A new tool finds abandoned farmland that could be used to fight climate change; 30 million acres have been identified

A map showing the percentage of abandoned farmland within a 36-square-kilometer area.
(University of Wisconsin graph)

U.S. farmland plays a crucial role in the country's battle against climate change, but how that role is structured and implemented is where opinions and landholdings clash. "Solar panels and energy crops are pitted against food production, while well-intended policy choices can create incentives for farmers to till up new lands, releasing even more heat-trapping gas into the atmosphere," reports Chris Hubbuch for University of Wisconsin News. "Abandoned farmlands could play a role in fighting climate change. A new study shows exactly where they are."

Scientists at the Great Lakes Bioenergy Research Center used "machine learning to map nearly 30 million acres of United States cropland abandoned since the 1980s, creating a tool that could guide decisions about how to balance production of energy and food," Hubbuch explains. "Their findings, published in the journal Environmental Research Letters, include the most detailed mapping of previously cultivated land in the U.S. to date."

Tyler Lark

Tyler Lark, one of the study's head researchers, told Hubbuch, "“If we can understand where these lands are and what the characteristics are, we can really understand their true potential for things like climate mitigation. . . . Whether it’s for solar photovoltaic, or agrivoltaics, or cellulosic bioenergy development, or just restoration of natural ecosystems: These sites could be great candidates for a lot of those applications.”

Until now, researchers used data from the Department of Agriculture to estimate how much land was no longer being farmed. "But there was no way of knowing exactly where that land was or when it was abandoned," Hubbach reports. "While satellite imagery has been around for decades, without recent advances in cloud computing, Lark says it was impossible to classify the nearly 2 billion acres of land in the coterminous U.S."

To find abandoned farms, researchers deployed their analysis tool to examine cultivation patterns. "The results accurately predict the location of abandoned croplands nine times out of 10 and can even pinpoint the year they were abandoned with about 65% accuracy," Hubbach writes. "The team found that more than 30 million acres of cropland were abandoned over those 32 years."