Michael Mann is rethinking global-warming dogma. In an exclusive with the Allentown Morning Call on Sunday, he said that not all global-warming science is actually settled and it’s not certain that “the heat is reducing the world population of polar bears or that it increases the number of hurricanes.”
Among the propositions that remain unsettled, according to Mann:
1) That without a reduction in man-made CO2 emissions, large sections of coastal cities will be underwater by the end of this century.
2) That global warming is causing more frequent hurricanes.
3) That 1998 was the warmest year of the millennium between 1000 and 1999.
4) That current warmth of the planet is reducing the polar-bear population.
Not long ago, Mann had quite different views. This appeared in Nature just last August:
Michael Mann, a climate scientist at Pennsylvania State University in University Park and the study’s lead author, says that the results suggest that the annual number of hurricanes will continue to increase as a result of global warming.
Previous research has shown that warm sea surface temperatures could encourage hurricanes to form. The historical peak in hurricane activity coincided with periods of high sea surface temperatures, says Mann.
“This tells us that the relationship between sea surface temperatures and cyclone activity seems to be robust and gives support to the debate that we are likely to see an increase in tropical cyclone activity in response to global warming,” he says.
And what about the chapter “The Highway to Extinction?” in his 1998 book, Dire Predictions: Understanding Global Warming? In it, he writes of the “precarious future of the polar bear, which depends on expansive sea ice cover to reach and feed on seals. . . . Will these amazing creatures be an early casualty of human-caused climate change?”
Who knows when he will reconsider the “hockey stick” mantra — perhaps not long from now?
– Dana Joel Gattuso is a senior fellow at the National Center for Public Policy Research.