More Questions about Climate Science

I talk a lot here about climate science, but I have a growing realisation that the vast majority of those who get exercised about this issue don’t know enough science to read papers in academic journals, and certainly are not excited about the issues that really attract scientific controversy, like string theory (someone has gone so far as to write a book about that with the stinging title, Not Even Wrong).

The real issue is fear that a fundamental change in the energy economy will cause a massive collapse in living standards. This fear is justified, but if mainstream climate science is right, we will need to make that change sooner or later, and the longer we delay, the harder it will be to get this change right without economic chaos. This fear is leading to a campaign that is not attacking the science as much as the scientists, which is why I set up a pro-science petition.

In response to my petition, Tim Curtin sent me a list of questions, which I repeat here with his permission:

You say: (1) "Stealing emails...", You have no evidence any were stolen, either they were up for grabs on ftp, or an insider blew the whistle.

(2) "magnifying the significance of errors" - actually the errors are beyond magnification, eg tippexing Roman glory days and the MWP

(3) "and invoking conspiracy theory" - the emails are very strong evidence of a well-organised conspiracy to pervert the progress of science

(4) " is no substitute for reasoned evidence-based debate" - a non sequitur. Actually Jones and his CRU abetted by Mann & Co took every possible means to suppress evidence-based debate (e.g. by preventing access to the evidence)...

(5) "Yet in the field of climate science...no one has presented a credible alternative theory, the usual approach to overturning a scientific theory". Actually there is overwhelming evidence from multivariate regressions that radiative forcing from increasing greenhouse gas concentrations in the atmosphere has no statistically significant impact on changes in mean max or min temperatures anywhere on earth once changes in surface solar radiation are taken into account. Watch this space, as not a single climate journal (eg Nature, Science, PNAS, JoC etc etc) will ever publish any paper on this, given that all their boards are controlled by friends of Jones et al (eg Schellenhuber, Rahmstorf, Schneider, Schmidt, Hansen, et al ad infinitum).

Let’s take this from the top.

An archive of emails from an institution appears on the Internet in various places. The authors of the emails have not given their permission for their private emails to be published. By any reasonable definition, that’s theft. It doesn’t matter who did it or how, or whether someone left the front door open. The police are investigating. The police generally only investigate crimes.

The “Roman glory days and the MWP”: The most obvious response is that human society is vastly different today, with huge cities and vast impoverished agricultural societies a few metres above sea level. In Roman or Medieval times, if the local climate became unsuited to human society, people could and did migrate. We don’t have that option today.

I’ve studied a number of temperature reconstructions. The further back you go, the bigger the uncertainties. I had a look at the papers flagged as containing the most reliable data on the medieval warm period on a contrarian web site (CO2 science) that collects material on this stuff. The earliest and latest peak were 600 years apart. While it is quite likely that the odd spot around the world was much warmer than it is today at some point in the past, that does not mean the global average was much higher. An increase in the global average is important because it has consequences like sea level rise, and pushing habitats uphill and away from the equator. If it was warmer during the MWP or Roman period than it is now, there would be evidence that sea level was higher at that time (at least very similar) whereas the only evidence I’ve seen (admittedly with very big error bars – but current sea level is outside those error bars) shows current sea level as the highest in 3,000 years.

Next: “emails are very strong evidence of a well-organised conspiracy”. I don’t agree. All we see is comment about how poor some other people’s work is (common backroom banter in science) and some conversations that are open to sinister interpretation but checking in the real world shows such sinister intent didn’t materialise. For example: talk of keeping certain work out of the IPCC did not lead to that work being excluded (it is in fact cited). Similarly for the “hide the decline” comment: it refers to the fact that tree ring reconstructions fail to match temperatures in the later half of the twentieth century, a problem Mike Mann describes in a paper in Nature – hardly concealment. This inconsistency between tree ring records and thermometer readings would be a problem for credibility of tree ring reconstructions if they were not cross-checked against many other measures. I don’t see the big conspiracy. I see scientists not watching every word in emails between colleagues. If that is a sinister conspiracy, you have a vivid imagination.

