Topeka ? A state legislator Wednesday criticized rejection of two coal-fired power plants in western Kansas, saying carbon dioxide emissions were good for crops.

“One of the really good things about CO2 is that plants perform better under stress (drought, etc.) with increased levels of CO2,” Rep. Larry Powell, R-Garden City, said in a letter disseminated to the media.

Powell said a recent study shows that over the next 50 years, “atmospheric CO2 enrichment will boost world agricultural output by about 50 percent.”

Last month, Kansas Department of Health and Environment Secretary Roderick Bremby denied permits for two 700-megawatt coal-burning plants near Holcomb, citing concern over climate change and the health effects of C02 emissions. Carbon dioxide emissions are considered a contributing factor to global warming.

Powell said he will work during the legislative session that starts in January to overturn Bremby’s decision.

But Jerry Glover, a soil scientist with the Salina-based Land Institute, said Powell is mistaken by thinking increased C02 in the atmosphere will help agriculture.

“At this point, no one knows all the details of the impact of global warming on agriculture, but it’s stacking up increasingly that it is not going to be entirely positive,” Glover said.

Glover said crops need more than C02 to survive. Global warming will increase temperatures in some regions, which means crops will need more water.

And climate change will disrupt distribution of water in unpredictable ways, which will decrease yields, he said.

Glover said he wasn’t familiar with the study that Powell cited, but said skeptics of global warming increasingly have evolved into global warming optimists.

Powell cited a report by Craig and Keith Idso of the Arizona-based Center for the Study of Carbon Dioxide and Global Climate Change. The center’s Web site has articles that criticize findings about the negatives of global warming.