The ‘Green Revolution’ transformed global agriculture. Now it’s adapting to climate change.

A scorching heat wave devastated Pritam Singh’s wheat crops in 2022.

During that year, temperatures soared to an astonishing 127 degrees Fahrenheit in Haryana, India, where Singh manages a 35-acre farm. The extreme temperatures severely shrank the wheat and accelerated its maturation, he recounted, resulting in only half his normal yield. Nationwide, the heat wave led to a significant drop in wheat production, amounting to 3 million metric tons. The states of Punjab and Haryana also reported disappointing grain yields, prompting the government to halt wheat exports to safeguard local food security.

Fast forward to 2024, despite witnessing the highest temperatures in over a decade, Singh approached the planting season with optimism. This change was largely attributed to the International Maize and Wheat Improvement Centre (CIMMYT), which provided Singh and millions of farmers across India with free buckets of climate-resilient seeds. The new seeds, which are currently being cultivated over 40 million hectares, had been specially bred to withstand extreme heat and minimal rainfall, thus giving Singh hope to avoid the losses he experienced in 2022.

“The per-acre production of wheat in 2024 exceeded our expectations,” he shared with Grist, crediting his success to the hardier seeds distributed just before the October sowing.

This initiative was part of CIMMYT’s long-standing commitment to developing high-yield crop varieties through traditional breeding methods since its founding in 1943. The organization focuses on selecting wheat varieties known for their resilience against pests and extreme climates. These varieties serve as “parent crops,” which are interbred over several cycles until the most robust specimens are identified among potentially hundreds of thousands of plants. This process differs from genetic modification, which alters an organism’s DNA; although CIMMYT does employ some genome editing techniques to enhance maize resilience.

CIMMYT was established by Norman Borlaug, a Nobel Prize-winning agronomist recognized for launching the Green Revolution, which significantly boosted global crop yields. The early trials—supported by the Mexican government and the U.S.-based Rockefeller Foundation—helped Mexico achieve self-sufficiency in wheat production by the 1950s.

Since then, CIMMYT has been supplying conventionally-bred grains to developing nations through nonprofit groups, agricultural universities, and other regional partners in 88 countries. It oversees one of the largest collections of genetic resources for maize and wheat globally. Through its breeding programs, CIMMYT has developed approximately two-thirds of the wheat varieties and one-third of the maize varieties cultivated worldwide.

As the organization adapts to one of the most pressing challenges of the twenty-first century—climate change—it has redirected efforts toward creating maize and wheat strains that can withstand erratic weather patterns and elevated temperatures. CIMMYT-India collaborates with institutions such as the Indian Institute of Wheat and Barley Research, the International Rice Research Institute, and the Indian Council of Agricultural Research, according to Ravi Singh, a former scientist of the organization. Their team also collaborates with provincial government institutions and private companies focused on wheat breeding.

These initiatives gain importance as heatwaves in various regions lengthen and intensify. In India, temperatures that typically spike at the end of May are beginning to rise weeks earlier. The northwestern states, such as Punjab and Haryana, historically experience five to six heatwave days yearly, but forecasts now anticipate nearly double that in the coming years.

Rising temperatures are poised to hinder wheat cultivation in these regions. They currently supply wheat, which satisfies the nutritional needs of approximately 35 percent of the world’s population. An alarming study projects that for each degree Celsius uptick in the average global temperature, agricultural farms could yield 120 fewer calories per person daily due to diminished outputs of staple crops. This potential decrease is particularly severe for wheat-producing areas in northern India. As the world’s second-most significant wheat producer, India’s threatened yields pose extensive economic and nutritional challenges.

A primary concern remains protecting the “grain-filling” phase, where wheat plants direct nutrients from their leaves to the husk for germination. Unfortunately, this crucial process halts when temperatures rise excessively, resulting in smaller grains compared to those grown in cooler conditions, according to investigations conducted by Scott Boden of the University of Adelaide, who specializes in wheat flowering times and grain quality.