Then: “Mann & Co took every possible means to suppress evidence-based debate”. I agree they could have made a bigger effort to make everything public (e.g., CRU’s computer code) but this claim is an exaggeration. The data they did not make public is data that is not theirs to make public. The remedy for anyone wanting it is to go to the original source. In science, while maximum openness is useful and I fully support the concept, the best check on integrity of results is if they are independently reproduced from scratch, ideally with independently derived data. NASA provides full data sets and software for download. If I download everything and run the software exactly as NASA did in one of their papers, all I am doing is replicating their exact steps including their errors. Anyone who thinks the CRU temperature reconstruction flawed is welcome to start from scratch from publicly available data sources and show that they get an inconsistent result. This is how science normally proceeds. An astronomer reports a new star. Other astronomers use their own telescope to verify the find. They don’t demand a computer dump of the data generated from the original telescope.

Finally: “overwhelming evidence from multivariate regressions”: let’s see that evidence. You don’t have to publish in Nature to get your work out. There are many journals out there, and there is no evidence that those with a strong anti-AGW agenda cannot publish. Certainly, the likes of Richard Lindzen are able to publish, and what strikes me about the contrarian papers I’ve seen is that they are usually rather easy to debunk (even to the point of attracting a rebuttal in one case from a contrarian site). Are you suggesting there’s a bias where only the rubbish contrarian papers are published, and the good ones are not? That is implausible: it’s easy to publish a good paper (sound methodology, original results, defensible conclusions) as long as you are not fussy about where it’s published (a good journal, not necessarily top tier).

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Thanks for sending me the questions. I am happy to have discussion on this site. I do not snip comments, and only delete spam (but to cut spam, response to older articles are screened). I have absolutely no objection to attacking the science with better evidence, better theories, or both. This is how any scientist works. Attacking the scientists, not the science, is not constructive – hence my petition.

It further worries me that a large part of the lobby against climate science is attempting to reduce science to a matter of opinion. It is not. If a theory fits the evidence, it’s good. If it doesn’t, we need a better theory. If a new theory fits the evidence better, it replaces the old one. This methodology may be strange to those schooled in the arts or social sciences, but it’s a damn good one, and has taken us out of superstition to a worldwide technological society. Let’s not throw it away just because we are faced with a really hard problem if we accept the mainstream theory: the biggest change in the energy economy in over 100 years.

Addendum

To illustrate that the basics are really quite old, it's interesting to read this 1956 paper in American Scienist by Glilbert Plass (reprinted January-February 2010). Much of the detail has since been clarified and some of his errors fortuitously cancelled out so there has been real progress in the science since 1956 – as you would expect.

Replies to questions about climate science

One Terry today at The Australian asked some questions. Unfortunately the paper is a lousy forum to conduct a conversation because it updates slowly and is patchy in posting comments. Also, Terry, the answers to your questions are readily available. It’s not my fault if Australia’s only national daily doesn’t report science much above the level of superstition and rumour. I would offer my humblest grovelling apologies if it were my fault. For that, you must go to Mr Murdoch.

Tom Clark, Philip Machanick, Sancho, et al

Why not settle the discussion and show us sceptics the proof for the following:
1. That current anthropogenic CO2 emissions are the major cause of global warming. Bear in mind that the physics shows that the amount of warming from CO2 decreases as the concentration increases. Thus there has to be a huge forcing, what is it?
2. That the minimal warming from anthropogenic CO2 causes climate change. Please detail which elements of the climate (storms, drought, heat, floods, tornadoes, etc.) are changing, and the proof that the major cause is anthropogenic CO2.
3. The earth has been warmer in its recent past (Roman and Medieval periods), and these warm periods were very beneficial to mankind. Thus if (and it’s a big if) anthropogenic CO2 has any real influence on the global temperature, why should we be concerned about living in temperatures that existed, to the benefit of mankind, in the past 2000 years?

When you answer, bear in mind that computer predictions are not science.
Also the recent (30 years) global temperature readings are badly compromised, not least from the fact that the original 6000 measuring sites have been reduced to 1500, and it wasn’t the warmest locations that were removed.

Just this once, I’ll do your homework for you. But listen up: you can find all this stuff yourself. The trick is to use Google Scholar, rather than regular Google, which turns up masses of dross. Unfortunately a good fraction of the research literature is paywalled, but NASA makes all theirs public so I will use them disproportionately so you can check my sources. I include a few paywalled papers where the important detail is in the free to view abstract.

