Last week, a research team at Berkeley led by a former climate change skeptic released a study of global temperatures that intended to set the record straight on controversial data collected by the East Anglia Project, NASA, and other organizations that have acted as advocates for action based on anthropogenic global warming. Professor Richard Muller put together a graph of the data that supposedly showed warming from 1800 (roughly the beginning of the Industrial Era in Europe) through 1975, and then a steeper rise in temperatures that appears unstopped. When this data was released, newspapers and other media proclaimed it the end of AGW skepticism and demanded capitulation from the “deniers.”
This led to an interesting e-mail exchange between myself and one of my blogging friends, whom I won’t name because (a) the e-mails weren’t really intended for publication, and (b) he’s a good guy who is passionate about doing what’s right. I got an e-mail from him challenging me on this point, saying the correlation between rising temperatures and mass release of CO2 was undeniable. I explained to him that AGW skepticism doesn’t rest on the notion that global temperatures aren’t rising, but that the AGW crowd has yet to show causation between CO2 release and actual warming. He replied that correlation was enough to prompt action, but that’s neither scientific or wise. Correlation only shows that two trends parallel each other; if one isn’t the cause of the other, then “solutions” designed to change one trend won’t impact the other anyway — and it will waste time, money, and perhaps lives while the perceived problem continues unabated.
As it turns out, the correlation isn’t exactly equal, either. A closer look at the data and a Daily Mail interview with one of Muller’s team shows that the chart hides the fact that no warming has occurred in the last 11 years, as has been repeatedly pointed out:
Prof Judith Curry, who chairs the Department of Earth and Atmospheric Sciences at America’s prestigious Georgia Institute of Technology, said that Prof Muller’s claim that he has proven global warming sceptics wrong was also a ‘huge mistake’, with no scientific basis.
Prof Curry is a distinguished climate researcher with more than 30 years experience and the second named co-author of the BEST project’s four research papers.
Her comments, in an exclusive interview with The Mail on Sunday, seem certain to ignite a furious academic row. She said this affair had to be compared to the notorious ‘Climategate’ scandal two years ago. …
In fact, Prof Curry said, the project’s research data show there has been no increase in world temperatures since the end of the Nineties – a fact confirmed by a new analysis that The Mail on Sunday has obtained.
‘There is no scientific basis for saying that warming hasn’t stopped,’ she said. ‘To say that there is detracts from the credibility of the data, which is very unfortunate.’
Let’s take a look at Muller’s chart, and then compare it to the chart for the last 13 years — which the Daily Mail labels an “inconvenient truth”:
First, let’s look at the top chart. A closer reading of the top chart shows that, relative to the 1950-1980 average baseline BEST uses, temperatures didn’t actually warm at all until sometime during the Great Depression, so the entire first century of the Industrial Era apparently had no impact — in a period where the dirtiest of mass energy production processes was in widest use (coal). Temperatures then started to slowly rise during an era of significantly reduced industrial output, thanks to a lengthy economic depression that gripped the entire world. What we end up with is a 30-year spike that also includes a few years of reduced industrial output, starting in the stagnating 1970s where oil production also got restricted thanks to onerous government policies and trade wars.
In climate terms, a 30-year spike is as significant as a surprisingly warm afternoon in late October. Man, I wish we were going to have one of those today.
But then look what happens in the past 11 years in the bottom chart. Despite the fact that the world’s nations continue to spew CO2 with no significant decline (except perhaps in the Great Recession period of 2008-9), the temperature record is remarkably stable. In fact, it looks similar to the period between 1945 and 1970 on the top chart. If global temperature increases really correlated directly to CO2 emissions, we wouldn’t see this at all; we’d see ever-escalating rates of increase in global temperatures, which is exactly what the AGW climate models predicted at the turn of the century. They were proven wrong.
And in fact, Curry explains that the failure of those models finally has some scientists going back to the drawing board:
‘This is nowhere near what the climate models were predicting,’ Prof Curry said. ‘Whatever it is that’s going on here, it doesn’t look like it’s being dominated by CO2.’ …
‘Of course this isn’t the end of scepticism,’ she said. ‘To say that is the biggest mistake he [Prof Muller] has made. When I saw he was saying that I just thought, “Oh my God”.’
In fact, she added, in the wake of the unexpected global warming standstill, many climate scientists who had previously rejected sceptics’ arguments were now taking them much more seriously.
They were finally addressing questions such as the influence of clouds, natural temperature cycles and solar radiation – as they should have done, she said, a long time ago.
And what of Muller? When confronted by the Daily Mail about the data from the past 11 years, he denied that temperatures had plateaued, and then admitted that the data shows exactly that:
Yesterday Prof Muller insisted that neither his claims that there has not been a standstill, nor the graph, were misleading because the project had made its raw data available on its website, enabling others to draw their own graphs.
However, he admitted it was true that the BEST data suggested that world temperatures have not risen for about 13 years. But in his view, this might not be ‘statistically significant’, although, he added, it was equally possible that it was – a statement which left other scientists mystified.
‘I am baffled as to what he’s trying to do,’ Prof Curry said.
Even perfect correlation doesn’t prove causation, and this is far from being perfect correlation. AGW scientists have still failed to prove that CO2 is responsible for the moderate rise in temperatures, nor have they proven their hypothesis that the rise is irreversible, or even bad. As I pointed out to my friend, Greenland hosted a farming community for over 200 years before getting swallowed in ice in a global-cooling period that helped spread disease, death, and starvation throughout Europe. If Greenland once again becomes farmland, then we might be entering a somewhat more remarkable climate period in human history, but until then this is more properly referred to as weather.
BEST did help settle the temperature record, an important step in climate research and a necessary corrective to the manipulations discovered in Climategate. But they didn’t “prove” anthropogenic global warming or any kind of causation, and even their correlation proves rather weak.