Yukon Corn Harvests? Climate-Based Shift Will Also Threaten Bio-Diversity

Oct. 19, 2023

As new areas become suitable for planting, researchers predict that vast swaths of biodiversity will be at risk, particularly in northern regions and the tropics.

Climate change has the potential to restructure the world’s agricultural landscapes, making it possible to plant crops in places where they have never been viable historically. Within the next 40 years, these new growing regions could overlap with 7 percent of the world’s wilderness areas outside Antarctica, putting those ecosystems at risk, scientists reported Thursday. 

For their study, published in the journal Current Biology, the researchers ran computer models for how climate-driven shifts in precipitation and temperatures could alter the growing regions for 1,708 crops, with information on suitable conditions for each variety pulled from a database created by the United Nations Food and Agriculture Organization. 

The models were based on two different scenarios: one in which greenhouse gas emissions peak by 2040 and then decline, and one in which those heat-trapping emissions steadily increase beyond that time frame. While the first possibility would put around a third less wilderness at risk than the runaway emissions scenario, either situation would pose a significant threat to biodiversity if the land is cultivated, the study found. 

In the worst-case scenario, 72 percent of the land that is currently capable of being farmed will experience a net loss in total crop diversity, the researchers report. At the same time, the climate at higher latitudes in the Northern Hemisphere will become particularly suitable for agriculture. 

The problem is that these emerging agricultural frontiers lie within some of the last untouched ecosystems on Earth, particularly in Arctic regions, said Alexandra Gardner, the study’s lead author. 

“As soon as you go in and you start to do anything to that land, it loses its status as wilderness,” said Gardner, a postdoctoral environmental researcher at the University of Exeter in Britain. “Those areas are so precious for biodiversity, for actually meeting our climate goals in terms of reducing our carbon emissions. Those intact ecosystems are really good at storing and sequestering carbon.” 

Shuffling Agricultural Regions

Currently the world’s remaining wilderness is largely concentrated in high-latitude regions in the Northern and Southern hemispheres. However, these areas are proving to be disproportionately susceptible to warming as climate change advances. So while it may be difficult to imagine cornfields in isolated and frigid regions of the Yukon in Canada, it is within the realm of possibility, according to the study. Some of the largest expanses of emerging agricultural areas identified by researchers lie within the boreal forests of Alaska, Canada and northern Russia.

Tropical areas around the equator are projected to be suitable for the greatest number of crops, the scientists report. But Gardner said those regions were also likely to experience some of the widest losses and gains in suitability for growing some of the world’s most economically valuable crops, which could pose a major threat to biodiversity and local human populations.

Under the high-emissions scenario, for example, banana-growing areas in Central and South America, Africa and Southeast Asia would be redistributed, and 17.4 percent of the emerging agricultural frontiers for that crop would fall within tropical wilderness areas, according to the study. 

For wheat, which needs warmth and direct sun but cannot thrive in torrid conditions, 11.6 percent of the newly suitable growing areas are likely to fall within wilderness areas around the globe. The food with the highest potential for encroaching on wilderness is potatoes, with a potential 26.9 percent gain in suitable land. 

However, the study’s models are based only on temperature and precipitation shifts and leave out a key factor for agricultural growth: soil, said Monica Ortiz, a postdoctoral researcher at the Institute of Ecology and Biodiversity, Chile who was not involved in the study. 

“It’s a very useful study to kind of identify the opportunities and threats of agricultural expansion, and particularly thinking about wilderness areas,” said Ortiz. “Unfortunately, one of the biggest caveats of the particular model that they use is that it doesn’t consider soil.”

She added that many of the soil types in boreal regions in northern Canada and Siberia are currently unsuitable for agriculture. “They would need intensive management to make them productive lands,” she said.

And if agriculture does expand, Ortiz argues, soliciting the ideas of local stakeholders would be vital—particularly Indigenous peoples, who often stand to lose the most when wilderness is converted into large-scale farms. 

Preserving the Wilderness Option 

Even though some prospective growing regions will not necessarily be developed into farms, mapping out where they could overlap with wilderness areas is crucial for informing future management plans, Gardner said. 

“I just wish I had kind of all the answers about how to protect” them, she said, but “knowing that something’s under threat is the first thing—and then, you can take action to protect it.” 

If agriculture does expand deeper into wilderness regions, farmers will need to adopt sustainable techniques, like choosing crops that are suitable for the climate in a particular region and will not require excess use of fertilizer or water, the study’s authors write. 

Additionally, they point out, crop diversification could increase the productivity of existing farmland and buffer farmers from widespread losses in the event of extreme weather events like drought or heat waves. 

“If you’ve only got one crop, and that fails, then you’ve kind of lost everything,” Gardner noted.

Correction: A previous version of this story misidentified the country of residence for Monica Ortiz, who lives in Chile.

[Top photo: A small herd of Woodland Caribou on the tundra, Mackenzie Mountains, Yukon, Canada. Credit: by DeAgostini/Getty Images.]