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Daily Mangle

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Yesterday, the Daily Mail of the UK published a predictably inaccurate article entitled “Climategate U-turn as scientist at centre of row admits: There has been no global warming since 1995”.

The title itself is a distortion of what Jones actually said in an interview with the BBC. What Jones actually said is that, while the globe has nominally warmed since 1995, it is difficult to establish the statistical significance of that warming given the short nature of the time interval (1995-present) involved. The warming trend consequently doesn’t quite achieve statistical significance. But it is extremely difficult to establish a statistically significant trend over a time interval as short as 15 years–a point we have made countless times at RealClimate. It is also worth noting that the CRU record indicates slightly less warming than other global temperature estimates such as the GISS record.

The article also incorrectly equates instrumental surface temperature data that Jones and CRU have assembled to estimate the modern surface temperature trends with paleoclimate data used to estimate temperatures in past centuries, falsely asserting that the former “has been used to produce the ‘hockey stick graph’”.

Finally, the article intentionally distorts comments that Jones made about the so-called “Medieval Warm Period”. Jones stated in his BBC interview that “There is much debate over whether the Medieval Warm Period was global in extent or not. The MWP is most clearly expressed in parts of North America, the North Atlantic and Europe and parts of Asia” and that “For it to be global in extent, the MWP would need to be seen clearly in more records from the tropical regions and the Southern hemisphere. There are very few palaeoclimatic records for these latter two regions.”

These are statements with which we entirely agree, and they are moreover fully consistent with the conclusions of the most recent IPCC report, and the numerous peer-reviewed publications on this issue since. Those conclusions are that recent Northern Hemisphere warming is likely unprecedented in at least a millennium (at least 1300 years, in fact), and that evidence in the Southern Hemisphere is currently too sparse for confident conclusions. Mann et al in fact drew those same conclusions in their most recent work on this problem (PNAS, 2008).

Unfortunately, these kinds of distortions are all too common in the press nowadays and so we must all be prepared to respond to those journalists and editors who confuse the public with such inaccuracies.

Update 2/16/10. Phil Jones has confirmed to us that our interpretations of his comments in the BBC interview are indeed the correct ones, and that he agrees with the statements in our piece above. He and his CRU colleagues have also put up an response to some of the false allegations in a previous piece in the UK Guardian. We’ll report further such developments as they happen.

IPCC errors: facts and spin

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Translations: (Czech) (Svenska)

Currently, a few errors –and supposed errors– in the last IPCC report (“AR4”) are making the media rounds – together with a lot of distortion and professional spin by parties interested in discrediting climate science.  Time for us to sort the wheat from the chaff: which of these putative errors are real, and which not? And what does it all mean, for the IPCC in particular, and for climate science more broadly?

[Read more…] about IPCC errors: facts and spin

Please, show us your code

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The 1991 Science paper by Friis-Christensen & Lassen, work by Henrik Svensmark (Physical Review Letters), and calculations done by Scafetta & West (in the journals Geophysical Research Letters, Journal of Geophysical Research, and Physics Today) have inspired the idea that the recent warming is due to changes in the sun, rather than greenhouse gases.

We have discussed these papers before here on RealClimate (here, here, and here), and I think it’s fair to say that these studies have been fairly influential one way or the other. But has anybody ever seen the details of the methods used, or the data? I believe that a full disclosure of their codes and data would really boost the confidence in their work, if they were sound. So if they believe so strongly that their work is solid, why not more transparency?

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Are the CRU data “suspect”? An objective assessment.

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Kevin Wood, Joint Institute for the Study of the Atmosphere and Ocean, University of Washington
Eric Steig, Department of Earth and Space Sciences, University of Washington

In the wake of the CRU e-mail hack, the suggestion that scientists have been hiding the raw meteorological data that underpin global temperature records has appeared in the media. For example, New York Times science writer John Tierney wrote, “It is not unreasonable to give outsiders a look at the historical readings and the adjustments made by experts… Trying to prevent skeptics from seeing the raw data was always a questionable strategy, scientifically.”

