It has been a bad-make that dreadful-few weeks for what used to be called the "settled science" of global warming, and especially for the U.N. Intergovernmental Panel on Climate Change that is supposed to be its gold standard.
First it turns out that the Himalayan glaciers are not going to melt anytime soon, notwithstanding dire U.N. predictions. Next came news that an IPCC claim that global warming could destroy 40% of the Amazon was based on a report by an environmental pressure group. Other IPCC sources of scholarly note have included a mountaineering magazine and a student paper.
Since the climategate email story broke in November, the standard defense is that while the scandal may have revealed some all-too-human behavior by a handful of leading climatologists, it made no difference to the underlying science. We think the science is still disputable. But there's no doubt that climategate has spurred at least some reporters to scrutinize the IPCC's headline-grabbing claims in a way they had rarely done previously.
Take the rain forest claim. In its 2007 report, the IPCC wrote that "up to 40% of the Amazonian forests could react drastically to even a slight reduction in precipitation; this means that the tropical vegetation, hydrology and climate system in South America could change very rapidly to another steady state."
But as Jonathan Leake of London's Sunday Times reported last month, those claims were based on a report from the World Wildlife Fund, which in turn had fundamentally misrepresented a study in the journal Nature. The Nature study, Mr. Leake writes, "did not assess rainfall but in fact looked at the impact on the forest of human activity such as logging and burning."
The IPCC has relied on World Wildlife Fund studies regarding the "transformation of natural coastal areas," the "destruction of more mangroves," "glacial lake outbursts causing mudflows and avalanches," changes in the ecosystem of the "Mesoamerican reef," and so on. The Wildlife Fund is a green lobby that believes in global warming, and its "research" reflects its advocacy, not the scientific method.
The IPCC has also cited a study by British climatologist Nigel Arnell claiming that global warming could deplete water resources for as many as 4.5 billion people by the year 2085. But as our Anne Jolis reported in our European edition, the IPCC neglected to include Mr. Arnell's corollary finding, which is that global warming could also increase water resources for as many as six billion people.
The IPCC report made aggressive claims that "extreme weather-related events" had led to "rapidly rising costs." Never mind that the link between global warming and storms like Hurricane Katrina remains tenuous at best. More astonishing (or, maybe, not so astonishing) is that the IPCC again based its assertion on a single study that was not peer-reviewed. In fact, nobody can reliably establish a quantifiable connection between global warming and increased disaster-related costs. In Holland, there's even a minor uproar over the report's claim that 55% of the country is below sea level. It's 26%.
Meanwhile, one of the scientists at the center of the climategate fiasco has called into question other issues that the climate lobby has claimed are indisputable. Phil Jones, who stepped down as head of the University of East Anglia's Climatic Research Unit amid the climate email scandal, told the BBC that the world may well have been warmer during medieval times than it is now.
This raises doubts about how much our current warming is man-made as opposed to merely another of the natural climate shifts that have taken place over the centuries. Mr. Jones also told the BBC there has been no "statistically significant" warming over the past 15 years, though he considers this to be temporary. *** All of this matters because the IPCC has been advertised as the last and definitive word on climate science. Its reports are the basis on which Al Gore, President Obama and others have claimed that climate ruin is inevitable unless the world reorganizes its economies with huge new taxes on carbon. Now we are discovering the U.N. reports are sloppy political documents intended to drive the climate lobby's regulatory agenda.
The lesson of climategate and now the IPCC's shoddy sourcing is that the claims of the global warming lobby need far more rigorous scrutiny.