Gee, has it been a week since The Mail on Sunday posted a climate change denial article by David Rose? Time flies.
Last week, Rose wrote an error-laden article about global warming, which was immediately debunked by many people. This, however, has not stopped Rose from continuing in that vein; on Sunday he wrote another article where he just plows on through, piling one misleading claim on top of the last.
I won't try your patience (or mine for that matter) listing every error in it, but there are two that need pointing out, especially since one is the basis of his entire article.
His major claim is that a new report soon to be released by the Intergovernmental Panel on Climate Change (IPCC; leaked copies of these reports make it out fairly often) says that the world is warming much more slowly than previously measured:
Yet the leaked report makes the extraordinary concession that the world has been warming at only just over half the rate claimed by the IPCC in its last assessment, published in 2007.
Back then, it said that the planet was warming at a rate of 0.2C every decade – a figure it claimed was in line with the forecasts made by computer climate models.
But the new report says the true figure since 1951 has been only 0.12C per decade – a rate far below even the lowest computer prediction.
To be polite, I'll just say these statements are a huge misinterpretation of reality.
I went to the Assessment Report 4 (AR4), the document from 2007 he’s talking about. On page 12 of the Summary for Policymakers, it says this:
Since IPCC’s ﬁrst report in 1990, assessed projections have suggested global average temperature increases between about 0.15°C and 0.3°C per decade for 1990 to 2005. This can now be compared with observed values of about 0.2°C per decade, strengthening confidence in near-term projections.
That’s where Rose gets that 0.2°C number. Ah, but note the time range: 1990-2005. That’s a sixteen year time span, and a recent one.
If you look at page 5 of that same report, you’ll also see this statement [emphasis mine]:
The linear warming trend over the last 50 years (0.13°C [0.10°C to 0.16°C] per decade) is nearly twice that for the last 100 years.
Note the time range here: It’s actually over 50 years, and starts far earlier than the time range quoted for the 0.2° rise per decade. We know the Earth is warming faster now than it was a century (or five decades ago), so comparing a recent 16-year span to one that’s 50 years long and much older is grossly inappropriate. It’s apples to oranges. And in the second statement it actually says flat out that the more recent 50 years have warmed far faster than the 50 before them.
If the new report Rose is talking about says the increase since 1951 is 0.12°C per decade, then it’s off by only 8 percent from the earlier measurement of 0.13°. That sounds pretty dang accurate to me.
Myles to Go
In his article, Rose quotes climate scientist Myles Allen:
One of the report’s own authors, Professor Myles Allen, the director of Oxford University’s Climate Research Network, last night said this should be the last IPCC assessment – accusing its cumbersome production process of ‘misrepresenting how science works’.
I have read some of Professor Allen’s writing before, and this statement surprised me. However, I also know Rose has a habit of getting things like this very wrong (like here and here and here and here), so I contacted Allen and asked him about the quote. He told me,
I did not talk to David Rose about the content of the IPCC report.
I did not say this should be the last IPCC report, I said that in my view producing a massive volume once every six years has become counterproductive. […] For what it is worth, I would favour much shorter annual update reports, plus special reports on specific issues...
Clearly, what Rose quotes Allen as saying, and what Allen actually said, are very different things.
It gets worse. Allen never said the “cumbersome process” of the report is misrepresenting how science works. Allen told me that he dislikes it when people either hold the report as infallible or attack it on nitpicky levels for minor errors. Those are the ones, he says, who misrepresent how science works.
Allen felt he had to correct Rose, so he left a comment in the Mail article:
Since I am quoted in this article, I think it is important to point out that the IPCC in 2007 said that the “warming trend over the last 50 years was 0.13 degrees C per decade.” Neither the IPCC in 2007 nor the current crop of climate models ever suggested that the world has been, or should have been, warming at 0.2 degrees per decade since 1951 -- a full degree of warming between the 1950s and 2000s? So the headline should have been “Global warming is just 92% of what we said it was”, on an apples-for-apples comparison.
[I cannot link to individual comments, but this was left on Sep. 15, 2013 at 06:41 UK time (05:41 UTC).]
Also, Allen told me, “I have asked him three times whether he understood when writing the article that the 0.2 degrees per decade figure in AR4 did not refer to the period since 1951, and he has declined to say.”
The Devil and the Deep Blue Sea
I can't resist. I have to point out one more thing, because it's become such a common denier claim it really needs some disinfectant sprayed on it. About the IPCC report:
They recognise the global warming ‘pause’ first reported by The Mail on Sunday last year is real – and concede that their computer models did not predict it. But they cannot explain why world average temperatures have not shown any statistically significant increase since 1997.
Actually, yes, it can be explained. The extra heat is going into the deep oceans, and not the surface of the land. This is actually pretty well understood, as Skeptical Science points out (and check the links listed there for lots more info as well). This whole claim that the Earth hasn’t warmed over the past 16 years is utter bilge. Surface temperatures over land haven’t gone up much, but that’s not the only or even the best way to measure the amount of warming. There’s a lot of planet out there that isn’t land. Ignoring the oceans is just plain wrong.
And don’t forget that nine of the last ten years have been the warmest on record.
The Fifth Assessment Report from the IPCC is scheduled to be released next year; various draft versions get leaked all the time (which is why I agree with Allen that a more streamlined reporting system with shorter assessments makes sense). But as we near the time of the final report’s public release, expect to see louder and more desperate claims from the deny-o-sphere.