Article
Global Warming:Has the Climate Sensitivity Holy Grail Been Found?
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August 19, 2008
[Editor’s note: Last summer University of Alabama Senior Research Scientist in climatology Dr. Roy Spencer and co-authors published a paper reporting their findings that (warming) cirrus clouds diminish rather than increasing in response to rising surface temperatures, thus making them a negative rather than a positive feedback, something they estimated could reduce by 75 percent the amount of warming to be expected from doubled CO2 in the atmosphere, since all the computer climate models assumed the opposite.
Spencer has continued his research along those lines, and in this simplified version for laymen of a paper he’s preparing for submission to the Bulletin of the American Meteorological Society he reports that his general results suggest climate sensitivity (which in the GW discussion means how much “global average temperature” will rise in response to doubled CO2) of 0.5C instead of the 3.0C projected by most models (because they assume large preponderance of positive over negative feedback).
This work should really shake up the alarmists. Its implications?
- The roughly 1.0C warming over the twentieth century, with far less than a doubling of CO2, cannot have come entirely from the increased CO2, and consequently natural causes must far outweigh human causes.
- Further, future warming from future increases in CO2 will be far less than the models have projected and the alarmists predict; consequently, its effects on sea level, severe weather events, vegetation, habitats, and biodiversity will be far smaller than the alarmists have claimed.
- That, in turn, both reduces the apparent need for reductions in CO2 emissions and worsens the benefit/cost ratio of such reductions.
Let me make that concrete. It has been common to estimate that compliance with the Kyoto Protocol would have achieved no more than about 0.2C reduction in global average temperature by the year 2100 against what would be predicted without it, at an annual cost to the global economy of about $100 to $200 billion, or $50 to $100 billion per hundredth of a degree per year ($4.5 to $9 trillion for the remainder of the century). Spencer’s work implies that climate sensitivity is only about one-sixth what the models underlying the estimate of Kyoto’s impact assumed. Consequently, temperature reduction to be achieved by compliance with Kyoto would be only about one-sixth the prior estimate, or 0.03C, or $300 to $600 billion per hundredth of a degree per year ($27 to $54 trillion for the remainder of the century).
Ponder that for a moment: $27 to $54 trillion to reduce “global average temperature” (whatever that means) by 0.03C by the end of the century! The case against CO2 emission reductions to fight global warming just got a whole lot stronger.–ECB]
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Read the article being discussed:
Roy Spencer W. Spencer, Ph.D.
WeatherQuestions.com, June 30, 2008
