Climate Change Cooks Up Trouble for Mexican Agriculture
Climate change heats up Mexico's agriculture, slashing rain-fed crop yields by up to 80%. Corn, beans, wheat — all feeling the heat. New resistant crops and better research funding offer hope.
The effects of climate change are being suffered in Mexico and are especially severe for agriculture, especially rainfed agriculture, warned Francisco Estrada Porrúa, coordinator of UNAM's Climate Change Research Program (PINCC).
Despite the situation, there is scarce scientific literature on the subject, since there are only 96 articles on the subject, published from 1990 to 2022, in addition to the fact that the information is biased and does not study all crops of national importance, he acknowledged.
The researcher from the Institute of Atmospheric Sciences and Climate Change also participated in the Permanent Seminar on Agriculture, Food and Sustainability of the University Program for Sustainable Food of the UNAM, where he explained that projections indicate that these effects will be more pronounced throughout the century.
Available studies show, in general, a reduction in agricultural production towards the end of the century due to changes in both the average values of climatic variables and their extremes.
A possible expansion or intensification of agriculture is expected, with negative consequences on ecosystems and water and soil resources, as well as an increase in agrifood dependence and greater exposure to changes in international prices, said the economist at the online meeting.
"At the national level, reductions in soybean and rice yields could be greater than 50 percent, while for corn and sorghum they could exceed 40 percent, and 20 percent for wheat". Meanwhile, in sugarcane production, up to 11 percent, he argued.
In the case of corn, a decrease of up to 80 percent is projected in some areas of the country, and from 3.0 to 18.0 percent in terms of its climatic suitability, he said.
The university professor pointed out that recent studies projected drops in the yield of this rainfed grain of 10 percent at national level; regional, 80, 81.6, 84 percent; and state yields of up to 80 percent.
The states with the greatest aptitude for rainfed corn production at present — Jalisco, Mexico, Nayarit, Morelos, Michoacán, Guerrero and Colima — could lose 30 to 40 percent of their yields by the end of the century.
Currently, 23 states have production yields of this rainfed bean above one ton per hectare; by the end of this century only 11 will continue to produce at least one ton per hectare, he added.
The potential impacts observed on coffee are negative. Current records show reductions between 2010 and 2020 of 42.5 and 23.4 percent for irrigated and rainfed coffee, respectively.
By mid-century, wheat yields could fall by as much as 23.3 percent for rainfed and 20.0 percent for irrigated. This would be mitigated through the cultivation of new varieties that are more resistant to extreme weather conditions, he said.
Beans also suffer repercussions, with decreases of 10 to 40 percent due to higher temperatures and reductions in precipitation. However, there are varieties that have shown better adaptation to dry and warm climates, for example species of the Phaseolus genus such as P. filiformis, P. purpusii and P. maculatus.
He recalled that warming in Mexico is due to the increase in atmospheric concentrations of anthropogenic greenhouse gases, produced since the Industrial Revolution. It is faster than the global average: the rate of temperature increase is 2.88 degrees Celsius per century.
