Connecting Climate Change and the Soil

Mar 01, 2024

By Debra Fitzgerald, August 30th, 2023

Renowned microbiologist and author coming to Door County

It may be safe to assume that the majority of the American population has limited encounters with soil, given that 97% of the country’s land mass is considered “rural,” but those rural areas are home to only 19.3% of the U.S. population, according to the U.S. Census Bureau.

The many ways in which soil is important may elude many of us as a result, whether as an important source of food and medicine, or as a filter to purify water, or as a barrier to prevent flooding. It’s also one of the planet’s biggest allies in the fight against climate change.

More than the atmosphere and all of the earth’s plants and trees combined, soil is an “enormous sink for carbon. The only source greater is the ocean,” said Jo Handelsman, speaking by phone from her office in Madison, where she is the director of the Wisconsin Institute for Discovery at the University of Wisconsin-Madison.

This is a sound reason for the Climate Change Coalition of Door County to feature soil during its 10th-anniversary celebration, The World We Make (see the sidebar), and to bring Handelsman to Door County as the event’s guest and speaker.

The grounding for her talk at the event will be her latest book, released in April by Yale University Press and titled A World without Soil: The Past, Present and Precarious Future of the Earth beneath Our Feet.

Handelsman was educated at Cornell University and the University of Wisconsin-Madison, where she earned her Ph.D. in molecular biology. Her career has included teaching at Yale University and the University of Wisconsin; groundbreaking studies in microbial communication and metagenomics; authoring more than 200 scientific research publications, 30 editorials and 29 essays; and co-authoring six books about teaching.

Prior to her current position, Handelsman was the associate director for science at the White House Office of Science and Technology Policy under President Barack Obama. It was during those three years as science adviser to the leader of the free world – “He was basically the smartest student I ever had,” she said about the former president – that she grew interested in what she called the “soil crisis.”

“When I left the White House,” Handelsman said, “I felt like the job wasn’t done in terms of enlightening the world, farmers, environmentalists on soil erosion, so that’s when I decided to write the book.”

The soil crisis includes the “billions of pounds of soil” that America has lost.

“A third of the land in Iowa has no topsoil left,” she said.

Iowa is second only to California as America’s largest agricultural producer, according to the U.S. Department of Agriculture. For Iowa to have lost so much topsoil – the rich upper layer where plants have most of their roots – “that’s pretty scary, and there are many others [states] on the way to having none,” Handelsman said.

The loss is scary because it takes hundreds of years for pulverized rock and organic plant material to metamorphose through a microbial process into “soil.”

“It’s a long, slow process,” she said. “We think we grow – this is a crude average – about a centimeter of soil every 100 years.”

In general, she said, we’ve lost soil since the 1850s due to farming practices, and three in particular: plowing, versus no-till planting; allowing the land to lie fallow and vulnerable after harvest instead of planting cover crops; and the complete lack of intercropping (corn, say, with strips of native prairie).

If the bad news is that traditional American farming practices make soil vulnerable to erosion, the good news is that erosion can be slowed and soil health improved relatively quickly. History shows this to be true.

“The Maya of central Mexico have been farming the same land for 4,000 years, and their soil has not given out,” Handelsman said. (By contrast, she said, some theories posit that the fall of the Roman Empire was caused, in part, by bad farming practices.)

But can farming operations that feed 332 million Americans adopt the same ancient practices that fed 2 million to 10 million Mayans? Handelsman said yes – even with monocultural operations in corn and soybeans. Brazil, for example, is the world’s largest producer of soybeans, and it has adopted no-till practices on two-thirds of its cropland, she said. By comparison, no-till planting is used on only one-third of American farmland.

U.S. farmers are increasingly using cover crops, and intercropping is just starting to gain awareness. An operation in Iowa achieved success with replacing 10% of a corn crop with strips of prairie to reduce erosion, Handelsman said.

But switching how food is grown in the U.S. is easier said than done.

“When I was in the White House, colleagues would ask why in the world would they [farmers] not do that,” she said. “Because a farmer who reduces production by 10% reduces crop insurance by 10% – and that’s just not tenable. Farmers work on such small margins; they can’t do that.”

Sustainable soils require sustainable farming policies that don’t require farmers to lose income, Handelsman said. That means changing the traditional subsidy programs in the U.S. Farm Bill – which is being renegotiated this year and funds programs ranging from crop insurance to healthful food access for low-income families. Those programs impact farming livelihoods and how and what kinds of foods are grown.

Having spent time in that tough political arena where numerous interest groups all jockey for position, Handelsman said it won’t be easy to get the government and the agriculture, insurance and banking industries to agree on different policies. There are signs, however, that understanding is growing about the need for sustainable soil-management practices.

“In President Biden’s very first speech, he actually mentioned cover crops,” Handelsman said. “I thought that was astounding for a president, getting into the weeds.”

Reserve Your Place For ‘the World We Make’

The Climate Change Coalition of Door County’s 10th-anniversary event will be held Sept. 20, 4:30-8:30 pm, at About Thyme Farm, 8425 Cty F in Baileys Harbor. The event includes dinner, music by Colin Welford, and a presentation by special guest and speaker Jo Handelsman, Ph.D., director of the Wisconsin Institute for Discovery, titled “The Earth Beneath Our Feet: Climate Change and the Soil-Loss Crisis.” Tickets are $40. Make reservations at climatechangedoorcounty.com.

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