Study Questions Link Between Monster Hurricanes and Global Warming

[NYer]

In recent years, a large number of severe Atlantic hurricanes have fueled a debate as to whether global warming is responsible. Because high sea-surface temperatures fuel tropical cyclones, this linkage seems logical. In fact, within the past year, several hurricane researchers have correlated basin-wide warming trends with increasing hurricane severity and have implicated a greenhouse-warming cause.

But unlike these prior studies, the U.Va. climatologists specifically examined water temperatures along the path of each storm, providing a more precise picture of the tropical environment involved in each hurricane's development. They found that increasing water temperatures can account for only about half of the increase in strong hurricanes over the past 25 years; therefore the remaining storminess increase must be related to other factors.

http://www.sciencedaily.com/releases/2006/05/060510095522.htm

[Bman]

Study: Human activities may breed hurricanes


www.chinaview.cn 2006-09-12 14:01:53



LOS ANGELES, Sept. 11 (Xinhua) -- Human-induced increases in greenhouse gas concentrations may raise ocean temperatures in hurricane affected areas of the Atlantic and Pacific oceans, U.S. scientists said on Monday.

A study conducted by atmospheric scientists from the Lawrence Livermore National Laboratory, National Center for Atmospheric Research, and other institutions has shown that the rising of sea surface temperatures of the tropical Atlantic and Pacific oceans over the last century is linked to human activities.

The study, based on 22 different computer models of the climate system, was published online in the Sept. 11 issue of the Proceedings of the National Academy of Sciences.

Hurricanes are complex phenomena that are influenced by a variety of physical factors, such as sea surface temperatures, wind shear, water vapor and atmospheric stability, according to the study.

While the increasing temperatures in the Atlantic and Pacific hurricane regions are not the sole determinant of hurricane intensity, they are likely to be one of the most significant factors, noted the researchers.

Earlier studies have uncovered evidence of the link between rising ocean temperatures and increases in hurricane intensity. This has raised concerns about the causes of the rising temperatures, particularly in parts of the Atlantic and the Pacific oceans where hurricanes and other tropical cyclones form.

Previous efforts to understand the causes of change in sea surface temperatures have focused on temperature changes, averaging over very large ocean areas, such as the entire Atlanticor Pacific basins, but the new work specifically targets changes of sea surface temperatures in much smaller hurricane formation regions.

http://news.xinhuanet.com/english/2006-09/12/content_5081118.htm

[NYer]

Does cleaner air make hurricanes worse? (http://www.msnbc.msn.com/id/13083495/)

From about 1950 to 1980, the cooling effects of aerosol particles in the atmosphere served to mask the warming effects of greenhouse gas emissions, the new thinking goes. Hurricane activity in the Atlantic was thus lower than it might otherwise have been during this period.

But since the 1980s, North America and Europe have reduced the amount of aerosols they pump into the atmosphere.

"Aerosols have had this masking, cooling impact for several decades, and now as we begin to clean up this atmosphere we may get something we didn't bargain for," Mann told LiveScience.

Heads you win - Tails you lose. Don't you just love science?