Posts Tagged ‘IPCC’

IPCC plus 20: a world warming but not frying

By Colby Cosh - Wednesday, December 12, 2012 - 0 Comments

The CBC provided us with an interesting case study in science reporting on Monday as its “community team” blog trumpeted “UN climate change projections made in 1990 ‘coming true.’

Climate change projections made over two decades ago have stood the test of time, according to a new report published Monday in the journal Nature.

The world is warming at a rate that is consistent with forecasts made by the UN’s Intergovernmental Panel on Climate Change 22 years ago.

Climate scientists from around the world forecasted the global mean temperature trend for a 40-year period, from 1990 to 2030—and at this halfway point the report authors have found the projections “seem accurate” after accounting for natural fluctuations.

These are absolutely all the numbers you are going to get out of this news item. And if you peruse the new assessment of the 1990 IPCC predictions, which was actually published on the Nature Climate Change website, what you find is a more nuanced picture than the CBC’s “They nailed it, no worries” interpretation implies.

David Frame and Dáithí Stone write that the 1990 IPCC report predicted a rise in global mean temperatures of between 0.7 degrees C and 1.5 degrees C by the year 2030; on a linear interpolation, we might have expected half the increase to have occurred by now. The actual observed warming during the past 20 years (almost all of it taking place in the first ten) has been in the vicinity of 0.35 degrees C to 0.39 degrees C, “on the borderline” of the range given in 1990. In other words, the IPCC’s point estimate was high, and the overall warming has been consistent with the outer confidence bounds of their stated prediction, but barely.

Frame and Stone think, with some justification, that this is a pretty good performance given the simplicity of the climate models available at the time. It’s especially good, they think, because the models could not predict what would happen in the economy, or below the planet’s crust. Their story is that the Earth caught a series of lucky breaks despite the substantive failure of greenhouse gas reduction efforts.

The highlighted [IPCC] prediction assumed a business-as-usual scenario of GHG emissions; three other scenarios were considered and in fact Scenario B (which assumed a shift to natural gas, a decrease in the deforestation rate, and implementation of the Montreal Protocol, all independent of global climate negotiations) was closer to the mark as of 2010, especially with respect to methane emissions… Of course, [even these Scenario B] predictions were based on idealized future scenarios that did not foresee the eruption of Mount Pinatubo, the collapse of the Soviet Bloc industry, or the growth of some Asian economies, so one could argue that the prediction is right for the wrong reasons.

The authors conclude by noting that predicting the future is a lot harder than predicting the past—and, unfortunately, the resolving power of crystal balls has not improved much since 1990.

…the 1990 prediction following [the IPCC's] business-as-usual scenario covered a full 0.4ºC range due solely to uncertainty in the climate sensitivity that has not narrowed substantially so far, whereas a larger range was implied by the examination of further scenarios of emissions and a larger range still should have been considered owing to uncertainty in the evolution of natural forcings and internally generated variability.

Believers in and skeptics of the threat from anthropogenic climate change will both find promising fodder in this paper for conversion into mountains of delicious hay. (Mind the carbon emissions, though.) I’ll resist the temptation to join in that exercise, but it is very clear that the authors’ “Well done” message to the IPCC carries a sizable asterisk. If the CBC is going to report on a scientific paper, why not show some indication somebody has read it?

  • 'I totally support my government'

    By Aaron Wherry - Thursday, February 25, 2010 at 1:49 AM - 65 Comments

    Maxime Bernier posts some of his interview with La Presse.

    Question: Should the scandals involving the IPCC serve as a reason for the Canadian government to abstain from doing anything until we know more about the issue?

    Answer: I quoted Prof Patterson who said this. I believe however it would be unrealistic to do nothing, for many obvious political reasons. My position is that we should be cautious instead of ambitious when tackling this issue. That’s why I totally support my government, which has shown caution even if it brought us criticism and condemnations from environmental activists.

  • Norwich, we still have a problem

    By Colby Cosh - Saturday, November 28, 2009 at 9:06 AM - 357 Comments

    Laymen who have understandably decided to accept what much of the media now treats as axiomatic–that humans are causing potentially catastrophic global warming–must now be suffering some anxiety over the leaked e-mails from the Climatic Research Unit. Is an opinion leader like George Monbiot right to view this as a serious matter, or should they believe the reassurances of somebody like, say, Toronto Star environment columnist Peter Gorrie?

    I ask solely as a matter of media-consumer interest, because, realistically, what Gorrie writes doesn’t matter to a climate-change skeptic, or to anyone with the time and the quantitative training to follow a scientific debate on his own. It matters to the guy on the subway who avoided Stats 101 as if it had horns and fangs, and that guy is now getting conflicting signals. I presume Gorrie would agree that his job is not just to confirm that reader’s prejudices–though people do like having their prejudices confirmed, and any argument a columnist can make will confirm somebody’s.

