Climate Change Gets Local

LONDON, Ohio (DTN) -- At 6 feet, 8 inches tall, with a bushy, orange beard, Aaron Wilson towers very visibly above the crowds at Ohio State University's Farm Science Review.

But it's what he's talking about that really makes him stand out at the annual farm trade show.

In addition to OSU Extension, Wilson works at the Byrd Polar & Climate Research Center, studying the effects of climate change, an often controversial and misunderstood topic in agriculture.

What often gets lost amid the political debates and scientific conversations around climate change is how deeply personal it is for everyone, including farmers, Wilson said.

"Climate change has a personal impact on every person where they live, and those impacts vary depending on where you live," Wilson said. "I'm trying to bring down that global picture to a more local impact. What's changing in Ohio, and what are the potential impacts on ag?"

In Ohio and the rest of the Midwest, the answers to those questions are growing increasingly clear, Wilson said. Temperatures are rising and extreme rainfall events are more frequent.

THE IMPACT OF RISING TEMPERATURES

Many people tend to associate global warming with scorching-hot summer days, but the effects have been mostly concentrated in winters and summer nights, Wilson said.

"Our winters are warming about twice as fast as summers," he said. "Our coldest day of the year has warmed anywhere from 2 to 6 degrees compared to the mid-20th century."

Growers are also seeing more "false springs," where temperatures warm significantly in February, bringing many plants out of dormancy early -- only to be sabotaged by the usual spring freezes.

The pattern of warmer winters is likely to affect which crops farmers can grow and the pests that come with them, Wilson said. Insects will overwinter farther north, and more will begin to produce multiple generations within a season in the Midwest -- a phenomenon usually associated with the Southern U.S.

In the summer, overnight temperatures are on the rise, Wilson added. Specifically, nights where temperatures stay above 70 to 75 degrees are more frequent, which can have a serious effect on crop stress.

GETTING USED TO HEAVY RAINS

With warming temperatures comes a rise in atmospheric moisture, Wilson said. The amount of water vapor in the atmosphere has risen 10% to 15% in the past 50 years, which has increased the frequency of extreme rainfall events.

"These events where we're seeing 2- or 3-inch rainfalls -- we're seeing those occur more frequently, and we're also seeing a rise in the number of rainy days," Wilson said.

Specifically, the top 1% of heaviest rainfall events have increased 20% in the Midwest since the mid-20th century, he said.

That puts tremendous stress on cropland, from soil erosion to nutrient loss and plant health.

FARM SOLUTIONS

Overall, by 2030, climate researchers expect a state like Ohio to have the climate of southern Illinois. By 2100, the state will look more like Arkansas or west Texas, Wilson said.

"So what does farm management look like under those conditions?" he said.

That's where farmers and ag scientists come in.

"I'm a climate scientist, I need the farmer expertise," Wilson said. "What do we do together to bring around solutions?"

The growing movement to study and improve soil health is a good start, Wilson said. No-till and cover crop practices can help sequester carbon from the atmosphere -- the source of rising temperatures.

"Tillage releases a tremendous amount of carbon into the atmosphere," Wilson said.

New crop rotations, different hybrids and varieties, improved pest management practices and better soil health will all be crucial to growing crops in a warmer environment. But first, farmers have to pay attention and care, Wilson said.

People in agriculture often ask him why warming temperatures are a problem, given that the earth has seen temperature extremes in both directions over millions of years.

"There have certainly been periods where the earth's temperatures were a lot warmer," he said. "But did it sustain human life? That's really what it comes down to -- our relationship to the environment. How are we going to adapt to that future?"

The answer is likely a local one, Wilson concluded.

"The first thing is just knowing what your local impacts and threats are," he said. "If you start there, then you can prioritize your assets and how to build resilience in them -- in your farm, in your equipment. Have a plan of action."

See more from the Byrd Polar and Climate Research Center here: https://bpcrc.osu.edu/…

See more about Farm Science Review here: https://fsr.osu.edu/…

Emily Unglesbee can be reached at Emily.unglesbee@dtn.com

Follow her on Twitter @Emily_Unglesbee

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