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Yahoo
2 days ago
- Science
- Yahoo
What does climate change mean for agriculture? Less food, and more emissions
New research spotlights the challenge of growing food on a warming planet. Two recent studies — one historical and the other forward-looking — examine how rising temperatures have made and could continue to make agricultural production less efficient, fundamentally reshaping the global food system as producers try to adapt to hotter growing seasons. The findings illuminate the bind that farmers and consumers find themselves in. Agricultural production is a driver of climate change; it's estimated to be responsible for somewhere between a quarter and a third of global greenhouse gas emissions. But it is also hampered by the changes in weather patterns associated with climate change. While producers struggle to harvest the same amounts of food in the face of droughts, heat waves, and hurricanes, shoppers are more likely to face climbing food prices. The forward-looking study, published June 18 in Nature, analyzes the impact of warming temperatures on the caloric output of agricultural production. Researchers at the University of Illinois Urbana-Champaign and the Stanford Doerr School of Sustainability found that for every additional degree Celsius of warming above the 2000-2010 average, the global food system will produce roughly 120 fewer calories per person per day. In a scenario where the Earth experiences 3 degrees Celsius of warming by the end of the century, that's the equivalent of everyone on the planet missing out on breakfast, said Andrew Hultgren, lead author of the study. Hultgren and his colleagues compiled a massive dataset on the production of six staple crops in more than 12,000 regions spread out over 54 countries. They then modeled how different warming scenarios might impact crop production; they also factored in how farmers around the world are adapting to higher temperatures. What they found is that, even with adaptation, global warming is associated with an 'almost a linear decline in caloric output,' said Hultgren, who is also an assistant professor of agricultural and consumer economics at the University of Illinois Urbana-Champaign. Measuring agricultural adaptation and its impact on output was important, said Hultgren, because research often assumes that farmers either adapt perfectly to global warming or not at all. The reality is that adapting to any growing season challenges comes at some cost, and farmers are constantly weighing the business benefits of implementing new techniques. For example, one tool that corn farmers in the U.S. Midwest have to prevent hot days from thwarting their harvest is planting crop varietals that mature relatively quickly. 'Corn is very sensitive to extreme heat,' said Hultgren, 'so one very hot day can actually be bad for your entire growing season yield.' But fast-maturing varietals also often produce lower yields overall, meaning these farmers likely can't sell as much corn as they would have under cooler weather conditions, said Hultgren. 'So there's literally a cost of avoiding that extreme heat,' he said. A drop in the global supply of crops will also lead to an uptick in food prices. But Hultgren noted that the impacts of reduced agricultural output won't be evenly distributed. In wealthier countries such as the U.S., for example, those who can afford higher food prices will likely eat the cost. In poorer countries, these shifts could worsen food insecurity. Additionally, rising temperatures will impact producers unevenly; the study estimated that in a high-warming climate scenario, corn farmers in the U.S. will experience 40 to 50 percent losses in yield by the end of the century. Based on these projections, 'you wonder if the Corn Belt continues to be the Corn Belt,' said Hultgren. Meanwhile, other regional producers — like rice farmers in South and Southeast Asia — will see yields grow in the same time frame. 'There are absolutely regional winners and losers in this global aggregate,' he said. The historical study, published June 20 in Nature Geosciences, looks at one of the ways agricultural production contributes to global warming: land clearing. When farmers want to cultivate new cropland, they often start by removing the plants that are already growing there, whether that's grass, shrubs, or trees. When land clearing happens in carbon-rich regions in the Global South, like the Amazon rainforest, it increases deforestation and carbon emissions, said Jessica Till, the study's co-lead author. 'Deforestation in tropical areas is one of the most urgent issues and biggest areas of concern,' said Till, a research scientist at the University of Illinois Urbana-Champaign. (Till and Hultgren were not involved in each other's studies.) 'The more land you clear, the more forest you remove to create cropland, that's going to have a negative effect on the climate.' Till and the other study authors examined this feedback loop between agriculture and the environment: When crop production becomes less efficient due to extreme weather and heat, farmers must acquire and clear more land to boost production. That expansion in croplands then in turn results in higher greenhouse gas emissions, which exacerbates warming and makes crop production even less efficient. They found that, even with improvements in agricultural productivity (due to technological improvements like new seed varieties and precision fertilizer application), climate change was responsible for 88 million hectares, or 217 million acres, in cropland expansion globally — an area roughly twice the size of California — between 1992 and 2020. They also determined that this expansion was led by major agricultural producers, including the United States, India, China, Russia, and Brazil. Unsurprisingly, these countries were also the top five highest emitters of greenhouse gas emissions stemming from climate-driven expansions in cropland. Both Till