    Like other columnists covering the CRU leak, Gorrie zooms in on just one “example” from the e-mails; although the etymology and sound of that word “example” would seem to imply some element of randomness in the selection, many of these columnists are choosing the same e-mail, because it contains an apparent faux pas that is relatively easy to explain away:

    In one email, the research unit’s director, Phil Jones, refers to work by another scientist, Michael Mann, published in the journal Nature: “I’ve just completed Mike’s Nature trick of adding in the real temps to each series … from 1961 … to hide the decline.”

    “Trick” doesn’t refer to sleight of hand; it’s jargon for a good, useful solution to a research problem. The problem in question relates to the fact that one method used to estimate temperatures over centuries – measuring tree rings – doesn’t give good recent results. But actual observations, the “real temps,” were available.

    It’s much easier to understand “scandal” than even that simplified explanation.

    He’s right about the word “trick.” Scientists do use the word to describe simple solutions to sincere research problems. It does not, on its own, imply deception. The real problem with the Jones e-mail is the part about “hiding the decline.” The issue, really, is right there in Gorrie’s paragraph: tree rings appear to have serious problems as a means of inferring global surface temperatures from before human records were kept. As an abstract of the Briffa study Jones was discussing notes:

    …tree-ring density records become de-coupled from temperature after 1950, possibly due to some large-scale human influence that caused wood densities to decline. Thus, the reconstructed temperature record after 1960 is considered unreliable.

    Jones’ “trick” was to graft observed temperature data from after 1960 onto a line showing temperatures merely inferred from tree rings. If you just reported the tree-ring data straight-up, they would suggest that the earth has cooled since 1960, which conflicts with what we know was happening (assuming there are no biases in the temperature observations, but that’s another battleground several miles away).

    In one sense you could argue that this is a “trick” in the innocent meaning of the term, a real answer to a real problem: Jones only meant to “hide” a presumptively nonexistent “decline”. But an ordinary person looking at a graph doesn’t expect the underlying data to be spliced together from two different sources if the point of the graph is to highlight what one source (the tree rings) tells us. Moreover, the divergence between the predictions of the tree-ring model and real post-1960 temperatures is a legitimate problem in paleoclimate reconstruction. (“Some large-scale human influence” on “wood densities”? Oh, hell, what about the fairy hypothesis? Couldn’t woodland sprites have sprinkled magic dust on those trees?)

    In “hiding the decline”, Jones was thus proposing to “hide” a weakness in the research itself. IPCC peer reviewers squawked about this “hiding” when it was done in another way, by simply cutting off the data at 1960. As a matter of scientific ethics, Jones’s “trick” sucks. Though it’s still probably not one of the four or five most ethically troubling statements in the leaked CRU e-mails, even considering just the ones made by Jones.

    Gorrie could have minimized the offence in dealing with this cherry-picked example of malfeaseance; instead, he handwaved it away completely. But then there’s a lot of handwaving in this column, like the obnoxious complaint that environmental reporters are being asked to “parse e-mails” (which, as described above, he goes on to do in a tendentious, half-hearted way) instead of “focusing on the evidence of human-made climate change”. As if the debate over the CRU e-mails was anything other than an argument about the provenance and quality of the most important body of a posteriori evidence for human-made climate change.

    Gorrie also says, sympathetically, that climate scientists “resent having to respond to skeptics.” Well, who the hell doesn’t? That’s like saying that prosecutors resent the threat of having unfairly acquired evidence excluded from the courtroom, or that ballplayers resent the danger of getting picked off first base. They can resent it all they like, but it’s there in the rules of the game, for good reasons. Q: What do you call a scientist who can’t accept criticism from “skeptics”? A: Anything you like, as long as it’s not “scientist”.

  • Norwich, we have a problem

    By Colby Cosh - Wednesday, November 25, 2009 at 3:28 PM - 427 Comments

    I can’t say I am spectacularly surprised at the emerging scandal over private e-mails obtained from the servers of the University of East Anglia’s Climatic Research Unit, which is at the heart of the process that produces IPCC reports on climate change. Some of the controversial practices revealed by the leaked e-mail corpus, such as fidgeting with visual presentations of statistics in order to make them as impressive and sensational as possible, are just evil habits that nonetheless form part of the standard operating procedure of applied science. But others—ignoring requests for data sets from one’s scientific adversaries, playing politics with scientific editorial boards, denouncing criticisms as not being peer-reviewed while working behind the scenes to ensure that those same criticisms are shut out of the peer-reviewed literature—were already known parts of the climate-panic industry’s playbook.

    The CRU e-mails, whose veracity has so far held up to intense worldwide scrutiny and been generally confirmed by the University of East Anglia, reveal top IPCC contributors to be supercilious, inquisitorial, paranoid, nasty, thuggish, hypocritical, and, in general, trapped in an echo chamber of very modest dimension. If you didn’t already have a sense that all of this was true, you haven’t been paying close enough attention to the debate.

