Wednesday, February 17, 2010

More IPCC Headaches: how reliable is the hurricane data?

More trouble looms for the IPCC. The body may need to revise statements made in its Fourth Assessment Report on hurricanes and global warming. A statistical analysis of the raw data shows that the claims that global hurricane activity has increased cannot be supported.

Les Hatton once fixed weather models at the Met Office. Having studied Maths at Cambridge, he completed his PhD as metereologist: his PhD was the study of tornadoes and waterspouts. He’s a fellow of the Royal Meterological Society, currently teaches at the University of Kingston, and is well known in the software engineering community – his studies include critical systems analysis.

Hatton has released what he describes as an ‘A-level’ statistical analysis, which tests six IPCC statements against raw data from the National Oceanic and Atmospheric (NOAA) Administration. He’s published all the raw data and invites criticism, but warns he is neither “a warmist nor a denialist”, but a scientist.

(The number of intense, category 3-5 hurricanes has nearly doubled since 1970, but it's difficult for climatologists to connect the dots and say that climate change is resulting in MORE hurricanes. In the end it may be that we're loading the dice, warmer ocean water increasing the potential for severe hurricanes, but making the claim that man-made warming is producing more hurricanes can't - yet - be supported by the data). The complete article is here.

Tuesday, February 16, 2010

Washington's snowstorms, brought to you by global warming

RIPTON, VERMONT -- You want to hear my winter weather story? No, really, I know you do.

The cross-country ski race I've been training for, set for today high in the Green Mountains: cancelled, lack of snow.

Meanwhile, across the continent, backhoes and helicopters are moving snow down British Columbia's Cypress Mountain in an attempt to cover the Olympic ski courses, and technicians are burying cooling pipes beneath the moguls to keep them from melting. Some climate-conscious jokers put out a video pushing the sport of "bobwheeling" for future snow-challenged Olympiads.

And apparently there was some snowfall in the greater Washington area last week.

When you're trying to launch snowboarding tricks on dry ground and simultaneously shutting down the U.S. government because the snowbanks are casting shadows on the Washington Monument, something odd is going on. This isn't a good old-fashioned winter for the District of Columbia, not unless you're remembering the last ice age. And it doesn't disprove global warming, despite Sen. Jim De Mint's cheerful tweet: "It's going to keep snowing until Al Gore cries 'uncle.' "

Instead, the weird and disruptive weather patterns around the world are pretty much exactly what you'd expect as the planet warms. Here's how it works:

The complete blog post is here.

Scientists dispute climate skeptic's claim that US weather data is useless

Some amateur climate sceptics have said weather stations across the US are poorly located and thus cannot be relied on. Photograph: Junos/Corbis

It appeared to have shaken the credibility of one of the most important global warming data sets in the world. A blog-inspired campaign by amateur climate sceptics seemed to show that numerous weather stations across the US were so poorly located they could not be relied upon.

But a new scientific analysis, using data from the sceptics, has shown that, if anything, the poorly located stations underestimate warming, rather than exaggerating it.

The US temperature record uses data from thousands of weather stations spread around the country. Their accuracy was called into question following a campaign by climate sceptic Anthony Watts, an ex-weatherman who runs the influential blog WattsUpWithThat.

He set up a site called for readers to post photos of poorly located weather stations, particularly in places that could be influenced by artificial heat, such as air conditioning units or car parks. The photos were compiled into a book published by the right-wing thinktank the Heartland Institute. In it, Watts wrote: "The conclusion is inescapable: The US temperature record is unreliable. And since the US record is thought to be 'the best in the world,' it follows that the global database is likely similarly compromised and unreliable."

But scientists at the National Climatic Data Centre (NCDC) in North Carolina have analysed the weather station data to see what difference poor location actually makes. Watts had ranked the stations by his estimation of the quality of their location, so Dr Matthew Menne and colleagues compared the results from high- and low-ranked stations. They described their results as "counterintuitive" – poorly located stations were actually more likely to be cooler than those in better locations. This is probably because the poorly located stations are more likely to use more up-to-date measuring equipment called Maximum-Minimum Temperature System (MMTS), which has a slight "cool" bias that is already well documented.

The complete article in the UK's Guardian newspaper is here.

The continuing climate meltdown

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 rest of the editorial in the Wall Street Journal is here.