Climate change was one of a number of legislative priority issues discussed at the recent National LICA Legislative Committee meeting. Infrastructure and budget reconciliation bills include numerous provisions to reduce carbon emissions. A new report from the UN’s Intergovernmental Panel on Climate Change warns time is growing short to address global climate change, whose impacts are being seen in more extreme weather events such as drought and heavier precipitation, and changes to agricultural practices could take decades to have an impact on carbon emissions.
The report "is a code red for humanity," the United Nations panel said. "The alarm bells are deafening and the evidence is irrefutable: greenhouse gas emissions are choking our planet & placing billions of people in danger."
The report says that carbon dioxide levels in 2019 were the highest in the last 2 million years. Increases in carbon dioxide have a mixed impact on crops; high carbon dioxide levels can spur plant growth, but they also trap more heat, which can reduce yields.Humans are almost undeniably the cause, the report says. “Eight years ago we weren’t completely sure whether some of the extreme events we’re seeing were due to human-caused climate change,” said Jessica Tierney, an associate professor of geosciences at the University of Arizona and a co-author of the report. “Now we’re pretty sure that that is the case.”
Examples of the impacts may include “the extreme heat waves that we’re seeing around North America right now,” she said in comments on the report collected by the American Association for the Advancement of Science. “This new report says that those heat waves were unlikely to occur without human climate change.”
“The report provides new estimates of the chances of crossing the global warming level of 1.5°C in the next decades, and finds that unless there are immediate, rapid and large-scale reductions in greenhouse gas emissions, limiting warming to close to 1.5°C or even 2°C will be beyond reach,” the IPCC said in a news release.
“The report projects that in the coming decades climate changes will increase in all regions,” the IPCC said. “For 1.5°C of global warming, there will be increasing heat waves, longer warm seasons and shorter cold seasons. At 2°C of global warming, heat extremes would more often reach critical tolerance thresholds for agriculture and health.”
Changes in agricultural practices can begin to sequester some of the carbon released by agriculture over millennia, the report says, but such changes could take decades or longer to have an impact.
“Removing more CO2 from the atmosphere than is emitted into it would indeed begin to reverse some aspects of climate change, but some changes would still continue in their current direction for decades to millennia,” the report says.
It cites crop rotation, an increase in the amount of crop residues, use of cover crops, “optimization of grazing” and no-till or low tillage as among those beneficial practices. “With medium confidence, methods which seek soil carbon sequestration will diminish [nitrous oxide] emissions and nutrient leaching, and improve soil fertility and biological activity,” the report says.