The climate crisis will also change what kinds of crops farmers can grow. Some climates will become too hot for what farmers are growing now. Some climates will see more flooding, more snow, more moisture in the air, which will also limit what can be grown.
“The window is closing rapidly to have lower emissions and to keep warming to less than 2 degrees.That is the key message of this report,” said one of the report’s authors, Pamela McElwee, an associate professor of human ecology in the School of Environmental and Biological Sciences at Rutgers University.
The report found that quantitatively food nutrition could also decline. Wheat grown at high carbon dioxide levels, for example, will offer 6-13% less protein, 4-7% less zinc and 5-8% less iron, according to experiments done with these plants.
“We are studying how this would translate into the food we eat and also in a range of different crops, we are seeing similar results,” said one of the report’s authors, Cynthia Rosenzweig, a senior research scientist at the NASA Goddard Institute for Space Studies, where she heads the Climate Impacts Group.
Given that extreme events like the summer’s heat wave in Europe are increasing in magnitude and intensity, food systems are already showing some strain, she said.
Undernourishment has long been a concern of scientists who watch the climate crisis closely.
When you don’t have enough to eat it reduces your ability to function physically. It can diminish your ability to think clearly. It puts you at a greater risk for chronic disease and death, studies show.
While still too many people don’t have enough to eat, the world had been making progress in this area. In the 1990s, 1.01 billion people were thought not to have enough to eat. By 2015 it was 80.5 million, or about 11% of the global population, according to the US Department of Agriculture.
The climate crisis could reverse this progress.
A study published in May that looked at the production of the top 10 global crops — barley, cassava, maize, oil palm, rapeseed, rice, sorghum, soybean, sugarcane and wheat — found that because of the climate crisis, the world has already seen a reduction of 35 trillion calories every year. That equates to about 1% of food calories lost each year.
“That means you are removing food calories for about 50 million people, that’s already happening,” said study author Deepak Ray, a senior scientist with the Institute on the Environment’s Global Landscapes Initiative with the University of Minnesota. “Maybe in the future we will see even more lost, unless we prepare for it and draw down the carbon emissions.”
Ray said the climate crisis effects regions differently. Europe, Southern Africa, South Asia and Australia are feeling the most negative impact of food production due to the climate crisis so far. In the United States, Illinois has seen an 8% reduction of corn yield, but in states like Iowa and in the upper Midwest, there have been some gains in production due to climate change, Ray said.
High-income countries will likely be able to cope, but areas like Sub-Saharan Africa and parts of Asia and India will become even more vulnerable. The rural poor are the least able to adapt, studies find.
“It’s a very tough problem and for many countries that are already not food secure, hunger could become a much much larger issue,” Ray said.
Plant physiologist Lewis Ziska does agree. His work has contributed to the IPCC report. His past work with the US Department of Agriculture found that the rising CO2 levels have had a negative impact on the nutritional value of certain crops such as rice, and the climate crisis has reduced crop yield. It has also negatively impacted floral development, meaning that the pollinators, bees and butterflies, that rely on that pollen are put in jeopardy by the climate crisis.
“Bees play an essential part of agriculture, many aspects of the food chain,” Ziska said.
He considers food one of the most important issues policy makers should look at in the wake of the climate crisis.
“Food is the greater leveler among people,” Ziska said.
Imagine if you have a bunch of people in a room that don’t like each other, he said — if there is plenty of food in the room, they may look at each other suspiciously, but they will likely get along. If, however, you make them all stay in the room for an extended period of time and start to remove the food so there is not enough to go around, that’s when relationships get strained.
“All the hatred and fear and anxiety comes out of having not enough to eat, that’s why it is so important to adapt now and so important to look at critical issues like food security,” Ziska said.
But he remains concerned about how the United States’ political will to adapt. President Donald Trump has consistently confused much of the science around climate change, and proclaimed he would pull the United States out of the Paris Agreement.
Ziska had been working at the USDA on climate change for years alongside “very good people who are in the department still,” but quit his job in protest.
“Research and adaptation plans are essential for survival,” said Ziska, who is now with Columbia University, where he will continue his work.
Scientists, he said, need to keep pushing to advance ways the planet can adapt and continue reducing the climate crisis negative impact on food. He thinks “It is essentially where the corn silk meets the soil.”