Data indicating wheat growth in northern India underlines the crop’s sensitivity to climate change; temperatures exceeding 30 degrees Celsius (86 degrees Fahrenheit) threaten to obstruct the grain-filling phase. This has led hotter countries like India to increasingly seek crop varieties specifically bred to endure such volatility. In August 2023, the Indian government introduced 109 climate-resilient and nutritionally enhanced crop varieties, many of which were developed in collaboration with CIMMYT, according to Velu Govindan, a senior wheat breeding scientist at the organization.

These new breeds represent just the latest innovations. As of October 2024, roughly 2,600 varieties have been released over the past ten years by The Indian Council of Agricultural Research, an independent entity under the Ministry of Agriculture with which CIMMYT collaborates closely. More than 80 percent of these varieties successfully resist climate-related stressors.

For over sixty years, CIMMYT has been dedicated to identifying the specific genes that dictate crop responses to heat and drought conditions. At its Mexican facility, thousands of crossbred varieties are tested under climate simulations that mimic heatwaves and drought, according to Govindan.

“We search for the genes associated with stress responses,” he explained, “and utilize that information to strategically choose which parent plants to crossbreed.”

CIMMYT’s process begins with lab trials that span two to three years, followed by field testing to assess disease resistance, heat tolerance, and overall viability—sometimes requiring multiple years of further evaluation. Once validated, seeds are handed over to regional partners for distribution to farmers like Pritam Singh.

Nonetheless, CIMMYT acknowledges factors beyond its control may challenge the success of these new varieties. New pathogens might overcome existing resistance, or farmers’ reluctance to abandon familiar varieties presents additional hurdles, noted Ravi Singh.

The top 400 elite-performing varieties are sent to partner organizations in South Asia and Africa, where they are then provided free to farmers such as Pritam Singh. Singh employs a hybrid strategy; he has been testing various wheat types for nearly two decades, relying on expert guidance and his understanding of local conditions.

In the 1960s, under geneticist M.S. Swaminathan’s guidance, India embraced the Green Revolution to boost agricultural yields and combat malnutrition through high-yield crop strains. While it did result in increased grain production and reduced food costs, the Green Revolution has drawn criticism for promoting monoculture and the excessive use of pesticides, which negatively affected soil health, leaving many smallholder farmers unable to afford the new seed varieties or necessary chemicals.

CIMMYT seeks to fill this gap by aiming to assist small-scale farmers like Pritam, who typically lack access to more resilient seed options adapted for climate challenges.

Nevertheless, the region continues to face a multitude of complications that CIMMYT seeds cannot resolve alone. Dry soil is hampering crop production, as droughts reduce water retention in the topsoil and make it difficult for essential nutrients to reach the grains, according to Gurpreet Dabrikhana, a proponent of organic farming in Punjab. Dabrikhana expressed concerns that CIMMYT’s method doesn’t adequately adapt to local soil variations and might accelerate topsoil degradation, stating, “These approaches are very much crop-focused, not soil-focused.”

In South Africa, over 5,000 miles away, plant pathologist Norman Muzhinji from the University of Free State remarked on how institutions in his country have collaborated with CIMMYT to adopt and customize conventionally bred, high-yielding, and climate-resilient crop varieties to address food security and smallholder farmer needs.

This year, despite temperatures hitting 46 degrees Celsius, Pritam Singh’s crops thrived—a stark contrast to the disasters of 2022, when temperatures soared to 50 degrees Celsius. However, he notes luck played a role in his recent success as sporadic rain showers provided critical relief.

Singh remains cautious; in some past years, even the crossbred seeds he sowed failed to yield, resulting in substantial financial losses. This reality leaves him questioning, “The breeder varieties [from CIMMYT] may endure two to three degrees more heat than traditional strains, but what if temperatures rise even higher?”