Climate change in our own back yard

Not long ago it was possible to think of climate change as an issue for the future, something our children and grandchildren may have to confront. No more. The problem “has moved firmly into the present,” says the third National Climate Assessment, prepared by eminent scientists and released this week.

“Americans are noticing changes all around them,” the report says. “Summers are longer and hotter, and extended periods of unusual heat last longer than any living American has ever experienced. Winters are generally shorter and warmer. Rain comes in heavier downpours.”

Pryor_Sara

Sara Pryor

The report, which received extensive media coverage, included considerable work by Indiana University researchers. Sara Pryor, Provost Professor of Atmospheric Science, is a convening lead author of the chapter on climate change in the Midwest. Clinton Oster, professor emeritus in the School of Public and Environmental Affairs, is a lead author of the transportation section.

From submerged coastal areas to melting polar ice to increased Western wildfires, the most dramatic impacts tend to be distant from Indiana.  But the changing climate is already making itself felt in the Midwest, the report says. Pryor, who also edited a 2013 IU Press volume on climate change in the Midwest, listed six key messages for the region:

  • In the next few decades, longer growing seasons and higher carbon dioxide levels will increase yields for some crops, such as soybeans. But over time, those gains will be canceled by extreme weather, including hotter summers and wetter springs with more flooding.
  • The region’s forests will alter, with some species shifting to the north and heat-tolerant oaks and pines taking over. Forests now serve as carbon “sinks.” But increases in drought, fire and insect outbreaks will make them less effective at taking up greenhouse gases.
  • Public health will suffer from more frequent and intensive heat waves, higher humidity and degraded air and water quality. Pryor said the frequency of major heat waves has increased for 60 years in the Midwest, and hot, humid conditions are projected to keep increasing.
  • Clinton Oster

    Clinton Oster

    On the positive side, there’s a lot that can be done to reduce climate change in the Midwest, where per-capita emissions of greenhouse gases are more than 20 percent above the U.S. average. Shifting from coal to gas as a fuel can help; so can developing solar and wind.

  • Risks will increase to the Great Lakes, including changes in fish distribution, more invasive species and harmful algae blooms and beach pollution. The Great Lakes shipping season will get longer, although some years, like this past winter, will still see heavy ice cover.
  • Heavy rains and flooding have increased for the past century, and the trend is projected to continue, causing erosion and negative impacts on water quality and transportation. One problem: aging combined sewer systems that sometimes discharge untreated sewage.

“Cities are already working to remedy this problem – for example, with the federally mandated ‘Indy Tunnel’ in Indianapolis,” Pryor said. “These types of measures are very important to developing resilience to future climate change.”

IU’s Oster, who retired from active teaching in SPEA but continues to conduct research, analyzed the impact that various climate change scenarios on the U.S. aviation system. He said sea-level rise caused by climate change could put some low-lying coastal airports out of commission. But airports can be relocated and major flight patterns can be reconfigured. Airport issues will pale compared to other problems coastal communities face — including flooding of fixed-route railroads and highways.

 

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