Indiana already feeling climate change effects

EVANSVILLE, Ind. — February's record-breaking rains and historic Ohio River flooding in Southwestern Indiana will happen more often as the effects of climate change continue to grow.

Indiana is already feeling the effects of climate change and those changes are occurring at increasing speed, a new Purdue University report says.

Those effects are likely to accelerate even more as heat-trapping gases from burning fossil fuels continue to buildup in the atmosphere, according to the Indiana Climate Change Impacts Assessment.

It is the first in a series of reports by the Purdue Climate Change Research Center. Future reports will examine specific impacts on health, energy, agriculture, infrastructure and ecosystems, said Jeffrey Dukes, the center's director.

The overview set out by the impacts assessment released last week is far from rosy. The number of hot days and their temperature will increase. As Indiana continues warming more rain will fall in heavier downpours. Winters and springs will be wetter, with less snow and far more rain, according to the report.

Southern Indiana, in particular, will be impacted the most by some of the effects such as rising temperatures and increasing rains. Average annual rainfall has already increased 5.6 inches statewide since 1895. However, that increase has been greater in southern and western portions of the state where yearly rain totals have increased more than 6.5 inches in some areas.

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More than 9 inches of rain but less than an inch of snow fell on the Evansville area in February, according to the National Weather Service. Warmer temperatures combined with heavy rains and melting snows upriver led to record Ohio River flooding. The rains also brought flashflooding throughout Southwestern Indiana, swelling rivers and creeks, swamping farm fields and washing out roads.

"That is consistent with the projections that we have for the state with climate changes, Dukes said. "There has been a really big increase in precipitation already in the state."

Indiana's average temperature is expected to increase 5 degrees or more by the middle of the century, according to the report. The number of extremely hot days will rise significantly, especially in Southern Indiana, which currently experiences about seven days of 95 degrees or above every year.

For Vanderburgh County, that means there could be 47 to 60 extremely hot days — over 95 degrees — per year by the middle decades of the century.

Dukes said the center's original 2008 assessment was done at the request of former Sen. Richard Lugar. However, after meeting with various stakeholder groups throughout the state in recent years, he said the center set out to more specifically address their questions.

Future climate predictions in the report are based on averages from 10 different global climate models using the two most likely scenarios for green-house gas emissions in Indiana. Those include a "medium" scenario in which some changes to curb current emissions occur and a "high" emissions rate scenario reflecting business as usual.

The report then looks at climate projections for the near future, middle and end of the century. A steering committee of 10 experts from a variety of fields contributed to the report.

"Certainly, I would say we have seen a lot of raised eyebrows," Dukes said. "For the average Hoosier it is like, 'this is maybe happening.' It is sort of a surprise for people to realize how it affects their daily lives."

Among the report's other key findings are that the growing season, represented by the number of frost-free days, has lengthened by 9 days since 1895 and is expected to increase by several weeks compared to the past average.

One result of this will be that the USDA plant hardiness zones for Indiana will shift to more Southern climates. Based on an average of extreme winter minimum temperatures, the zone map is used by gardeners and growers to help determine what plants will thrive in particular geographic areas. Under the most extreme scenario, Southern Indiana's hardiness zone will eventually mimic Northern Alabama's.

Extreme temperatures will bring an increased risk of extreme weather such as damaging winds, heavier rains and a longer severe storm season, according to the report, although there is still uncertainty about how frequent and intense those storms could be.

With the impacts of climate change already underway in Indiana, changes to curb greenhouse gas emissions are more likely to have an impact farther down the road, Dukes said. The momentum for climate change impacts Hoosier can expect in the near future is already in motion.

"It's an interesting sort of conundrum. We have a lot of warming already baked in to what is happening," he said. "The amount of change we can make now will be important for our children and grandchildren and their children."

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The ways climate change will impact daily life are many, said Melissa Widhalm, operations manager for the Purdue Climate Change Research Center.

For instance, warmer winters, higher temperatures and more rain could delay planting for farmers, while increasing pests and reducing crop yield. Hotter weather will increase cooling demand, potentially taxing utilities at a time when they are seeking to reduce emissions and burdening ratepayers with higher bills. Flooding and extreme weather bring increasing risk of property damage. Extreme heat increases the likelihood of heat-related illnesses and costly damage to infrastructure such as road pavement.

"It really does affect us right in our back yards," Widhalm said.

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