Fields of corn in Siberia? Soy plantations in the Yukon? It’s not as far-fetched as it may seem.
Global heating will expand the frontiers of agriculture, a new study explains, making it possible in the near future to grow certain crops in places that were once inhospitable to them.
And that, the study’s authors say, could be a problem.
Climate change is moving the agricultural frontier northward into places that are currently mostly forested. The environmental consequences of developing these new frontiers, the researchers write, “could be catastrophic.”
“Boreal areas in Russia and Canada are going to be increasingly suitable for agriculture this century and, while that has big food production potential, it also has some serious environmental consequences,” said Lee Hannah, a senior scientist at Conservation International and the lead author of the study, published today in the journal PLOS One.
While expanding farming into new areas could help feed millions, it may well represent a Faustian bargain, coming at the expense of species richness and nature’s ability to regulate our rapidly heating climate.
What it all means
The study combined data on optimal growing conditions of a dozen major crops with predictive climate models over the rest of this century. It then examined how agricultural frontiers — the areas where crops could be grown where they couldn’t before — intersect with areas considered important for fresh water, wildlife and curbing climate change. Here’s the breakdown:
Fresh water: Frontiers will exist in places where farming currently isn’t practiced — including many mountainous places upstream from cities, Hannah explains. This could accelerate the loss of high-altitude “cloud forests” that provide water to cities such as Mexico City and Bogotá. Up north, agricultural frontiers in Canada and Russia have large downstream populations as well and, depending on the amount of fertilizer and pesticides used, “there’s a real possibility for downstream water quality concerns, impacts on the rivers and fish themselves, but also possibly drinking water for downstream,” Hannah said.
Biodiversity: One of the most striking findings of the study, Hannah says, is that agriculture will begin to move into tropical mountains known as global biodiversity hotspots — places with large numbers of rare wildlife species that are found nowhere else. “Our modeling suggests that up to 500 rare bird species might lose [their] habitat if these tropical mountain forests were cleared for farming,” Hannah said. By dispersing seeds and pollinating nearby plants, birds play a critical role in maintaining some of the most biologically important forests on the planet — as well as the farms in them.
Climate: Locked into the trees and soils of the new agricultural frontiers is climate-warming carbon. “It turns out there’s a lot of carbon locked up in the soils there because things don’t decompose very fast in cool conditions,” Hannah noted. Plowing land for farms releases soil carbon into the atmosphere, and the study found that a worst-case scenario of fully expanding agriculture into the new frontier would result in emissions equivalent to putting about 1 billion new cars on the planet — that is, nearly doubling the total number of cars on Earth.
“This is about 100 years’ worth of U.S. carbon emissions, roughly,” Hannah said.
Lessons from wine
Hannah and his team looked at 12 of the highest-value commodity crops in the world — including wheat, corn, peanuts, potatoes and oil palm — against two climate scenarios for the middle and end of this century. In every case, the territory for each crop shifted, some in unexpected ways. For example, climate models predicting more rainfall in Africa’s arid Sahel region could boost fortunes for locally important crops such as sorghum and millet.
The research was an outgrowth of a 2013 study led by Hannah that looked at the effects of climate change on wine production.
“When we did the study on wine, our models were showing wine suitability cropping up in all sorts of unusual places: Tasmania, north of Yellowstone National Park, places you really wouldn’t think of wine being grown,” Hannah said. “But in the years since that study’s been published, we’ve seen wine going into each one of these areas. Tasmania is a boomtown for vineyards right now; you’re seeing vineyards going into Montana. So just what the models showed is becoming reality.”
Looking forward
Many uncertainties remain about what these agricultural frontiers will mean for people and the planet.
For one, the existence of a frontier doesn’t necessarily mean it will be developed. “The impact of culture on agricultural frontiers is very important because some crops are only traded regionally,” Hannah said. “So, if locals don’t regularly consume that crop, it might not matter if the crop can be grown locally because people won’t grow it. For example, there are a lot of places in the world right now that are only suitable for growing potatoes, but because there isn’t local demand for potatoes, these areas are uncultivated.”
Many of the crops included in this study will simply expand the range where they can be grown; others, including wheat, will become easier to grow in some places and less so in others. “As we lose suitability in certain areas, that will create pressure to develop the frontier if we want to maintain wheat production,” Hannah explained.
If development of the frontier is unchecked, it could set forth a vicious circle in which adding more carbon emissions to the atmosphere unleashes even more warming, which unlocks further landscapes for cultivation.
Lastly, the mid-century and end-of-century predictions don’t necessarily reflect when the frontier will develop. “If farmers are going to grow crops in new regions, there needs to be some infrastructure to help them get their crops to market,” Hannah continued. “Some of the soils in Canada and Russia may still be frozen and may take some years to thaw out. And in many mountain environments, it might take years for soils to develop sufficiently to support agriculture.”
What to do?
There are several ways in which the impacts of frontiers can be abated, Hannah says.
One is by simply not developing the frontier. It’s perfectly possible, he said, for the suitability for a crop to increase with climate change but for a country or region not to exploit that suitability. Where a frontier suitability is exploited, farming practices matter. Where there’s a lot of organic matter in soils, conservation tillage — a method of farming that aims to reduce erosion as well as the amount of carbon released from soil — can have a significant impact.
“The intelligent play here is to figure out what areas could be really high-producing agricultural areas that don’t sit on high-carbon soils, possibly develop them to help feed the world, but then try and sequester these other soils,” Hannah said. “We need to leave them alone and reduce the amount of carbon that gets emitted from them, because we don’t want to have a runaway climate problem.”
Given that well over half of the planet’s agricultural frontiers are located in two countries, Canada and Russia will have key roles to play.
“The decisions of these two countries will be absolutely critical for the future of these frontiers. We want to have intelligent decisions made for food production, both for individual nations and globally, but Canada and Russia must remember that there are other, equally important issues at stake.”
Lee Hannah is senior scientist at Conservation International. Bruno Vander Velde is senior communications director at Conservation International. Molly Bergen contributed to this report.
Cover image: A team walks the perimeter of an agricultural plot, Tanzania (© Benjamin Drummond)
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