URBANA, Ill. — The latest Intergovernmental Panel on Climate Change (IPCC) report, issued February 27, contained dire warnings of consequences from unabated climate change, including negative impacts on agriculture and food production. Gerald Nelson, University of Illinois professor emeritus of agricultural and consumer economics, played a leading role in developing the report as the author of its chapter on “Food, Fiber and Other Ecosystem Products.” Nelson reported that increased heat waves, droughts and floods are already threatening the tolerance thresholds of plants and animals in many parts of the globe. 

“The IPPC is something that national governments set up a couple of decades ago to report on what the latest scientific literature says about climate change causes, impacts, adaptation and mitigation. Every six or so years, it releases an Assessment Report, called that because it ‘assesses,’ not reviews, the latest peer-reviewed literature,” Nelson said, in an email.

He explained that the report consists of three parts — WG1; the physical science of climate change, WG2; the various impacts from the changing climate and how nations might be able to adapt to them (this segment included Nelson’s contribution), and WG3; mitigation, or reducing emissions of greenhouse gas (GHG) emissions. 

“(The IPCC) are interested in new findings that are of relevance to national governments; much less so to regional or local. The new WG2 report is the first to have specific chapters devoted to regions, but they are very large. For example, the Midwest is a small part of the North American region,” said Nelson.

Negative impacts of climate change on food production are already visible, according to the report, and will become clearer as temperatures increase and weather patterns become more variable. Nelson notes that plants and animals are already evolving in specific locations, with climate change shifting them to different parts of the world and altering their territories.

The report concludes that weather extremes are beginning to occur in multiple locations simultaneously, inflicting impacts that are becoming more difficult to manage. It suggests that to avoid mounting loss of life, diversity and infrastructure, “ambitious and accelerated” action will be required to make significant reductions in GHG emissions. 

“So far, progress on adaptation is uneven and there are increasing gaps between action taken and what is needed to deal with the increasing risks,” according to the study, which details how climate change is interacting with global trends such as unsustainable use of natural resources, growing urbanization, social inequalities, losses and damages from extreme events and the coronavirus pandemic to exacerbate climate instability.

“Our assessment clearly shows that tackling all these different challenges involves everyone – governments, the private sector, civil society – working together to prioritize risk reduction, as well as equity and justice, in decision-making and investment,” said IPCC Working Group II Co-Chair Debra Roberts.

Unrelated to the IPCC report, Nelson told Farm World that spring and summer weather in the Midwest is dependent on the climate in the Gulf of Mexico. 

“Moisture flows north pretty regularly until the end of July or so and then shuts off. This works great for corn flowering, which is a critical part of the maturation process, and provides the moisture it needs for pollination and kernel development. Then the dry weather reduces moisture so the corn can be harvested. Climate change might change the timing, causing drying to start before pollination is done. That could result in a big hit to yields,” said Nelson, citing information he received from Eugene Takle, from the Department of Agronomy at Iowa State University. 

“The other critical period is planting. In recent times the amount of heavy, nighttime precipitation has increased quite a bit. Makes it harder to get into the fields. There’s a reason Iowans have enough equipment to plant the whole state in about a week. One adaptation has been seed coatings that keep the seed viable for much longer than the 2-3 days previously. But these are all adaptations to moderate climate change. We can expect a lot more.”

A lengthier growing season for the upper Midwest could be a direct result of climate change, Nelson noted. “The lengthening growing season is definitely a possibility. It might make possible more double cropping. Some farmers, at least in Illinois, already do some of this with wheat and sorghum. More of it might become feasible with a lengthening growing season,” he said. 

The IPPC report warns that any further increase of global warming will hamper efforts to combat climate change on the world stage. “The scientific evidence is unequivocal: climate change is a threat to human wellbeing and the health of the planet. Any further delay in concerted global action will miss a brief and rapidly closing window to secure a livable future,” said Hans-Otto Pörtner, IPCC Working Group II Co-Chair.

For a more detailed assessment on the causes and effects of Midwest climate change than what is offered within the IPCC report, the US National Climate Assessment (https://www.globalchange.gov/nca5), mandated by Congress, examines smaller, more specific regions of the United States. Its next report is due out in 2023.