The implication is that something secretive and possibly nefarious has been afoot in the way data have been handled, and that the validity of key data products (especially those produced by CRU) is suspect on these grounds. This is simply not the case. [Read more…] about Are the CRU data “suspect”? An objective assessment.

AGU Fall 2009

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16,000 attendees, thousands of cups of coffee and thousands of interesting conversations (and debates) about science.

That would be San Francisco, not Copenhagen of course.

There are a few of the RC crew there, so hopefully we’ll get some updates, but keep track of some other attending bloggers as well:

and the whole AGU blogroll. There are some live webcasts through the week that might be interesting too.

If there are any other attendees reading, feel free to post about any interesting sessions/talks you see. I’ll update the main post with anything particularly noteworthy.

Who you gonna call?

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The problem of ‘false balance’ in reporting — the distortions that can result from trying give equal time to the two perceived sides of an issue — is well known. In an excellent editorial a few years ago, the Seattle Post-Intelligencer called for a greater emphasis on truth, rather than ‘balance’. Unfortunately, this basic element of careful journalism seems to have been cast aside, especially in recent weeks.

I was both amused and stunned by the effort at ‘balance’ provided by Richard Harris’s report on NPR, in which he claimed that the peer review process was “so distorted” that neither John Christy nor Jim Hansen can get their work published. Notwithstanding the simple fact that both of these scientists publish regularly in leading journals, Harris’s attempt to present ‘both sides’ of the issue completely undermines his thesis. Christy thinks that the IPCC overstates the consequences of climate change, while Hansen thinks it understates it. If both feel the peer review process is biased against them, then it must be working rather well. This doesn’t mean they are wrong, but science is a conservative enterprise, and it is evident that neither of them has provided sufficient evidence for extraordinary claims. [Read more…] about Who you gonna call?

Something Is X in the State of Denmark

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We received a letter with the title ‘Climate Change: The Role of Flawed Science‘ which may be of interest to the wider readership. The author, Peter Laut, is Professor (emeritus) of physics at The Technical University of Denmark and former scientific advisor on climate change for The Danish Energy Agency. He has long been a critic of the hypothesis that solar activity dominates the global warming trend, and has been involved in a series of heated public debates in Denmark. Even though most of his arguments concern scientific issues, such as data handling, and arithmetic errors, he also has much to say about the way that the debate about climate change has been conducted. It’s worth noting that he sent us this letter before the “CRU email” controversy broke out, so his criticism of the IPCC for being too even handed, is ironic and timely.

Update – the link in the letter is now fixed. -rasmus

Copenhagen

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Nov. 24th, 2009 Copenhagen Diagnosis

The ‘Copenhagen Diagnosis‘, a report by 26 scientists from around the world was released today. The report is intended as an update to the IPCC 2007 Working Group 1 report. Like the IPCC report, everything in the Copenhagen Diagnosis is from the peer-reviewed literature, so there is nothing really new. But the report summarizes and highlights those studies, published since the (2006) close-off date for the IPCC report, that the authors deemed most relevant to the negotiations in Copenhagen (COP15) next month. This report was written for policy-makers, stakeholders, the media and the broader public, and has been sent to each and every one of the COP15 negotiating teams throughout the world.

Among the points summarized in the report are that:

The ice sheets are both losing mass (and hence contributing to sea level rise). This was not certain at the time of the IPCC report.

Arctic sea ice has declined faster than projected by IPCC.

Greenhouse gas concentrations have continued to track the upper bounds of IPCC projections.

Observed global temperature changes remain entirely in accord with IPCC projections, i.e. an anthropogenic warming trend of about 0.2 ºC per decade with superimposed short-term natural variability.

Sea level has risen more than 5 centimeters over the past 15 years, about 80% higher than IPCC projections from 2001.

Perhaps most importantly, the report articulates a much clearer picture of what has to happen if the world wants to keep future warming within the reasonable threshold (2°C) that the European Union and the G8 nations have already agreed to in principle.

The full report is available at www.copenhagendiagnosis.org. Three of us at RealClimate are co-authors so we can’t offer an independent review of the report here. We welcome discussion in the comments section though. But read the report first before commenting, please.

