Wind might be a favorite power source of the green energy movement, but winds across the United States appear to be slowing down and global warming may be the culprit.

These are the findings of a new study soon to be  published in the Journal of Geophysical Research.

The study has found that average and peak wind speeds, especially in the Midwest and the East, have been slowing since 1973. The states most affected are Ohio, Indiana, Michigan, Illinois, Kansas, Virginia, Louisiana, Georgia, northern Maine and western Montana with those bordering the Great Lakes experiencing the greatest wind speed changes.

According to study co-author Eugene Takle, professor of atmospheric science at Iowa State University, the trend is showing at least a 10 percent drop over the past decade.

Whether this is a trend is not yet clear. The study’s authors are quick to acknowledge that there are many variables that must be accounted for: changes in wind-measuring instruments over the years, a variety of climate computer models tracking changes, and obstacles such as tree growth and new buildings near wind gauges. All of these factors could affect the study’s results and skew the data.

As a result, the study raises more questions than it answers. But given the growth of wind power as a source of electricity, further research into changing wind speed is important.

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