Unexpected Tropical Expansion Worries Climate Researchers

© Brian C. Howard

In yet more glum climate-related news, international researchers have found that the world’s tropical regions have widened over the past quarter century, most likely as a result of human-induced global warming. The study, published in last week’s issue of the journal Science, details how the tropics have expanded an average of 140 miles toward the poles around the globe.

Study co-author Thomas Reichler, a University of Utah atmospheric scientist, warns that if the trend continues unabated, rain-bearing storms would lash higher latitudes more frequently while depriving certain heavily populated regions, including southern Europe, of desperately needed winter rain and snow. The tropical widening could also expand the world’s subtropical deserts, eliminating biodiversity along the way. Meanwhile, increased warming of tropical ocean temperatures could further encourage the formation of Atlantic hurricanes.

The findings have caught climate researchers particularly off-guard because they are not consistent with the computer models they have rigged up to predict and help track the trajectory of human-induced global warming. Most models have predicted that the tropics would retain their size as the atmosphere warmed. While many of the other recent indications of a warming trend already underway have been consistent with predictions, researchers are left to wonder if the unexpected expansion of the tropics might be an indication that the climate is changing more abrubtly than expected.

Source: http://www.csmonitor.com/2006/0526/p02s02-sten.html