Monday, January 28, 2008

Say It Ain't So, al-Goracle!

Some would think that they'd fall into line, eh. But Canadian scientists - that is, real scientists, eh, have hosed one of the linchpins of al-Gore's 'global warming' junk science. Doing so at the site where al-Gore says there's irrefutable, on-the-ground evidence that Bushchimphitler 'global warming' wreaked havoc in 2005 makes it ever so sweet.

Physicist questions climate change finding

No evidence in Canadian skies to back U.S. theory of jet condensation trails, York U. professor says

NEW ORLEANS – A York University professor has ignited a controversy by challenging a supposed prime example of man-made climate change – that jet condensation trails, know as contrails, act like clouds, cooling the Earth during the day and keeping it warmer at night.

Physicist William van Wijngaarden says he found no evidence to support this climate effect in Canadian temperature records for the contrail-free days immediately after the 9/11 terrorist attacks.

That contrasts with a 2002 study by U.S. researchers that concluded the temperature spread between day and night over the lower 48 states increased by 1.5C over long-term averages between Sept. 11 and 14 in 2001, when commercial air flights were mostly grounded over North America.

Those results initially reinforced theories that thin jet contrails may spread out over large areas for days, becoming invisible from the ground but still blocking infrared radiation, or heat.

Their absence would mean lower temperatures at night as more heat escaped the Earth. It could also mean higher daytime temperatures since the contrails weren't there to reduce the sun's rays.

This double whammy would increase the span between daytime highs and nighttime lows, called the diurnal temperature range.

Heralded as evidence from a "natural laboratory," the U.S. findings after 9/11 have been widely quoted as demonstrating short-term human impact on climate, since the birth of jet travel in the 1950s, as opposed to the longer buildup of greenhouse gases from burning fossil fuels.

"There's been a lot of groupthink going on about this," Wijngaarden said in an interview in New Orleans at the annual meeting of the American Meteorological Society.

The York researcher said he decided to double-check the U.S. findings because the claimed temperature rise was so large, almost equal to the global average temperature increase from greenhouse warming.

"If it was that big, then I ought to have been able to see it in Canada," he said.

But when he examined the spread between day and night temperatures from 112 weather stations across Canada for Sept. 8 to 17 in 2001, there wasn't a spike during the no-fly period.

In Canada, commercial flights were grounded entirely for 48 hours after the terrorist attacks and were about a third of normal levels for the next 24 hours.

Yet the diurnal temperature range for September 2001 across Canada fell well within the long-term average from 1977 to 2005.

The absence of any contrail effect held true even for the 34 weather stations in Canada below the 50-degree latitude, where jet flights are normally most intense.

Instead, Wijngaarden found the temperature range at stations across southern Canada both increased and decreased in the contrail-free days after the post 9-11

"The American researchers need to look a bit harder at the original data," Wijngaarden said.

The lead researcher on the original U.S. study told the Star yesterday that the negative results from Canada don't necessarily undermine his group's findings.

"It's possible that Canada simply doesn't have a high enough density of jet traffic for contrails to make any difference," said David Travis, a geography professor at the University of Wisconsin in Whitewater.

But Travis said he had not realized Pearson Airport has been ranked 20th busiest airport in the world measured by takeoffs and landings.

Wijngaarden travelled in person to New Orleans to explain his controversial findings at the largest gathering of meteorologists and climate experts in the world.

"If I wasn't here, people might say I was chickening out," he said.

al-Gore was busy in his office doing paperwork and was unavailable for comment.

Previously: Wait a minute, I thought the science was settled?

Also at A Tangled Web

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