Friday, October 26, 2007

35 Mistakes, continued

Polar bear "dying"
Gore says a scientific study shows that polar bears are being killed swimming long distances to find ice that has melted away because of “global warming.” They are not. The study, by Monnett & Gleason (2005), mentioned just four dead bears. They had died in an exceptional storm, with high winds and waves in the Beaufort Sea. The amount of sea ice in the Beaufort Sea has grown over the past 30 years. A report for the World Wide Fund for Nature shows that polar bears, which are warm-blooded, have grown in numbers where temperature has increased, and have become fewer where temperature has fallen. Polar bears evolved from brown bears 200,000 years ago, and survived the last interglacial period, when global temperature was 5 degrees Celsius warmer than the present and there was probably no Arctic ice-cap at all. The real threat to polar bears is not “global warming” but hunting. In 1940, there were just 5,000 polar bears worldwide. Now that hunting is controlled, there are 25,000. Ms. Kreider says sea-ice “was the lowest ever measured for minimum extent in 2007.” She does not say that the measurements, which are done by satellite, go back only 29 years. She does not say that the North-West Passage, a good proxy for Arctic sea-ice extent, was open to shipping in 1945, or that Amundsen passed through in a sailing vessel in 1903.

Coral reefs "bleaching"
Gore says coral reefs are “bleaching” because of “global warming.” They are not. There was some bleaching in 1998, but this was caused by the exceptional El Nino Southern Oscillation that year. Two similarly severe El Ninos over the past 250 years also caused extensive bleaching. “Global warming” was nothing to do with it.Ms. Kreider says, “The IPCC and other scientific bodies have long identified increases in ocean temperatures with the bleaching of coral reefs.” So they have: but the bleaching in 1998 occurred as a result not of “global warming” but of a rare, though not unique, severe El Nino Southern Oscillation.

100 ppmv of CO2 "melting mile-thick ice"
Gore implies that the difference of just 100 parts per million by volume in CO2 concentration between an interglacial temperature maximum and an ice-age temperature minimum causes “the difference between a nice day and having a mile of ice above your head.” It does not. Gore’s implication has the effect of overstating the mainstream consensus estimate of the effect of CO2 on temperature at least tenfold. Temperature changes by up to 12 degrees C between glacial minima and interglacial maxima, but CO2 concentration changes by no more than 100 ppmv. Gore is accordingly implying that 100 ppmv can cause a temperature increase of up to 12 degrees C. However, the consensus as expressed by the IPCC is that 100 ppmv of increased CO2 concentration, from 180 to 280 ppmv, would increase radiant energy flux in the atmosphere by 2.33 watts per square meter, or less than 1.2 degrees Celsius including the effect of temperature feedbacks.

Hurricane Caterina "manmade"
Gore says that Hurricane Caterina, the only hurricane ever to strike the coast of Brazil, was caused by “global warming.” It was not. In 2004, Brazil’s summer sea surface temperatures were cooler than normal, not warmer. But air temperatures were the coldest in 25 years. The air was so much colder than the water that it caused a heat flux from the water to the air similar to that which fuels hurricanes in warm seas.

Japanese typhoons "a new record"
Gore says that 2004 set a new record for the number of typhoons striking Japan. It did not. The trend in the number of typhoons, and of tropical cyclones, has fallen throughout the past 50 years. The trend in rainfall from cyclones has also fallen, and there has been no trend in monsoon rainfall.

Hurricanes "getting stronger"
Gore says scientists had been giving warnings that hurricanes will get stronger because of “global warming.” They will not. Over the past 60 years there has been no change in the strength of hurricanes, even though hydrocarbon use went up six-fold in the same period. Research by Dr. Kerry Emanuel, cited by Ms. Kreider, has been discredited by more recent findings that wind-shear effects tend to nullify the amplification of hurricane strength which he had suggested, and, of course, by the observed failure of hurricanes to gain strength during the past 60 years of “global warming.”

Big storm insurances losses "increasing"

Gore says insurance losses arising from large storms and other extreme-weather events are increasing, by implication because of “global warming.” They are not. Insured losses, as a percentage of the population of coastal areas in the path of hurricanes, were lower even in 2005 than they had been in 1925. In 2006, a very quiet hurricane season, Lloyds of London posted their biggest-ever profit: £3.6 billion.

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