Thursday, March 29, 2007

Prospect - a response

David Whitehouse, once a science reporter for the BBC, has responded to my denunciation of ‘climate sceptics’ in Prospect. Here are his comments – I don’t find them very compelling, but you can make up your own mind:

"Philip Ball veers into inconsistent personal opinion in the global warming debate. He says the latest IPCC report comes as close to blaming humans for global warming as scientists are likely to. True, its summary replaced “likely to be caused by humans” with “very likely”, but that is hardly a great stride towards certainty, especially when deeper in the report is says that it is only “likely” that current global temperatures are the highest they’ve been in the past 1,300 years.
As for “sceptics” saying false and silly things, Ball should look to the alarmist reports about global warming so common in the media. These “climate extremists” are obviously saying false, silly things, as even scientists who adhere to the consensus have begun to notice. And it’s data, not economics, that will be the future battleground. The current period of warming began in 1975, yet the very data the IPCC uses shows that since 2002 there has been no upward trend. If this trend does not re-establish itself with force, and soon, we will shortly be able to judge who has been silliest.”

The first point kind of defeats itself: by implying that the IPCC’s move towards a stronger statement is rather modest, Whitehouse illustrates my point, which is that the IPCC is (rightly) inherently conservative (see my last entry below) and so this is about as committed a position as we could expect to get. If they had jumped ahead of the science and claimed 100% certainty, you can guess who’d be the first to criticize them for it.

Then Whitehouse points out that climate extremists say silly and false things too. Indeed they do. The Royal Society, who Whitehouse has falsely accused of trying to suppress research that casts doubt on anthropogenic climate change, has spent a lot of time and energy criticizing groups who do that, such as Greenpeace. I condemn climate alarmism too. Yes, the Independent has been guilty of that – and is balanced out by the scepticism of the right-wing press, such as the Daily Telegraph. But Whitehouse’s point seems to be essentially that the sceptics’ false and silly statements are justified by those of their opponents. I suspect that philosophers have got a name for this piece of sophistry. Personally, I would rather than everyone try harder not to say false and silly things.

I don’t know whether Whitehouse’s next comment, about the ‘current warming’ beginning in 1975 is false and/or silly, or just misinformed. But if it’s the latter, that would be surprising for a science journalist. There was a warming trend throughout the 20th century, which was interrupted between 1940 and 1970. It has been well established that this interruption is reproduced in climate models that take account of the changes in atmospheric aerosol levels (caused by human activities): aerosols, which have a cooling influence, temporarily masked the warming. So the warming due to CO2 was continuous for at least a century, but was modified for part of that time by aerosols. The trend since 1975 was thus not the start of anything new. This is not obscure knowledge, and one can only wonder at why sceptics continue to suppress it.

As for the comment that the warming has levelled off since 2002: well, the sceptics make a huge deal of how variable the climate system is when they want to imply that the current warming may be just a natural fluctuation, but clearly they like to cherry-pick their variations. They argue that the variability is too great to see a trend reliably over many decades, but now here’s Whitehouse arguing for a ‘trend’ over a few years. Just look at the graphs and tell me whether the period from 2002 to 2006 can possibly be attributed to variability or to a change in trend. Can you judge? As any climatologist will tell you, it is utterly meaningless to judge such things on the basis of a few years. Equally, we can’t attach too much significance, in terms of assessing trends, to the fact that the last Northern Hemisphere winter was the warmest since records began. (Did Whitehouse forget to mention that?) But that fact hardly suggests that we’re starting to see the end of global warming.

“Who has been silliest” – OK, this is a rhetorical flourish, but writers should pick their rhetoric carefully. If the current consensus on a warming trend generated by human activity proves to be wrong, or counteracted by some unforeseen negative feedback, that will not make the scientists silly. It will mean simply that they formed the best judgement based on the data available. Yes, there are other possible explanations, but at this point none of them looks anywhere near as compelling, or even likely.

