Extreme Conditions Endanger Global Food Supply, but There’s a Path Toward Resiliency
The global population’s increase from 1 billion in 1800 to over 7.7 billion today has meant many more mouths to feed, squeezing the amount of land available for agriculture and the ability to maintain soil quality. Meanwhile, the parallel increase in anthropogenic carbon emissions into the atmosphere has fueled climate change, putting even greater pressure on the agricultural sector’s ability to produce food.
As with anything related to the global climate system and biosphere, the picture is complex. For example, plants rely on carbon dioxide for photosynthesis, and so an increase in atmospheric CO2 can boost crop growth to a point. It’s the reason why some vegetable growers are using carbon capture to pump CO2 into greenhouses and improve yield.
However, a recent study published in Sustainability stated that although analysis showed that doubling the amount of CO2 could increase wheat and rice yields in northwest India by 28% and 15%, respectively, the warmer temperatures caused by the increased greenhouse gas concentration would negate the theoretical added crop growth.
According to another study in Nature Climate Change, the warmer temperatures due to human-caused climate change are estimated to have reduced global agricultural productivity by 21% since 1961, which is equivalent to losing the last seven years of growth.
In May, the monthly average CO2 reading taken at the Mauna Loa Baseline Observatory came in at 419.13 ppm CO2. It’s estimated as the highest level of CO2 in the atmosphere since homo sapiens have been around. With the readings increasing every year, the outlook for feeding the still-growing human population is troubling.
Climate change attacks crops on multiple fronts. Historically, agriculture has always been a risky venture due to unpredictable events wiping out or diminishing yields. However, climate change has supercharged the risk with more pronounced anomalies in precipitation causing extreme droughts in some areas and damaging floods in others. In addition, higher temperatures can stress and even kill plants and fuel the proliferation of pests that compound the losses.
“Agriculture is the most vulnerable sector to climate change, owing to its huge size and sensitivity to weather parameters, thereby causing huge economic impacts,” wrote the authors of Impact of Climate Change on Agriculture and Its Mitigation Strategies: A Review published in Sustainability.
Although crops in tropical areas are the most impacted due to higher average temperatures in those regions, the threats to agriculture from climate change are global.
The Sustainability study found that the global production of corn and wheat is projected to drop by 3.8% and 5.5%, respectively, due to climate change. Wheat losses will be pronounced in places like the Netherlands, which has been bombarded with extreme weather events. In Veracruz, Mexico diminished coffee yields by 34% could put producers out of business altogether.
Over the past several years, repeated flooding in the U.S. Midwest has left large stretches of agricultural lands completely submerged costing billions in damages annually. In Nebraska alone, 2019 floods costs ranchers at least $500 million and grain growers $400 million.
These events not only put pressure on the food supply but take a high toll on farmers. A study in the Proceedings of the National Academy of Sciences attributed three decades of warming temperatures to nearly 60,000 farmer suicides in India. Around the world, heatwaves are also leading to kidney disease and other conditions among farmers and others who work outdoors.
Drought is expected to play a significant role in future agricultural losses, with a jump in drought stricken areas from 15.4% to 44% projected by 2100, with the African continent especially affected. As a result, major crop yields could drop by over 50% by 2050 and 90% by 2100.
The study mentioned that the losses won’t be felt equally across the board. For example, the relatively dry regions of northern and eastern Sri Lanka stand to experience more significant losses than the cooler central highland region. Yet, the recent unprecedented heatwaves in the U.S. Pacific Northwest and British Columbia that claimed hundreds of lives and spawned a wildfire that nearly destroyed the village of Lytton illustrate that no place is secure from the heightened unpredictability triggered by climate change.
And it’s not just lower yields that are of concern. According to the study, the excess atmospheric CO2 makes food less nutritious, decreasing zinc and iron nutrients found in grains and legumes.
The more robust plant growth from CO2 also has a downside. The greenhouse gas fuels weed growth, thereby increasing agricultural labor requirements, need for herbicides and competition for water and nutrients.
The mounting pressures on agriculture are daunting, but some steps can be taken toward resiliency. For example, using biochar as a carbon sequestration method has the dual benefit of enriching soil quality. Water condensation technologies could be used to bolster irrigation in drought-prone areas. Additionally, agroforestry methods such as the Inga Tree Model have been shown to keep subsistence farmers rooted in one place while maintaining soil health.
With an estimated annual increase in global food production by 60% (above 2005-2007 levels) necessary to meet nutritional requirements for the world’s population in 2050, the urgency to implement resiliency measures is high.
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