and Hultgren noted that these shifts can also influence global trade. When certain regions see a decline in agricultural productivity, said Till, other regions will gain a competitive advantage in the international market for agricultural commodities. Erwan Monier, co-director of the Climate Adaptation Research Center at the University of California Davis, said he was not surprised by either studies' findings, and said they contribute to the growing body of research on climate impacts on agriculture. But he added that both come with caveats. Monier noted that the Nature study on caloric output fails to consider possible future advances in technologies like genetic editing that could make crops much more resilient to climate change. He said the paper demonstrates that 'in order to really limit the impact of climate on our ability to grow food, we're going to need a scale of innovation and adaptation that is really substantial, and that's going to be a real challenge.' Referring to the Nature Geosciences paper on the feedback loop between agriculture and climate, Monier said that it similarly does not take into account how farmer behavior might change in response to global warming. 'The fact is we have an ability to change what grows where,' said Monier. In the U.S., for example, where corn and soy production reign, farmers could choose to plant different crops if they see yields fall consistently. These growers will not 'continue growing corn with very low yields and invest more capital and land with very, very low returns,' said Monier. 'Farmers are going to move away to something that actually is more valuable and grows well' — and that, in turn, could reduce the need to clear more land. Monier acknowledged that the latter study might come across as quite pessimistic. But, he said, it underscores the importance of having difficult conversations now about how to grow enough food to feed the world's population as temperatures climb. In order to avoid serious losses in agricultural production, he said, climate researchers and institutions must work hand-in-hand with farmers, helping them understand the risks of global warming and seek out new ways of adapting. This work should be 'bottom up,' said Monier, rather than 'top down.' 'We need to engage the people who are going to be actually growing the food.' He added that this will involve work that extends beyond the academic sphere. 'I don't know if publishing in Nature and Nature Geoscience is the way to really drive the bottom-up adaptation at the scale that is necessary.' This story was originally published by Grist with the headline What does climate change mean for agriculture? Less food, and more emissions on Jun 30, 2025.
Kuwait Times
21-06-2025
- Science
- Kuwait Times
Climate change could cut crop yields up to a quarter
PARIS: Climate change is on track to reduce by 11 percent in 2100 the yields that today provide two-thirds of humanity's calories from crops, even taking into account adaptation to a warming world, scientists said Wednesday. As soon as 2050, this 'moderate' scenario in which greenhouse gas emissions peak around 2040 and slowly taper off - a trajectory aligned with current trends - would see global losses of nearly eight percent. And if carbon pollution worsens, the loss of calories across the same six staples - corn, wheat, rice, soybeans, sorghum and cassava - rises to nearly a quarter by century's end, the researchers reported in Nature. More generally, every additional degree Celsius of warming reduces the world's ability to produce food from these crops by 120 calories per person per day, or nearly five percent of current daily consumption, they calculated. 'If the climate warms by three degrees, that's basically like everyone on the planet giving up breakfast,' said co-author Solomon Hsiang, a professor at the Stanford Doerr School of Sustainability in California. The steepest losses will occur at the extremes of the agricultural economy: in modern, Big Ag breadbaskets that currently enjoy some of the world's best growing conditions, and in subsistence farming communities that typically rely of small cassava harvests. North America would be hit hardest, losing a fifth of yields by 2100 in the moderate carbon pollution scenario, and two-fifths if emissions from burning fossil fuels continue apace. Working with more than a dozen scientists, Hsiang and co-leader Andrew Hultgren, an assistant professor at the University of Urbana-Champaign, sifted through data from more than 12,000 regions in 55 countries. Previous calculations of how a warming world will impact crop yields generally failed to consider the ways in which farmers would adapt, such as switching crop varieties, shifting planting and harvesting dates, and altering fertilizer use. The scientists estimated such adjustments would offset about a third of climate related losses over the next 75 years in the scenario of rising emissions, but that residual impacts would still be devastating. 'Any level of warming, even when accounting for adaptation, results in global output losses for agriculture,' said Hultgren. With the planet about 1.5C hotter than preindustrial levels in the late 1900s, farmers in many regions are already experiencing longer dry spells, unseasonable heatwaves and erratic weather that undermines yields. The nutritional value of most crops also declines with hotter temperatures, earlier research has shown. The study revealed sharp variations in the impact of global warming on different crops and regions. In the 'worst-case' scenario of rising carbon emissions, corn yields would plummet 40 percent by 2100 across the grain belt of the United States, eastern China, central Asia, and the Middle East. For soybeans, yields in the US would decline by half, and increase by a fifth in Brazil. Wheat losses would drop by a fifth in eastern and western Europe, and by 30 to 40 percent in other wheat-growing regions: China, Russia and North America. Cassava would be hit hard everywhere it's grown. 'Although cassava does not make up a large portion of global agricultural revenues, it is an important subsistence crop in low- and middle-income countries,' the researchers pointed out. Among the six crops examined, rice is the only one that stands to benefit in a warmer climate, mainly due to warmer nights. — AFP
