Without immediate and broad-scale action to limit greenhouse gas emissions, global warming almost certainly will result in heat waves, changes in rainfall patterns and agricultural droughts, said a report by the UN climate change panel on Monday. Agricultural and ecological droughts were likely to become more frequent in western North America, said the report.
Occurrences of heavy precipitation would increase in central North America — the U.S. farm belt — and eastern North America. The scientists writing the report did not agree on whether central and eastern North America would see higher temperature extremes or more incidents of drought. Higher extremes in temperature are expected nearly everywhere on the globe.
Agriculture was mentioned as part of descriptions of how the world or its regions would be affected by climate change. For the most part, the report did not mention separate industries.
If the global temperatures increase by 2 degrees Celsius compared to pre-industrial levels, heat extremes would frequently strain the threshold for agricultural production and human health, said the report. The global goal is to limit the increase to 1.5 degrees Celsius. “Many changes in the climate become larger in direct relation to the frequency and intensity of hot extremes, marine heatwaves, and heavy precipitation, agricultural and ecological droughts in some regions, and proportion of intense tropical cyclones as well as reductions in Arctic sea ice, snow cover and permafrost.”
“From a physical science perspective, limiting human-induced global warming to a specific level requires limiting cumulative carbon dioxide emissions, reaching at least net zero carbon dioxide emissions, along with strong reductions in other greenhouse gas emissions,” said the report. “Strong, rapid and sustained reductions in methane emissions would also limit the warming effect resulting from declining aerosol pollution and would improve air quality.”
Agriculture is responsible for around 10 percent of U.S. greenhouse gas emissions, including methane, one of the most potent of the greenhouse gases. Livestock are a leading source of methane from agricultural production.
“Climate change becomes crystal clear for most people when viewed through the lens of water,” said Moira McDonald, director of Walton Family Foundation’s environment program. “Droughts, floods, mega-storms, wildfires, warming oceans and even having the ability to keep growing crops all make climate change painfully real in everyday life.”
Sustainable agriculture practice, which include reduced tillage, crop rotations and cover crops, “offer a path to feed a hungry planet, take care of farmers’ bottom line, help sequester carbon, while protecting soil and water,” said McDonald.
The Union of Concerned Scientists (UCS) said the climate change report was further evidence that “we’re in the midst of a crisis.” Nations are expected to boost their commitments to mitigating climate change at the UN climate conference in Glasgow from Oct. 31-Nov. 12. “Richer nations, whose emissions are the predominant cause of global warming impacts being experiences around the world, must take responsibility for rapid and deep emissions cuts and provide financial support so developing nations can make a low-carbon transition too,” said Rachel Cleetus of the UCS.
The climate report, “APC climate change 2021: The physical science basis,” is available here.
A news release on the report is available here.