1. Scientists have known since the 19th century that the relationship between CO₂ concentration and warming is logarithmic. Please don’t parade this fact as evidence of the ignorance of scientists, but rather as evidence of your ignorance of the mainstream. Forcing per doubling of CO₂ is 4W/m² [Hansen et al. 2005]. To put this into context, a 2% increase in solar irradiance adds about 4W/m² [Hansen et al. 2008]. A 24 W/m² increase in solar irradiance only over summer, accompanied by a 4-day increase in the duration of summer, caused by a change in axial tilt [Huybers 2006], is enough to tip the earth out of an ice age, so 4W/m² is a big change – especially as it’s not limited to one season and a limited part of the planet. The maximum variance in solar irradiance since satellite records began is 0.36%, less if you smooth the data to take into account that the biggest variations are very short-term (graph below from TSI Composite Database plot of data 1978-1999). There is no known theory of climate that can use solar variability and other natural influences to reproduce temperature variation since the 1950s. We can only reproduce the trend by models that include natural influences and anthropogenic warming.

2. No serious climate scientist is claiming that the current level of warming is resulting in major increases in storms etc. Yet. There are however measurable effects like loss of Greenland and Antarctic ice mass [Velicogna 2009 – see figures from this paper below] – and many others like glacier retreat, change in species range, and accelerated rates of extinction. You can find plenty of evidence for these if you look. If you want catastrophic effects before you accept firm evidence of climate change, you’re crazy. Predictable effects such as shrinking glaciers are enough for me, especially as many of these metrics are happening faster than predicted.

Antarctic Ice Loss (blue data points: unfiltered)	Greenland Ice Loss (blue data points: unfiltered)

3. The evidence of warming in the Medieval Warm Period is patchy and unreliable, and recent evidence suggests the warming was not as fast as that at present [Loso et al. 2007]. A conspiracy-theoretic site styling itself “CO2 science” has an extensive archive of papers purporting to support a globally warmer period in medieval times. I examined the papers they claimed had the highest-quality evidence, and found the temperature peaks varied by as much as 600 years in different locations around the world. That is not a globally warm period. I haven’t seen the evidence that Europe was warmer in Roman times than it is now; there certainly is unlikely to be solid evidence of warming on a worldwide scale for the simple reason that the resolution of our methods of measuring temperature is poor that far back in time. In any case, “warmer” is a relative term. Our current temperatures are on the back of greenhouse warming that hasn’t concluded. Even if we do not add more CO₂ to the atmosphere, we have another 0.5°C of warming or so due from slower feedbacks. The Roman world and Medieval Europe may have benefited from local warming from a sub-optimal climate for agriculture to a better climate for agriculture. Warming today is unlikely to have that effect: much of the world’s rice crop for example is grown at close to its temperature limits for high yields, a concern for food production in China [Tao et al. 2006].

On your other comments, if computer predictions aren’t science, we are going to have to stop doing biology and most other branches of modern science. Computer models are no different than mathematical models, except they can process a lot of information fast. Like mathematical models, they can be wrong. This is why scientists check on each other, and build their own models from scratch, rather than rely on a popular model to be correct.

The claim that measurements are compromised by reduction in climate stations is rubbish, especially the claim that the removed sites were from cooler areas. Temperature measurements are not in absolute readings, but anomalies, deviations from a baseline. The baseline for each weather station is based on typical measurements for that type of station. The number used from each station in the overall temperature calculation is not its temperature but its difference from the baseline. This method was introduced for several reasons, one of which is to avoid exactly the sort of problem to which you allude. NASA documents their approach in detail and provides all the computer programs and data. Check it yourself.

 I have a question for you now:

If climate science really is junk, why is it necessary to oppose it with vaudeville acts, personal attacks, stealing email and clear and obvious lies?

And if you agree with me is that science is about supporting theories with evidence, not personal attack and harassing scientists with whom you disagree, sign my petition.

