September 12, 2006

Humans' GHG Warming Oceans, Intensifying Storms, Says NAS Paper

Human activities drive the warming of the oceans, which drive increasingly severe tropical storms, conclude 19 scientists in a The National Academy of Science report published this week. Some scientists still dispute whether recent severity of Atlantic tropical storms is a significant change or natural variation. Fewer dispute that global warming is happening and that human consumption of fossil fuels is a significant cause. Articles in the popular press are less frequently defering to the minority of sceptics and recognizing the scientific consensus, despite efforts by fossil fuel lobbyists to "teach the controversy."

The full article is in the September 12, 2006 online edition of the Proceedings of the National Academy of Sciences. B.D.Santer, et al, "Forced and unforced ocean temperature changes in Atlantic and Pacific tropical cyclogenesis regions" The full article costs $10 for immediate download, but here is the abstract (free):
"Previous research has identified links between changes in sea surface temperature (SST) and hurricane intensity. We use climate models to study the possible causes of SST changes in Atlantic and Pacific tropical cyclogenesis regions. The observed SST increases in these regions range from 0.32°C to 0.67°C over the 20th century. The 22 climate models examined here suggest that century-timescale SST changes of this magnitude cannot be explained solely by unforced variability of the climate system. We employ model simulations of natural internal variability to make probabilistic estimates of the contribution of external forcing to observed SST changes. For the period 1906-2005, we find an 84% chance that external forcing explains at least 67% of observed SST increases in the two tropical cyclogenesis regions. Model "20th-century" simulations, with external forcing by combined anthropogenic and natural factors, are generally capable of replicating observed SST increases. In experiments in which forcing factors are varied individually rather than jointly, human-caused changes in greenhouse gases are the main driver of the 20th-century SST increases in both tropical cyclogenesis regions."

See news stories about the article at: ABC News: Hurricane Warning (ABC News, September 11, 2006) and Report links global warming, storms (San Francisco Chronicle, September 12, 2006).

DougSimpson.com/blog

Posted by dougsimpson at September 12, 2006 07:46 AM