    If, on the other hand, you instinctively think that “Climategate” isn’t going to be a big deal in the long run, I would suggest contemplating the very earliest reactions of the climatology nerds at ClimateAudit.org, the global-warming skepticism site edited by Canadian researcher Stephen McIntyre (who is mentioned dozens if not hundreds of times in the CRU e-mails as a particularly intractable bête noire). In the hours immediately after the CRU leak, many members of the Climate Audit community, confronted with evidence of malfeasance and scumbaggery by the scientists who have been attacking skeptics as lunatics and astroturfers for two decades, at first reacted with… well, skepticism. And, in some cases, even sorrow. Sample quotes from the comment thread:

    • An ideological hacker smart enough to hack CRU is smart enough to manufacture a bombshell or two and seed it amongst the rest of the data. Treat “too good to be true” material with a lot of caution initially from such a source.
    • Folks I would run, not walk, away from this as quickly as possible. To think they would be stupid enough to not cover their tracks on this is not credible IMO. While parts are likely real, some could be added as embellishments meant to create the furor it is already creating in the skeptic community. Let’s not make any judgements on the authenticity until we are sure what we have here is real and not a plant.
    • I find this really quite shocking and distrubing. I mean it is one thing to think that such subversion is going on; it is quite another thing – if this is all undoctored – to read it. I don’t know whether to be elated (as a skeptic) or a little sad that this will reflect badly on science regardless.
    • I have concerns like others that this entire archive may be a “spiked” version of an otherwise legitimate (hacked) archive …but much of my concern is driven by the fact that I assume that things can’t be this blatant.

    More such examples could be cited. The point is that the skeptics suspected the contents of the CRU leak were too “good”—that is, too damaging to the cause of the global warming hypothesis and the IPCC—to be true. It now seems nearly certain that they are true. Under the circumstances, what George Monbiot calls “climate rationalists” can hardly maintain a posture of indifference and dismissiveness. Monbiot himself, displaying a courageous spirit of openness that his critics may not have anticipated, has been arguing as much: but voices of agreement on his side of the debate are so few that he admits “I have seldom felt so alone.”

  • Is the threat of climate change exaggerated?

    By Alex Shimo - Friday, March 13, 2009 at 6:25 PM - 27 Comments

    A growing number of people think the risk of climate change is exaggerated, according…

    A growing number of people think the risk of climate change is exaggerated, according to a Gallop poll. About 4 out of 10 Americans think the media overestimate the threat, the highest in a decade of polling. Although the majority still believe the media get it right or underestimate the problem, this number has been falling, while those who think its overblown is rising.

    bpg-iae_6umqs7-fda8tjq1

    What’s ironic about these stats is that they almost directly precede a statement by hundreds scientists that climate change is actually worse than we originally thought. Meeting in Copenhagen on Thursday, nearly 2,000 researchers issued a statement that global warming is not only “accelerating” beyond the worse predictions, but the changes were threatening to trigger “irreversible” climate shifts on the planet.” These statements, which update the the 2007 report by the Intergovernmental Panel on Climate Change, offer stark forecasts. The panel previously predicted a sea level rise of 18 to 59 centimetres by the end of the century. Those figures have now been revised upwards, to between 50 centimetres to one metre. When a consensus of international scientists warns that the problem is worse than predicted, the media doesn’t need to exaggerate: accepting the facts is hard enough.

  • The Real Cost of Climate change

    By Alex Shimo - Tuesday, February 3, 2009 at 7:14 PM - 11 Comments

    No one argues that the cost of tackling climate change is going to come…

    No one argues that the cost of tackling climate change is going to come cheap, but a number of recent reports have put an exact price tag on it. And this global problem is about as expensive as they come. If you want to keep the planet cool, and stabilize the amount of carbon dioxide at 450 parts per million (ppm), which was the target set by the United Nations’ Intergovernmental Panel on Climate Change, that will cost $542 billion US per year, every year till 2030, according to the World Energy Outlook (WEO). The EU estimates that it about half that cost, or about $224 billion US per year. A research group called New Energy Finance sides with the WEO, putting the price tag at $515 billion US dollars a year.

    The discrepancies between these two estimates depend on how quickly you think renewable energies are going to improve and the cost will decrease. (The cost of renewable energy will certainly fall: solar power has fallen greatly in price as the technology has improved.) But can it come down quickly enough? Suppose you’re an optimist and low ball the cost, like the bureaucrats at the EU, then the cost of reducing emissions to tackle climate change is mere $224 billion US per year, or $276 billion CAD. That’s $276 billion each year for the next 20 years. Which makes one wonder, where is all this money going to come from?

From Macleans