References

[Hansen et al. 2005] Hansen, J., Mki. Sato, R. Ruedy, L. Nazarenko, A. Lacis, G.A. Schmidt, G. Russell, I. Aleinov, M. Bauer, SS. Bauer, N. Bell, B. Cairns, V. Canuto, M. Chandler, Y. Cheng, A. Del Genio, G. Faluvegi, E. Fleming, A. Friend, T. Hall, C. Jackman, M. Kelley, N. Kiang, D. Koch, J. Lean, J. Lerner, K. Lo, S. Menon, R. Miller, P. Minnis, T. Novakov, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, D. Shindell, P. Stone, S. Sun, N. Tausnev, D. Thresher, B. Wielicki, T. Wong, M. Yao, and S. Zhang 2005. Efficacy of climate forcings. J. Geophys. Res. 110, D18104, doi:10.1029/2005JD005776
[Hansen et al. 2008] Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos, 2008: Target atmospheric CO₂: Where should humanity aim? Open Atmos. Sci. J., 2, 217-231, doi:10.2174/1874282300802010217
[Huybers 2006] Peter Huybers. Early Pleistocene Glacial Cycles and the Integrated Summer Insolation Forcing, Science 313 (5786), 508, 28 July. [DOI: 10.1126/science.1125249]
 [Loso et al. 2007] MG Loso, RS Anderson, SP Anderson, PJ Reimer, P J. Sediments Exposed by Drainage of a Collapsing Glacier-Dammed Lake Show That Contemporary Summer Temperatures and Glacier Retreat Exceed the Medieval Warm Period in Southern Alaska, Eos Trans. AGU, 88(52), Fall Meet. Suppl., Abstract PP44A-01
[Tao et al. 2006] Fulu Tao, Masayuki Yokozawa, Yinlong Xu, Yousay Hayashi, Zhao Zhang, Climate changes and trends in phenology and yields of field crops in China, 1981-2000, Agricultural and Forest Meteorology, Volume 138, Issues 1-4, 29 August, Pages 82-92, ISSN 0168-1923, DOI: 10.1016/j.agrformet.2006.03.014
[Velicogna 2009] I Velicogna. Increasing rates of ice mass loss from the Greenland and Antarctic ice sheets revealed by GRACE, Geophys. Res. Lett., 36, L19503, doi:10.1029/2009GL040222

Time to Defend Science

I have set up a petition so those who object to the traducing of climate science can make their voices heard. I hope even opponents of the mainstream position will sign, because the issue is not whether the science is correct or not, but whether science should be tested by weighing evidence against theories, or by personal attack on scientists.

Even The Guardian, a paper that usually breaks from the herd and attempts to report matters like this accurately, has jumped on the bandwagon of attacking climate scientists personally. In this article, reprinted in the internationally distributed Guardian Weekly with the title Research red in tooth and claw journalist Fred Pearce makes numerous errors. I was particularly annoyed at this reprinting of the article, since the weekly paper has more time to review content for errors. Here is what I've written to the editor:

Fred Pearce's long article "Research red in tooth and claw" is riddled with errors and misinterpretations. First, he identifies a paper by Lars Kamel as the one referred to in stolen CRU emails because "It is the only one published on that topic in the journal that year" then goes on to explain how the paper was never published. Either it was published, or it wasn't. Second, he goes on at great length about how CRU's temperature analysis has not been recreated by anyone else, and cannot be because of lack of access to the data. While I have problems with the whole concept of lack of access to data, this is denialist spin. NASA's Goddard Institute for Space Studies has independently constructed a temperature record using mostly the same data sources, and all of its data is public, and there are other independent temperature records against which CRU's can be tested. Pearce's understanding of peer review is also confused. There is nothing improper in asking other academics for inputs into reviewing a paper, and this happens very widely. Nowhere does Pearce present evidence that confidences were breached.

As Pearce could easily have discovered had he done the job he's evidently being paid to do, despite Jones's threat to keep junk papers out of the IPCC, they are in fact cited as references. The "MM" paper referred to is unlikely to be the McKitrich and Michaels paper on urban heat islands because this was published in 2007, 3 years after email Pearce quotes. The paper concerned is more likely to be that by McIntyre and McKitrick of 2003 (also rubbish), which is in fact cited in IPCC reports.

In one of Pearce's most serious blunders, he fails to report the fact that half of the editorial board of Climate Research including the newly-appointed editor in chief resigned over the journal's lapse in standards at the hands of De Freitas.

