Enlarging farmland due to global warming can further spur climate change

Enlarging farmland due to global warming can further spur climate change
Photo: US Department of Agriculture

Russian authorities have repeatedly stated that the country can take advantage of rising temperatures to expand agriculture into areas where farming is not possible at the moment. However, recent research shows that such an approach can accelerate global warming even more because of a high carbon level in fertile soil.

Climate change can expand farmland globally by almost a third but will also bring significant environmental threats, including a risk of increased emissions from soils, warns Thomson Reuters Foundation. In a new study published in PLOS One scientific journal, international researchers examined which new areas may become suitable for growing 12 key crops including rice, sugar, wheat, oil palm, cassava and soy. More than half of the land identified in the study lies in Canada and Russia, while the rest includes the mountains of Central Asia and North America’s Rocky Mountains.

In Canada alone, global warming can at least double the country’s farmland to 2 million square kilometres, consider the study’s authors. “This is the positive aspect,” says Krishna Bahadur KC, an adjunct professor at Canada’s University of Guelph. According to the United Nations, food production needs to increase by about 50% by 2050, when the global population is expected to reach nearly 10 billion.

Drought in Russia, July 2010. Photo: Sergey Metik

However, environmental experts believe that enlarging farmland can further accelerate climate change, as some of these new agricultural frontiers have particularly carbon-rich soils. “As soon as you start [farming] you will see emissions. So global warming will shoot up,” explains Ronald Vargas, secretary of the Global Soils Partnership and a land management officer at the Food and Agriculture Organization of the United Nations. According to Vargas, Russia and Canada hold about a third of the world’s organic carbon stock found in the top layer of fertile soil, and half of that carbon can be released into the atmosphere within a decade if the land is cultivated.

Thus, if agriculture extends into all areas identified in the study, there will be little chance of meeting the Paris Agreement goal of limiting global temperature rise to 1,5 degrees Celsius above pre-industrial levels. Extending farming to frontier areas also poses risks to global biodiversity as well as indigenous people, says the study adding that the world needs government policies to “optimise food production, biodiversity and ecosystem services under climate change” instead of simply favouring agricultural expansion. “We should proceed but we should move very, very cautiously and [be] mindful of the potential environmental impacts,” says Krishna Bahadur KC. He proposes an environmentally aware approach that may include protecting areas with carbon-rich soils or levying high carbon taxes on conversion of such land for farming.

By Anna Litvina