Global Warming Warnings Called 'Gravely Flawed'

[wise1ray]

Six years ago, the BBC cited climate scientists in predicting that the Arctic would be ice-free in summer by 2013.

Instead, Arctic ice this August covered nearly a million more square miles of ocean than in August 2012 — an increase of 60 percent.

This has led Britain's Mail on Sunday to report: "Some eminent scientists now believe the world is heading for a period of cooling that will not end until the middle of the century — a process that would expose computer forecasts of imminent catastrophic warming as dangerously misleading."

The newspaper also asserted that global warming had paused since the beginning of 1997.

The pause is "important," the Mail stated, because predictions of ever-increasing global temperatures "have made many of the world's economies divert billions of pounds into 'green' measures to counter climate change. Those predictions now appear gravely flawed."Arctic ice now extends from Canada's northern islands to Russia's northern shore, blocking the Northwest Passage, and more than 20 yachts that had planned to sail it from the Atlantic to the Pacific have been left ice-bound.

Professor Anastasios Tsonis of the University of Wisconsin, who has investigated ocean cycles, said: "We are already in a cooling trend, which I think will continue for the next 15 years at least. There is no doubt the warming of the 1980s and 1990s has stopped."

The Mail article, which has been criticized and even dismissed by some global warming proponents, points to evidence that Arctic ice levels are cyclical. There was a massive melt in the 1920s and 1930s, followed by an intense re-freeze that did not end until 1979 — the year the U.N.'s Intergovernmental Panel on Climate Change says the shrinking of Arctic ice began.

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Yet these latest IPCC estimates of climate sensitivity may still be too high. They don't adequately reflect the latest rash of published papers estimating "equilibrium climate sensitivity" and "transient climate response" on the basis of observations, most of which are pointing to an even milder warming. This was already apparent last year with two papers—by scientists at the University of Illinois and Oslo University in Norway—finding a lower ECS than assumed by the models. Since then, three new papers conclude that ECS is well below the range assumed in the models. The most significant of these, published in Nature Geoscience by a team including 14 lead authors of the forthcoming IPCC scientific report, concluded that "the most likely value of equilibrium climate sensitivity based on the energy budget of the most recent decade is 2.0 degrees Celsius."
Two recent papers (one in the Journal of the American Meteorological Society, the other in the journal Earth System Dynamics) estimate that TCR is probably around 1.65 degrees Celsius. That's uncannily close to the estimate of 1.67 degrees reached in 1938 by Guy Callendar, a British engineer and pioneer student of the greenhouse effect. A Canadian mathematician and blogger named Steve McIntyre has pointed out that Callendar's model does a better job of forecasting the temperature of the world between 1938 and now than do modern models that "hindcast" the same data.
The significance of this is that Callendar assumed that carbon dioxide acts alone, whereas the modern models all assume that its effect is amplified by water vapor. There is not much doubt about the amount of warming that carbon dioxide can cause. There is much more doubt about whether net amplification by water vapor happens in practice or is offset by precipitation and a cooling effect of clouds.
Since the last IPCC report in 2007, much has changed. It is now more than 15 years since global average temperature rose significantly. Indeed, the IPCC chairman Rajendra Pachauri has conceded that the "pause" already may have lasted for 17 years, depending on which data set you look at. A recent study in Nature Climate Change by Francis Zwiers and colleagues of the University of Victoria, British Columbia, found that models have overestimated warming by 100% over the past 20 years.
http://online.wsj.com/article/SB10001424127887324549004579067532485712464.html