My real point is that it would be refreshing if, just once, a climate sceptic came up with an argument that gave me pause and forced me to go and look at the literature and see if it was right. But their arguments are always so easily refuted with information that I can take straight off the very narrow shelves of my knowledge about climate change. That’s the tiresome thing. I suppose this may sound immodest, but truly my intention is just the opposite: if I, as a jobbing science writer, can so readily see why these arguments are wrong or why they omit crucial factors – or at the very least, why the climate community would reject them – then why do these sceptics, all of them smart people, not see this too? I am trying hard to resist the suspicion of intellectual dishonesty; but how much resistance am I expected to sustain?

3 comments:

Dr David Whitehouse said...

Dear Phillip,

Interesting points. I thought your 'Report from the Lab' in Prospect magazine was rather extremist and unscientific and I suggest you post that article on your blog.

There is much wisdom in what you say though I don't agree on some points.

I know that in many respects the IPCC is a conservative organisation (though I worry about the influence of the various politicians in producing the consensus statement) but it is no good saying that we should not read anything into their rather modest shift of opinion. You say it yourself. If they had expressed 100% certainty they would have jumped ahead of the science. In fact they reflect my own view that human-induced GW is a good working hypothesis at about the 90% level of confidence. This clearly shows that the science is not as settled as it ever could be or perhaps will be.

You connect two unconnected points when linking my criticism of the way the Royal Society was handling the debate with some people on both sides saying extremist things. I don't think that one side's extremist comments are justified or in any way counterballanced by the other side's extremist comments. I think some people unfairly categorise any research that does not support the consensus as extremist and wrongly pit it against those who wind up their computer models to produce extreme results as if they were somehow counterballancing and the truth lies somewehere inbetween.

True, some computer models explain the 1945 -75 dip in terms of shielding due to aerosols but I'm always skeptical about such models particularly when applied with hindsight. Also looking at the IPCC data the world started warming around mid 19th century which might be consistent with the IPCC's statements that human effects are only part of the story. I'm not convinced at all that increasing CO2 levels in 1850 were responsible for that. It's interesting that the gradient seems, within the errors, constant.

Your point about cherry picking is irrelevant. If the world is warming look at the temperature data not opinion or consensus or even what journalists say, it's the only cherry worth investigating. (I'm not sure you are right when you say that all sceptics argue that the variability is too great to see a trend reliably over many decades I think the temperature increase seen since 1850 or so contracicts this).

It does seem that when the global temperature increases it supports the case but when it stutters - for whatever reason - it still supports that view. My point is that the data in the past few years is interesting but, whatever it is - scatter, El Nino, La Nina, aerosols, sun-influenced, cosmic-ray mediated, etc the upward drift in temperatures must reestablish itself (or else let me guess - a model will be found to account for it) if the science is what the IPCC believes it is. It is too soon to say that GW is at an end but we must keep an eye on the data and not make assumptions.

Finally, when talking about silly comments and illogical extremist positions I wasn't refering soley to scientists.

Anyway, sorry for the long post. Congratulations on the interesting blog.

Philip Ball said...

Dear David,
Thanks for your comments. I did post the Prospect article here - see entry for 9 Feb.

I'm glad to see that we're not as divergent in our views as I'd imagined. Certainly, if it's the case that, as you say, "some people unfairly categorise any research that does not support the consensus as extremist", I'd agree that this is wrong. But I'm not sure who these people are. I've not heard Lindzen or Svensmark, say, called extremist by other scientists. There are, of course, certainly "climate change extremists" who are as misconceived as the climate sceptics.

You say you're sceptical about the aerosol explanation of the 1940-70 cooling. Fair enough, but without knowing why, I can't comment. It's simply what the models show. If you think that the models were somehow rigged to produce this result, and then allowed past peer review because that suited the political position of the reviewers, that does sound a little too much like a conspiracy theory to me. And aren't you being a little inconsistent yourself in claiming in your Prospect letter that the current warming trend began in 1975 but now saying it began in the mid-19th C?