GMA Network
18-06-2025
- Science
- GMA Network
Climate change could cut crop yields up to a quarter, says scientists
PARIS, France - Climate change is on track to reduce by 11 percent in 2100 the yields that today provide two-thirds of humanity's calories from crops, even taking into account adaptation to a warming world, scientists said Wednesday. As soon as 2050, this "moderate" scenario in which greenhouse gas emissions peak around 2040 and slowly taper off -- a trajectory aligned with current trends -- would see global losses of nearly eight percent. And if carbon pollution worsens, the loss of calories across the same six staples -- corn, wheat, rice, soybeans, sorghum and cassava -- rises to nearly a quarter by century's end, the researchers reported in Nature. More generally, every additional degree Celsius of warming reduces the world's ability to produce food from these crops by 120 calories per person per day, or nearly five percent of current daily consumption, they calculated. "If the climate warms by three degrees, that's basically like everyone on the planet giving up breakfast," said co-author Solomon Hsiang, a professor at the Stanford Doerr School of Sustainability in California. The steepest losses will occur at the extremes of the agricultural economy: in modern, Big Ag breadbaskets that currently enjoy some of the world's best growing conditions, and in subsistence farming communities that typically rely of small cassava harvests. North America would be hit hardest, losing a fifth of yields by 2100 in the moderate carbon pollution scenario, and two-fifths if emissions from burning fossil fuels continue apace. Working with more than a dozen scientists, Hsiang and co-leader Andrew Hultgren, an assistant professor at the University of Urbana-Champaign, sifted through data from more than 12,000 regions in 55 countries. Erratic weather Previous calculations of how a warming world will impact crop yields generally failed to consider the ways in which farmers would adapt, such as switching crop varieties, shifting planting and harvesting dates, and altering fertiliser use. The scientists estimated such adjustments would offset about a third of climate related losses over the next 75 years in the scenario of rising emissions, but that residual impacts would still be devastating. "Any level of warming, even when accounting for adaptation, results in global output losses for agriculture," said Hultgren. With the planet about 1.5C hotter than preindustrial levels in the late 1900s, farmers in many regions are already experiencing longer dry spells, unseasonable heatwaves and erratic weather that undermines yields. The nutritional value of most crops also declines with hotter temperatures, earlier research has shown. The study revealed sharp variations in the impact of global warming on different crops and regions. In the "worst-case" scenario of rising carbon emissions, corn yields would plummet 40 percent by 2100 across the grain belt of the United States, eastern China, central Asia, and the Middle East. For soybeans, yields in the US would decline by half, and increase by a fifth in Brazil. Wheat losses would drop by a fifth in eastern and western Europe, and by 30 to 40 percent in other wheat-growing regions: China, Russia and North America. Cassava would be hit hard everywhere it's grown. "Although cassava does not make up a large portion of global agricultural revenues, it is an important subsistence crop in low- and middle-income countries," the researchers pointed out. Among the six crops examined, rice is the only one that stands to benefit in a warmer climate, mainly due to warmer nights. — Agence France-Presse
Fast Company
18-06-2025
- Science
- Fast Company
Climate crisis could wipe out half of U.S. crops by 2100, scientists warn
A major new study published in Nature examines how rising temperatures will impact global food systems, and the results offer a dire warning for wealthy countries. As the planet warms, the environments that grow the most-consumed crops around the globe are changing, but there's been a lot of disagreement about what those changes will look like. Counter to some more optimistic previous findings, the new study finds that every degree Celsius that the planet warms could result in 120 calories worth of food production lost per person, per day. The new analysis is the result of almost a decade of work by the Climate Impact Lab, a consortium of climate, agriculture and policy experts. The research brings together data from more than 12,000 regions in 55 countries, with a focus on wheat, corn, soybeans, rice, barley and cassava – the core crops that account for two-thirds of calories consumed globally. 'When global production falls, consumers are hurt because prices go up and it gets harder to access food and feed our families,' Stanford Doerr School of Sustainability Professor Solomon Hsiang, a senior author on the study, said in an announcement paired with the new paper. 'If the climate warms by 3 degrees, that's basically like everyone on the planet giving up breakfast.' Adaptation won't offset farming losses Some previous research has hinted that global food production could actually go up in a warming planet by lengthening growing seasons and widening the viable regions where some crops can grow. In Western American states like Washington and California, growing seasons are already substantially longer than they once were, adding an average of 2.2 days per decade since 1895. The new study criticizes previous research for failing to realistically estimate how farmers will adapt to a changing climate. While prior studies rely on an all-or-nothing model for agricultural climate adaptation where farmers either adapted flawlessly or didn't adapt at all, the new paper in Nature 'systematically measure[s] how much farmers adjust to changing conditions,' a first according to the research group. That analysis found that farmers who do adapt by switching to new crops or changing long-standing planting and harvesting practices could lessen a third of climate-caused losses in crop yields by 2100. But even in a best-case scenario of climate adaptation, food production is on track to take a major hit. 