in the best of ways all the time, but who ever does, especially when you are the target of organized campaigns to discredit your field? The real problem, though, is that everyone who keeps up with North American or British news heard that climate scientists were accused of fudging and manipulating data. There is no evidence to support these allegations, and the House of Commons’ report confirms this. However, I’m not naive enough to believe that the media will cover the result of this “scandal” as intensely as they covered the allegations themselves.

Imagine that you read in the newspaper that a man has been charged with murder. It will be months before you find out the verdict of his trial, and unless it’s OJ Simpson, you probably won’t hear the verdict at all. Many, perhaps most, people would assume that the man is guilty.

We assume that allegations have merit, when – at least when it comes to climate science – they just as often do not.

Staying Sane

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A long time ago, I learned to turn off the emotional half of my brain – can’t remember whether it’s right or left – when I read studies about climate change. I look at model results and projections from a purely analytical standpoint. I register how awful the scenarios are, but I don’t let it all the way in. I don’t let myself really think about the consequences. Instead, I think about how cool it is that we can study climate in this way, and how powerful math can be, so I find it quite easy to stay positive and not go completely insane.

I find this much more difficult when I read about climate change communication or policy. I think the analytical, math-loving side of my brain doesn’t have anything to do, so the full weight of the issue falls on the emotional half, and I go sort of nuts.

Take, for example, the bill that’s close to passing through the South Dakota government, requiring schools to teach climate change in a “balanced” fashion, framing it as a “largely speculative theory” that is disproven by astrology (?) Look at how US Senator James Inhofe, former Chairman of the Senate Committee on Environment and Public Works, has decided to criminally investigate 17 climate scientists with no evidence of criminal activity. Or how misconceptions spread by several British journalists have even made it into the Globe and Mail. The only misinformation that doesn’t make me angry anymore is the writing of the Heartland Institute and S. Fred Singer, because it’s so ridiculous that it seems like satire, even if it’s intended to be serious.

How do you stand it? How do you stay sane? How do you walk around all day without feeling the heavy weight of the world’s future, tossed aside by people who won’t be around to care?

I find it easy to stay happy when I only look at the scientific side of this issue. But as public communication is becoming absolutely vital for climate scientists, we can’t submerge ourselves in math anymore. Just look at how many editorials Nature has written lately on the abysmal state of climate change journalism. Even the peer-reviewed literature can’t stay separate from public communication and policy.

Most of you have been at it longer than I have. How do you cope? We’re going to need to figure it out, because our sanity is needed now more than ever.

The Antithesis to Nitpicking

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Sometimes we have to step back and look at the big picture. We have to remember that not everyone has heard or believed the one about global warming stopping in 1998. Denialists centre around nitpicking and ideas that global warming is a “house of cards”, so we respond the same way: countering all the “mistakes” they claim to have found.

In reality, climate change is an incredibly robust phenomenon that we’ve known about for decades – and the basic physics behind it, for over a century. It’s not some new, shaky discovery. It’s not going to be overturned because scientists at CRU do not always say nice things about their critics.

So I was very pleased when I opened up YouTube today to see that Peter Sinclair’s latest video was all about this big picture. If I had to choose just one of his videos to share with everyone I knew, this would certainly be it. This is the kind of message we need to get out there; this is the kind of angle we need to take.

IPCC Reform

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The IPCC is far from ideal, and we knew this even before word got out that WG2 had made several minor mistakes. I’ve written about this before – here I discuss how the IPCC is naturally biased towards understating climate change: being too optimistic in its results. And here I discuss the difference in public attention when the IPCC understated central claims (such as sea level rise, Arctic sea ice melt, and emission scenarios) to when they overstated a detail that didn’t even make it into the technical summary – exactly how fast the Himalayan glaciers would melt.

Several British journalists have managed to construct several other “scandals” in the IPCC claims, which have little to no merit. Tim Lambert has spent the past few weeks investigating the legitimacy of these allegations, and one thing stands out above all others: facts do not matter in the way the media reports alleged IPCC mistakes or misconduct. One journalist in a minor British paper can make an erroneous claim that shouts “IPCC scandal”, and even after scientists have patiently explained, multiple times, why it is untrue, the claim is repeated in every major newspaper in the world. Consequently, even though virtually all of these “scandals” have to do with the WG2, the opinion pages use it as an excuse to vehemently question the idea that humans are causing the Earth to warm. This is obviously WG1 material, which is based on the laws of physics and decades of peer-reviewed science – but that doesn’t matter to the media, does it?