An open letter to Steve Levitt

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Dear Mr. Levitt,

The problem of global warming is so big that solving it will require creative thinking from many disciplines. Economists have much to contribute to this effort, particularly with regard to the question of how various means of putting a price on carbon emissions may alter human behavior. Some of the lines of thinking in your first book, Freakonomics, could well have had a bearing on this issue, if brought to bear on the carbon emissions problem. I have very much enjoyed and benefited from the growing collaborations between Geosciences and the Economics department here at the University of Chicago, and had hoped someday to have the pleasure of making your acquaintance. It is more in disappointment than anger that I am writing to you now.

I am addressing this to you rather than your journalist-coauthor because one has become all too accustomed to tendentious screeds from media personalities (think Glenn Beck) with a reckless disregard for the truth. However, if it has come to pass that we can’t expect the William B. Ogden Distinguished Service Professor (and Clark Medalist to boot) at a top-rated department of a respected university to think clearly and honestly with numbers, we are indeed in a sad way.

By now there have been many detailed dissections of everything that is wrong with the treatment of climate in Superfreakonomics , but what has been lost amidst all that extensive discussion is how really simple it would have been to get this stuff right. The problem wasn’t necessarily that you talked to the wrong experts or talked to too few of them. The problem was that you failed to do the most elementary thinking needed to see if what they were saying (or what you thought they were saying) in fact made any sense. If you were stupid, it wouldn’t be so bad to have messed up such elementary reasoning, but I don’t by any means think you are stupid. That makes the failure to do the thinking all the more disappointing. I will take Nathan Myhrvold’s claim about solar cells, which you quoted prominently in your book, as an example.

[Read more…] about An open letter to Steve Levitt

350

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I was quoted by Andrew Revkin in the New York Times on Sunday in a piece about the 350.org International Day of Climate Action (involving events in 181 countries). The relevant bit is:

Gavin A. Schmidt, a climate scientist who works with Dr. Hansen and manages a popular blog on climate science, realclimate.org, said those promoting 350 or debating the number might be missing the point.
“The situation is analogous to people trying to embark on a cross-country road trip to California but they’ve started off heading to Maine instead,” Dr. Schmidt said. “But instead of working out ways to turn around, they have decided to argue about where they are going to park when they get to L.A.”
“If you ask a scientist how much more CO2 do you think we should add to the atmosphere, the answer is going to be none.”

I’ve been told that some readers may have misinterpreted the quote as a criticism of the 350.org campaign itself. This was not the intent and in fact my metaphor wouldn’t have made sense in that context at all. Instead, it was a criticism of people who are expending effort arguing about whether 350 is precisely the right number for a long term target, or whether it should be somewhat higher or lower. Since we aren’t currently headed anywhere near 350 ppmv (in fact we are at 388 ppmv CO2 and increasing by about 2 ppmv/yr), we need to urgently think of ways the situation can turn around. Tapping into the creativity and enthusiasm shown by the 350.org campaigners will certainly be part of that process.

We discussed some of the thinking behind this ‘Target CO2‘ when Jim Hansen and colleagues’ paper first came out, where I think we made it clear that picking a specific CO2 target to avoid ‘dangerous’ climate change is an inexact science at best. The comments by Robert Brulle and Ray Pierrehumbert at DotEarth and James Hrynyshyn also highlight some of that complexity. And I think the suggestions by ‘Paulina‘ for how a tweaked article might have been clearer are very apropos.

However, as the final line in my NYT quote should make clear, personally I think the scientific case not increasing CO2 any further is very strong. Since the planet has not caught up with current levels of concentrations emissions (and thus will continue to change), picking an ultimate target that is less than today’s level is therefore wise. Of course, how we get there is much trickier than knowing where it is we should be going, but having a map of the destination is useful. As we discussed in the ‘trillionth ton‘ posting a couple of months back, how we get there also makes a difference.

In my original email to Andy Revkin, I had actually appended a line:

If you ask a scientist how much more CO2 do you think we should add to the atmosphere, the answer is going to be none.

All the rest is economics.

(and technology, and sociology, and psychology and politics etc.) but the point is that working out how we get there from here is the real challenge and the more people who are aware and involved in developing those solutions the better.