Pearce says the fact that Jones was new to the IPCC process was no excuse for errors of judgement. How new is Pearce to journalism?

PS: has Rupert Murdoch bought The Guardian?

There is a deep problem here when a usually trusted news source starts behaving in this way. Science is traditionally conducted through the research literature for a good reason. Unqualified people can easily make mistakes when assessing a complex field. The hard thing is translating research into policy. Human society does not on the whole do that very well, and I am not proposing alternatives here. What I do however object to in the strongest terms is traducing science as a whole and vicious often ill-informed personal attacks on scientists.

If you agree, sign the petition.

Of Drama Queens and Climate Science

Yet another bunch of anti-science letters in The Australia, this time in response to an article reporting the UK's chief scientist as saying climate scientists are prone to dramatise claims.


It suits the tabloid press (including those who disguise this tendency with a broadsheet layout) to frame issues in absolutes and set up crazy debates. Anything any scientist says that sounds the vaguest bit extreme or contrary to known science gets blown out of proportion, and the 99.9% of scientific work that doesn't fit this model is ignored.

Try reading the scientific literature using Google Scholar instead of regular Google as your search engine. You'll be amazed to find the vast majority of accusations against climate scientists (here for example the claim that they underplay uncertainties) are totally unfounded. Try however to get an article into a newspaper that tells it the way it is rather than setting it up as a screaming match between drama queens and you will get nowhere.

I stopped buying newspapers that do this and only read them where I can find them for free (online, in coffee shops etc.). If more people did this they would get the message.

It's hard to get a real debate going in the online comments so I will repeat some of my points here.

Peter: your claim that the raw data is "destroyed and manipulated" is rubbish. Most of the raw data is freely available. The drama queen argument here is that if a tiny fraction of the data used by one research group isn't available then all of it isn't. NASA for example makes ALL their climate data and their computer code available (see here for theirs among others). Enough data has been available for years for any serious scientist wanting to undo the mainstream theory to do so. Instead, we get vicious personal attacks, theft of email and political arguments.

SW1: your claim that further flaws will come to light is not only plausible but almost certain, but so what? Published science is riddled with errors. A researcher develops a new theoretically superior instrument, and in the rush to get published, makes mistakes in calibration. A research group finds a new angle on a problem and in their enthusiasm at finding something exciting, miss an obvious error. Peer review is a filter but not a perfect one, and this kind of thing can slip through. Sometimes the reviewers are lazy, or have a predisposition to accept the paper's findings. That's why scientists check on each other. Let's take as an example the 2009 paper by Lindzen and Choi that purported to show a much lower climate sensitivity to CO₂ increases than the accepted range of 1.5-4.5°C. This paper was trumpeted over the blogosphere as yet another nail in the coffin of anthropogenic global warming. Now various analyses of their paper are showing that their approach was flawed, including one by Roy Spencer, who generally disagrees with the mainstream figure on climate sensitivity. There is at least one published response that shows the paper to contain serious errors. The drama queen version of events: Lindzen once again strikes a fatal blow against science, and the "corrections" can safely be ignored.

Another example is the claim that the oceans are cooling. NASA has an interesting story on their web site of how the science in that case unfolded. One of their researchers, Josh Willis, published results using a new technology, Argo floats, that showed the oceans were cooling. While he described this as a "speed bump" rather than a slowdown in warming, the blogosphere went gaga and many people still quote this result. What actually happened was some of the floats were under-reporting temperature, while the older technology used for older measurements was over-reporting temperature, and these two effects combined to create an appearance of cooling. Any cooling would contradict a range of other kinds of evidence, so had these results held up, it would have been a major challenge to the science. Instead, the problem turned out to be in the data. Again, nothing too unusual. But the drama queen interpretation is Willis overthrew the entire theory, and the conspirators worked hard in the background to reinstate it.

My focus here has been on attacks on the mainstream but of course there are people out there who make extreme claims about the risks of climate change. These people do not represent the scientific community, who as a whole are pretty loath to make extreme claims without strong evidence. But these stories too get the headlines.

The bottom line? Google Scholar is your friend. Whenever something implausibly extreme or contrary to accepted knowledge appears, go to the scientific literature. Preferably after waiting 6 months for the dust to settle.