June 26, 2009

Slower winds mean pollution, crop damage

Declining wind speeds could damage crops, increase pollution and raise temperatures in cities, Iowa State University researchers say.

Wind speeds across the country have decreased an average of 0.5 percent to 1 percent each year since 1973, with the biggest declines in the East, the Northeast and the Great Lakes, the study said.

The study, to be published in the Journal of Geophysical Research -- Atmospheres, confirmed the researchers' previously reported findings that lower wind speeds could reduce potential wind-generated electricity.

But slower winds also could mean higher temperatures in fields and, thus, less-productive crops, which depend on wind for cooling, said Gene Takle, an Iowa State professor of geological and atmospheric sciences and agronomy.

Takle said slower winds also could cause more crops to be covered in dew, making them susceptible to fungus and plant disease.

In cities, slower winds can mean more heat and pollution, the study said.

. Less wind means less ventilation and less sweeping away of pollutants, Takle said in a news release.

Slower winds also would allow heat to linger and build during a heat wave, he said.

The decline in wind speeds and the possible impacts need further study, the researchers said.