For people like us, who are so intent on scientific accuracy, it is incredibly frightening when accuracy becomes irrelevant in the sources that virtually everyone else relies on for climate change information. Even after factual errors that fundamentally change the message of the story are pointed out, no retraction is printed, and the authors are dealt no consequences. As scientists and concerned citizens, our greatest weapon is truth. But that can no longer be enough – not when our fourth estate drops its responsibility to truth, at least for this issue.

The IPCC was formed in the late 80s, and the relationship between climate science and the rest of the world has changed fundamentally since then. We have gained much more understanding of what climate change could mean for the world, so creating a document that encompasses absolutely everything we know is longer and more tedious. Governments fearful of climate change action have abused their powers of IPCC editing and review, as Stephen Schneider describes in his excellent book Science as a Contact Sport. Special interests muddled the lines of communication between scientists and the public, and when, due to the Internet, this communication became impossible to stop, the special interests decided to smear the reputations of scientists, scientific organizations, and science itself. The media and the public fell willingly to this muddling and smearing, so these special interests have gained far more influence than truth should allow them.

Is it necessary, or even desirable, to reform the structure of the IPCC to better suit its communication with the public? In terms of producing the most accurate science, I feel that it’s doing just fine the way it is, with the exception of needing some new WG2 review editors, and a delayed deadline for the WG2 and WG3 publications (instead of having all three reports released simultaneously).

Nature recently published recommendations from five diverse climatologists as to how to reform the IPCC. Subscription or payment is needed to read the full article, so I’ll give a quick summary here:

Mike Hulme wants to split the IPCC into three – a Global Science Panel that frequently publishes smaller reports about WG1 topics, five or ten Regional Evaluation Panels that report on region-specific WG2 topics, and a Policy Analysis Panel that frequently publishes examinations of different policy options.

Eduardo Zorita wants the IPCC to employ full-time scientists, instead of doing all the work on a volunteer basis.

Thomas Stocker wants the IPCC to stay the way it is, but to pay extra attention to following their self-imposed rules.

Jeff Price wants to select more lead authors to produce “short, rapidly prepared, peer-reviewed reports” instead of a set of massive ones every six years.

John Christy wants the IPCC to be removed from UN oversight and adopt an open, continually updating “Wikipedia” structure. I think a more accurate allusion to Christy’s proposition is the Encyclopedia of Earth, which has lead authors and a basic review system.

Personally, I agree with Jeff Price’s proposal. Mike Hulme’s seems to be very similar, and I like the way he separates and organizes the different panels. John Christy’s idea of a continually updating report intrigues me, but the more open approach to peer-review and a policy to “hear all sides” could easily be abused through artificial balance – equality over accuracy.

Any thoughts, further suggestions, background information to share? What changes, if any, should be made to the IPCC? And how can we possibly immunize the public to this incredible excuse to be misled?

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How to Prove Global Warming Wrong

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Over the past twenty years, vested interests and political lobby groups have done a fantastic job confusing the public about anthropogenic climate change. To many, they seem to have proven the whole theory wrong.

But how could you actually prove global warming wrong – not just in the minds of the public, but through the established scientific process? What scientific discoveries – if they held up through peer-review, further criticism, and replication – would render climate change a non-problem?

One of the surest ways to stop all this cap-and-trade discussion would be to disprove the greenhouse effect itself – the mechanism by which the Earth absorbs and emits the same energy multiple times, due to the presence of greenhouse gas molecules that “bounce it back”. This keeps the Earth substantially warmer than it would be otherwise. Additionally, if the concentrations of greenhouse gases increase, so will the temperature of the Earth. This process was first hypothesized by Joseph Fourier in 1824, and was experimentally confirmed by John Tyndall in 1856. The first prediction of eventual man-made global warming came from Svante Arrhenius, in 1896. It wasn’t a theory as much as a logical result of a theory, one that was deeply rooted in physics and chemistry.

