What is the climate change food system impact?
Climate change is disrupting our foodsystem, making it vulnerable to future crises.
In Kansas, more than 2,000 cattle died in an unprecedented heat wave. In Tunisia, fires razed grain fields. In southern China, historic floods damaged nearly 100,000 hectares of crops. In northern Italy, an agricultural lobby group warned that drought could take away half of the region's agricultural production.
All that was only in the month of June.
The global food supply is being affected by labor shortages caused by the pandemic, disruptions in the supply chain and the war in Ukraine. At the heart of all this is the climate crisis.
Climate change food system impact
"No doubt, he is always there. And from now on it's always going to be there," says Ed Carr, director of the Department of International Development, Community and Environment at Clark University.
Rising temperatures have been modifying climatic conditions and ecosystems around the planet for decades, before the pandemic or the war began. That is undermining the security of our food system and preparing it for new crises.
It's not all bad news, but the future of food hangs in the balance. This is what experts, scientific studies and international climate reports tell us.
What is climate change? What's the problem?
When humans burn coal and oil for fuel, they release carbon dioxide. The concentration of this gas in the atmosphere has increased by 50% since 1850, and the rate of increase has tripled since the 1960s.
All that carbon dioxide (in addition to other emissions, such as methane, from our agriculture, landfills and the destruction of the earth) is increasingly trapping the sun's heat, increasing global temperature.
The amount of carbon dioxide in the atmosphere (blue line) has increased along with human emissions (gray line) since the beginning of the industrial revolution in 1750. NOAA Climate.gov
Since 1850, human dependence on fossil fuels has caused the global average temperature to rise by 1.1 degrees Celsius, and scientists warn that we may face catastrophic warming of 1.5 degrees in 20 years.
Climate change food system impact details
It may not seem like much, but it is altering the planet's climate and ecosystems, to the detriment of the world's food supply.
Climate change is making droughts, floods, forest fires and heat waves more severe and frequent, according to the sixth assessment of the United Nations Intergovernmental Panel on Climate Change, published in installments over the past year.
Scientists cannot relate each of the phenomena to climate change, but research shows that rising temperatures affect the general occurrence of extreme weather events. These phenomena can devastate crops and kill livestock, as happened in Kansas, Tunisia, China and Italy last month.
Climate change is also causing chronic, long-term damage to our food systems.
As temperatures rise, scientists fear that some regions of the world will become inhospitable to the food on which economies depend.
Climate change food system impact studies
Several studies have shown that rising temperatures can reduce the yield of staple crops that account for two-thirds of all calories consumed by humans: wheat, rice, corn and soybeans. Last year, a NASA study predicted that the climate crisis would cause a 24% drop in the yield of corn, a crop that is part of countless food products and feeds livestock around the world.
"Most of the large grain-producing regions of the world are seeing some kind of climate signal, some kind of climate stress," said Carr, who is also a co-author of the IPCC report.
In 2021, researchers at Cornell University calculated that global agricultural productivity was already 21% lower than it would be without climate change. Other research suggests that rising carbon dioxide levels deplete the nutrients of some crops.
"We see less protein, less iron and less zinc in grains with higher CO₂ levels," says Toshihiro Hasegawa, who studies rice and collaborated on the food chapter of the IPCC report. "That's really concerning, and alarming for people who rely mostly on the diet of major staples."
Climate change food system impact examples
The oceans are also warming. That is forcing the migration of fish stocks, a critical source of protein for billions of people. Iceland, for example, is losing key fish, such as capelin and cod, which swim north in search of cooler waters. Rivers are also warming, which has led to a decline in salmon populations in the northwestern United States.
The oceans have also become 30% more acidic by absorbing some of the carbon dioxide that human activities have added to the atmosphere. Shellfish, such as oysters, clams and mussels, cannot escape the heating and acidification of the waters, so they are more likely to die.
The IPCC report states that the effects of climate change on certain fish stocks have not been sufficiently studied, but concludes that warming and acidification of the oceans are depleting fish stocks.
In general, the IPCC has already documented the decline in food quality or yield on all continents due to climate change, as shown in the following map.
