Iowans Can Elect To Combat Climate Change Now

A Time to Reap: Global Warming and Iowa, an analysis released today by Environmental Defense shows that climate change could increase temperatures in Iowa by 4.5 to 10 degrees in the next 100 years, with as much as 30 percent more precipitation than today. The changes mean heat waves, floods, and pest infestations could occur more often, last longer and inflict greater damage than today. However, Iowa farmers can adopt money-saving farm management practices now to reduce greenhouse gas emissions and avoid some of the potentially damaging impacts of climate change, the analysis notes.

Some models project that climate change, in combination with increasing greenhouse gas pollution and aggressive farmer adaptation, could mean higher crop yields and a longer growing season in Iowa, the analysis reports. But these scenarios fail to fully factor in the impacts on crops of extreme events like floods.

“The flood of 1993, which caused an estimated $1.15 billion worth of crop loss, may have been the worst natural disaster in Iowa’s history. A flood of such magnitude occurs about once every 100 to 200 years, but with current rates of climate change, Iowa could experience a so-called 100 year flood every 10 years by the end of the century,” said Dr. Janine Bloomfield, an Environmental Defense scientist and author of the analysis.

The number of days over 90 degrees is expected to increase with unchecked global warming, bringing the total of 90-plus degree days in Des Moines up from about 20 currently to between 35 and 70 by the end of the century, according to computer models used in this analysis. “In addition to greater risk of heat-related illness and mortality, high temperatures can significantly decrease corn yield, and very high temperatures can cause severe crop damage,” said Bloomfield.

Warmer temperatures and more frequent floods are expected to increase the range and abundance of weeds and insect pests, according to a study cited in the analysis. In addition, pests may arrive earlier in the season, causing damage to crops during important growing stages.

“Iowa farmers face an uncertain future if climate change continues unabated,” said Dr. Michael Oppenheimer, Environmental Defense chief scientist. “Fortunately there are steps farmers can take now to contribute to cutting the risks.” Farm management techniques that can reduce greenhouse gases include conservation tillage, installing permanently vegetated conservation buffers, and improved manure management.”

“Many greenhouse gas-reducing techniques, like conservation tillage, are also good farm management techniques and can save farmers money,” said Bloomfield.