Unless our understanding of entire fields of physical science is totally off base, we can be sure that our greenhouse gas emissions will cause climate change eventually. But hey, if you could overturn all of thermodynamics, you wouldn’t have to worry about carbon taxes.

  • Cheap-out option: Svante Arrhenius was Swedish, but his name sounds sort of Russian, and 1896 wasn’t very long before the Russian Revolution. Therefore, Arrhenius was a Communist, and none of his scientific work can be trusted.

Knowing that something is sure to happen eventually, though, is different from knowing that it is happening right now with substantial speed. We know that the Earth is warming – even if you found some statistical way to disprove three separate temperature records, the physical and biological systems of our planet still stand: 90% of observed changes in the natural world, like the blooming of flowers, the peak flows of rivers, and the spawning of fish, are in the direction expected with warming (Rosenzweig et al, 2008).

But how do we know that the warming is caused by us? Climate change has been caused many times in the past by factors unrelated to greenhouse gases – like solar influences, whether they’re direct (a change in solar output) or indirect (a change in the Earth’s orbit). How do we know that’s not happening now?

If the warming was caused by the sun, the atmosphere would warm uniformly at all levels. However, if the Earth was warming from greenhouse gases, the troposphere (the layer of the atmosphere closest to the planet) would warm while the stratosphere (the next level up) would cool. This is because more heat is getting bounced back to the surface by greenhouse gases, and is subsequently prevented from reaching the stratosphere.

A cooling stratosphere has been described as the “fingerprint” evidence of greenhouse-induced warming. And, in fact, the stratosphere has been cooling over the past 30 years (Randel et al, 2009). Therefore, if you could somehow show that something else was causing this pattern of a warming troposphere and a cooling stratosphere, and that the significant, anthropogenic rise in greenhouse gases was somehow not affecting it, you would have a case for global warming being natural.

Update (18/2/10): About half of this cooling can be attributed to ozone depletion, and the other half can be attributed to greenhouse gases (NOAA, 2006). The flat trend in stratospheric temperatures from 1995-2005 (see the Randel citation above) can be explained by the recovery of ozone, which is temporarily offsetting the greenhouse gases. Interesting how the temperature of the stratosphere has just as many factors as the temperature of the troposphere…..but in both cases, you can’t explain the temperature trends without including human activity. Scott Mandia has a great explanation here.

  • Cheap-out option: Omit the explanation of why greenhouse warming causes stratospheric cooling. Just point to the graph that goes down and say, “The atmosphere is cooling! Therefore, the IPCC is a hoax!”

Finally, even if you couldn’t disprove that global warming is expected, observed, and anthropogenic, you could still show that it isn’t very significant. The way to do this would be to show that climate sensitivity is less than 2 C. Climate sensitivity refers to the amount of warming that would result from a doubling of carbon dioxide equivalent, and 2 C is generally accepted as the maximum amount of warming that our society could endure without too much trouble. The current estimates for climate sensitivity, in contrast, average around 3 C (a range of 2-4.5), and it is very unlikely to be less than 1.5 C (IPCC AR4).

However, a climate sensitivity of less than 2 C only means that climate change isn’t a problem if our greenhouse gases stop at a doubling of carbon dioxide equivalent from pre-industrial levels. Even without taking methane and other greenhouse gases into account, this brings us to a CO2 concentration of 560 ppm, which we are well on track to surpass, even with cap-and-trade. So you’d have to argue for a climate sensitivity of even less. Seeing as we’ve already warmed 0.8 C, it doesn’t leave you with a lot of wiggle room.

  • Cheap-out option: Build a climate model that does what you want it to, without any regard for the laws of physics. ExxonMobil will probably sponsor the supercomputers. Widely publicize the results and avoid peer-review at all costs.

Daunting tasks, certainly. But if you really believe that global warming is natural/nonexistent/a global conspiracy, this is the way to prove it. If you managed to prove it, and change the collective mind of the scientific community (not just the public), you’d probably win a Nobel Prize. So it’s certainly worth your time and effort.