'Any level of warming, even when accounting for adaptation, results in global output losses from agriculture,' lead author and University of Illinois Urbana-Champaign Assistant Professor of agricultural and consumer economics Andrew Hultgren said. While wealthy countries are insulated from some of the deadliest ravages of the climate crisis, the new analysis reveals a U.S. food supply that is particularly vulnerable. Researchers found that the 'modern breadbaskets' that haven't yet explored climate adaptations will fare worse than parts of the world where extreme heat and changing weather has already forced farmers to adapt. 'Places in the Midwest that are really well suited for present day corn and soybean production just get hammered under a high warming future,' Hultgren said. 'You do start to wonder if the Corn Belt is going to be the Corn Belt in the future.' In a high-emissions model of the future where humans fail to meaningfully slow the march of global warming, corn production would dive by 40% in the U.S. grain belt, with soybeans suffering an even worse 50% decline. Wheat production would decline 30 to 40% in the same scenario. 'Because such a large fraction of agricultural production is concentrated in these wealthy-but-low-adaption regions, they dominate projections of global calorie production, generating much of the global food security risk we document,' the authors wrote, adding that farming in the U.S. is 'optimized for high average yields' in current climate conditions but is not robust enough to withstand a changing climate. 'This is basically like sending our agricultural profits overseas. We will be sending benefits to producers in Canada, Russia, China. Those are the winners, and we in the U.S. are the losers,' Hsiang said. 'The longer we wait to reduce emissions, the more money we lose.'
Int'l Business Times
18-06-2025
- Science
- Int'l Business Times
Climate Change Could Cut Crop Yields Up To A Quarter
Climate change is on track to reduce by 11 percent in 2100 the yields that today provide two-thirds of humanity's calories from crops, even taking into account adaptation to a warming world, scientists said Wednesday. As soon as 2050, this "moderate" scenario in which greenhouse gas emissions peak around 2040 and slowly taper off -- a trajectory aligned with current trends -- would see global losses of nearly eight percent. And if carbon pollution worsens, the loss of calories across the same six staples -- corn, wheat, rice, soybeans, sorghum and cassava -- rises to nearly a quarter by century's end, the researchers reported in Nature. More generally, every additional degree Celsius of warming reduces the world's ability to produce food from these crops by 120 calories per person per day, or nearly five percent of current daily consumption, they calculated. "If the climate warms by three degrees, that's basically like everyone on the planet giving up breakfast," said co-author Solomon Hsiang, a professor at the Stanford Doerr School of Sustainability in California. The steepest losses will occur at the extremes of the agricultural economy: in modern, Big Ag breadbaskets that currently enjoy some of the world's best growing conditions, and in subsistence farming communities that typically rely of small cassava harvests. North America would be hit hardest, losing a fifth of yields by 2100 in the moderate carbon pollution scenario, and two-fifths if emissions from burning fossil fuels continue apace. Working with more than a dozen scientists, Hsiang and co-leader Andrew Hultgren, an assistant professor at the University of Urbana-Champaign, sifted through data from more than 12,000 regions in 55 countries. Previous calculations of how a warming world will impact crop yields generally failed to consider the ways in which farmers would adapt, such as switching crop varieties, shifting planting and harvesting dates, and altering fertiliser use. The scientists estimated such adjustments would offset about a third of climate related losses over the next 75 years in the scenario of rising emissions, but that residual impacts would still be devastating. "Any level of warming, even when accounting for adaptation, results in global output losses for agriculture," said Hultgren. With the planet about 1.5C hotter than preindustrial levels in the late 1900s, farmers in many regions are already experiencing longer dry spells, unseasonable heatwaves and erratic weather that undermines yields. The nutritional value of most crops also declines with hotter temperatures, earlier research has shown. The study revealed sharp variations in the impact of global warming on different crops and regions. In the "worst-case" scenario of rising carbon emissions, corn yields would plummet 40 percent by 2100 across the grain belt of the United States, eastern China, central Asia, and the Middle East. For soybeans, yields in the US would decline by half, and increase by a fifth in Brazil. Wheat losses would drop by a fifth in eastern and western Europe, and by 30 to 40 percent in other wheat-growing regions: China, Russia and North America. Cassava would be hit hard everywhere it's grown. "Although cassava does not make up a large portion of global agricultural revenues, it is an important subsistence crop in low- and middle-income countries," the researchers pointed out. Among the six crops examined, rice is the only one that stands to benefit in a warmer climate, mainly due to warmer nights.