I agree that in the end we must of course look to the data. I simply found it ironic that, when so often climate sceptics insist on natural variability as a reason to be hesitant about seeing a human influence, you didn't seem to want to think about variability on a 4-yr timescale, where it REALLY is ill-advised to claim any kind of trend. I'm glad to see that at least, after a warming trend of over 100 years (given the aerosol caveat above), you agree that it's too early to say whether the levelling seen since 2002 is the "end". But yes, of course you're right that we need to remain vigilant about the possibility of other explanations for global warming, even if these seem unlikely at present.

Midority said...

I bounced over here whilst checking to see if Dr David Whitehouse is in fact who he says he is (identity theft being a common digital-age phenomena), and whether or not what he seems to be saying is in fact truly what he believes and not just gross misquotations. But it seems that he is who he is, and means what he says.

Unfortunately.

Even more unfortunate is that what he's saying is clearly wrong, and the doctor is obviously able to rest on his laurels obtained by reporting for the BBC and feels he has no need to provide any kind of references to back up his wild statements of disinformation, misinformation and grey truths (if not outright lies).

I'm sure he is a very busy man, however one thing is clear, Dr Whitehouse should do a little further reading before he shoots off articles such as his "Has global warming stopped?" of the New Statesman. (http://www.newstatesman.com/200712190004)

Here are a couple of quotes WITH references that he would do well to peruse (including from his very own BBC):

"Summer melting this year reduced the [Arctic] ice cover to 4.13 million sq km, the smallest ever extent in modern times.

The Intergovernmental Panel on Climate Change (IPCC), the UN-led body which assesses the state of the Earth's climate system, uses an averaged group of models to forecast ice loss in the Arctic.

But it is has become apparent in recent years that the real, observed rate of summer ice melting is now starting to run well ahead of the models.

The minimum ice extent reached in September 2007 shattered the previous record for ice withdrawal set in 2005, of 5.32 million square km.

The long-term average minimum, based on data from 1979 to 2000, is 6.74 million square km. In comparison, 2007 was lower by 2.61 million square km, an area approximately equal to the size of Alaska and Texas combined, or the size of 10 United Kingdoms."


http://news.bbc.co.uk/2/hi/science/nature/7139797.stm

"Greenland's glaciers are sliding towards the sea much faster than previously believed, scientists have told a conference in St Louis, US.

It was thought the entire Greenland ice sheet could melt in about 1,000 years, but the latest evidence suggests that could happen much sooner.

It implies that sea levels will rise a great deal faster as well.

Details of the study, by Nasa and University of Kansas researchers, are also reported in the journal Science.

The comprehensive analysis found that the amount of ice dumped into the Atlantic Ocean has doubled in the last five years.

If the Greenland ice sheet melted completely, it would raise global sea levels by about 7m.

Greenland's contribution to global sea level rise today is two to three times greater than it was in 1996."


http://news.bbc.co.uk/2/hi/science/nature/4720536.stm

"NOAA: 2007 a Top Ten Warm Year for U.S. and Globe

The year 2007 is on pace to become one of the 10 warmest years for the contiguous U.S., since national records began in 1895, according to preliminary data from NOAA’s National Climatic Data Center in Asheville, N.C. The year was marked by exceptional drought in the U.S. Southeast and the West, which helped fuel another extremely active wildfire season. The year also brought outbreaks of cold air, and killer heat waves and floods.

Meanwhile, the global surface temperature for 2007 is expected to be fifth warmest since records began in 1880. Preliminary data will be updated in early January to reflect the final three weeks of December and is not considered final until a full analysis is complete next spring.

Including 2007, seven of the eight warmest years on record have occurred since 2001 and the 10 warmest years have all occurred since 1997. The global average surface temperature has risen between 0.6°C and 0.7°C since the start of the twentieth century, and the rate of increase since 1976 has been approximately three times faster than the century-scale trend."


http://www.noaanews.noaa.gov/stories2007/20071213_climateupdate.html


NOTE: Global figures are AVERAGE figures. The southern hemisphere has experienced far less warming that the northern, which makes the northern hemispheres swings all the more extreme when taking this into account.

I don't need strong words to refute any silliness, just facts. The above are all referenced facts.

Please, Dr Whitehouse, let us see the sources of your so-called "facts" so we can verify their authenticity.