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.

Dealing with climate change

We have no option but to deal with climate change.

Either we deal with it or it will deal with us.

There is no serious challenge to the science behind climate change. The whole basis for the denial movement is not attacking the science, but attacking the scientists. Look for a real scientific paper attacking the science. There is a very small number of these, all of which have been debunked. Most other material is on blogs and the opinion papers of the mass media, replete with the language of personal attack. Climate scientists are "alarmists", "warmists", "catastrophists", and any other number of made-up appellations.

As with the tobacco and HIV denial movements, personal attack does not prevent the ultimate harm that denial of the facts causes.

Unlike tobacco and HIV, we are not talking about something that will ruin the lives of a few million people if not dealt with expeditiously. Rapid climate change is causing a rapid acceleration of extinction rates. The rapid depletion of the Himalayan glaciers threatens the food supply of a half a billion people: melt water from these glaciers feed major river systems of both India and China. And reduced agricultural output is likely to be worst in poorer countries.

Talk therefore of whether an emissions trading scheme should be contemplated in the absence of any serious alternative is crazy. The Australian government's scheme falls far short of any reasonable solution, but their main opposition is opposing it without offering an alternative.

Given that, how will climate change deal with Australia?

There are two possibilities: Australia's inability to face up to the problem could be a worldwide phenomenon, in which case we face a period of growing environmental disaster: death of the Great Barrier Reef, collapse of food supply in India and China, famine in Africa. If on the other hand the rest of the world gets its act together, Australia as the world's biggest coal exporter and the country with the highest per capita CO₂ emissions will be left high and dry, and as uncompetitive as a country that did not foresee the trend away from horse-based transport a century ago.