Climate change is on track to cause a lot of problems for the world's farmers, and the worst hit will be those who are the least able to recover.

Though rising global temperatures are expected to negatively affect agricultural production and food security in regions all over the world, poor farmers and those living in the tropics will be most affected. But if countries take steps to adapt to environmental changes, much of the food security risk could be offset, according to a new joint report by the U.S. Department of Agriculture, the National Center for Atmospheric Research and the University Corporation for Atmospheric Research.

"Never before has agriculture faced challenges of this magnitude. We've all seen the statistics: nine billion people by 2050. Feeding these new citizens will require at least a 60 percent increase in agricultural productivity. We must do all of this in the face of climate change that is threatening the productivity and profitability of our farms, ranches and forests," wrote Secretary of Agriculture Tom Vilsack in a statement

USDA released its latest report during Vilsack's visit to the Paris climate talks last week. He noted that the United States and the Department of Agriculture can lead by example by helping farmers and ranchers adapt to the effects of climate change.

"We don't face these challenges in a vacuum. These same conditions have dire effects across the world, especially for poor, rural smallholder farmers in developing nations. Drought in the western United States and drought in Central America threaten farmers and livelihoods, disrupt communities, and strain food systems. Increasing climate threats, whether it is drought, high temperatures, increases in pests, or wildfire, are separate symptoms of the same problem," Vilsack wrote.

The consensus-based assessment pulls together research from 19 federal, academic, nongovernmental and intergovernmental organizations, but stays away from offering policy recommendations. The researchers compared what would happen in either a low-emissions scenario where atmospheric carbon dioxide concentrations are around 421 parts per million by 2100, or a high-emissions scenario with atmospheric concentrations of carbon dioxide at 936 ppm by the end of the century. Under low emissions, temperatures would increase to 1 degree Celsius by 2050, then remain unchanged into the end of the century. With high emissions, temperatures would go up by 2 degrees by 2050 and 4 degrees by 2100.

Changes in production capacity were among the most direct climate change impacts on food security globally. The researchers found that crop yield increases seem to have declined globally by 2.5 percent per decade because of climate change. In tropical areas where plants are already growing in conditions that are close to the maximum of what they can tolerate, yield losses will be greater as temperatures rise. Warmer temperatures also facilitate the spread of plant pests and diseases. Livestock are at risk because hotter temperatures can make animals eat less and become less physically active, which translates into lower growth and reproduction rates, and less meat, milk and eggs.

Some bad omens for 2050 on
Environmental changes will vary in different parts of the world, with wet areas generally becoming wetter and dry areas becoming drier. Some high-latitude regions may even see short-term production gains as warming temperatures improve growing conditions. But these temporary benefits will evaporate by the middle of the 21st century under high-emissions scenarios, according to the report.

California's agricultural sector has already seen a preview of the impact that climate change could have on the West Coast. Vilsack noted that the state's persistent drought costs farmers $3 billion in 2015. Increases in invasive pests, diseases and severe weather have cost farmers billions in productivity, while a strong El Niño weather pattern has combined with a record wildfire year to create a damaging "perfect storm of disasters."

Changes like these around the world could have a significant impact on food security. In a worst-case scenario where high population growth combines with low economic growth, the number of people at risk of malnourishment would go up by 175 million in 2080 from today's roughly 800 million people without adequate food. If greenhouse gas emissions concentrations rise to 550 ppm, add 60 million more people to the list of those at risk of malnourishment.

But there's a silver lining — if overall greenhouse gas emissions drop below today's levels to 350 ppm, the number of people at risk doesn't change. And if the global population doesn't grow as fast and economic growth is strong, the number of food-insecure people could actually fall below 800 million, according to the report.

Ensuring food security isn't just about making sure that crops and livestock are able to survive in a changing climate. Food security also depends on the trucks that carry the food, the processing and storage facilities that help the food last longer, and the wholesalers and retailers that bring the food to consumers. Then there is all the underlying infrastructure that helps keep the entire food system running — fuel to power the trucks and roads for them to drive on, ports for international trade, and electricity to power cooling systems. Addressing food security will also require investments in infrastructure to prevent food loss and waste along the entire supply chain.

Helping farmers cope
Though agriculture in wealthier nations will be less hard hit by changing weather, farmers and consumers in the United States won't be immune to agricultural losses elsewhere in the world. Food imports could become more expensive, and farmers in the United States may begin to export more food to meet growing demand elsewhere, the report's authors wrote.

"Changes in society and changes in income will both be critically important to food security in the coming decades," said Brian O'Neill, a co-author of the report and a scientist at the National Center for Atmospheric Research, in a statement. "This means we have to do a better job of anticipating possible changes in income, governance, inequality, and other factors and a better job of understanding how they interact with food security and climate change."

Vilsack emphasized the importance of sharing information with farmers and scientists around the world. He named two of the organizations already working toward that goal— the Global Alliance for Climate-Smart Agriculture (GACSA), as well as the Global Open Data for Agriculture and Nutrition initiative (GODAN). Launched during the climate summit in New York in September, GACSA is a voluntary alliance of more than 100 national governments, research organizations and nonprofits. GODAN works specifically toward facilitating data sharing worldwide.

GODAN is calling for world leaders at the U.N. climate talks in Paris to make detailed historical weather data, high-resolution weather forecasts and climate change projections openly available. For farmers, having detailed information about what kind of weather to expect over the growing season is vital, and even more so now that climate change is already making weather patterns less predictable. GODAN is also asking for researchers to share other data relevant to agriculture, such as market prices for goods, land ownership, soil health, the amount and availability of water, agricultural inputs like fertilizer, pests, and diseases.

USDA is working to encourage farmers to voluntarily adopt more climate-friendly farming techniques. Farmers, ranchers and forest landowners looking for information about how changing weather patterns could affect their state can go to one of seven regional Climate Hubs. They can also participate in the 10 Building Blocks for Climate-Smart Agriculture and Forestry, a host of USDA initiatives to cut carbon emissions and increase sequestration of 120 million tons of carbon dioxide equivalent per year by 2025 — the equivalent of taking 25 million cars off the road.

"Collectively, these efforts make U.S. agriculture and forestry a more publicly visible part of the climate change solution in the United States and abroad. They demonstrate to the world that these sectors can provide solutions to reduce greenhouse gas emissions, while simultaneously boosting productivity to meet growing demands for food and fiber, stimulating the rural economy, and offering compatible environmental and economic benefits," Vilsack wrote.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500