p>LONDON (AlertNet) - Climate change is expected to reduce maize and bean harvests across Central America, leading to economic losses of more than $120 million a year by the 2020s and threatening the incomes of around 1 million small farmers, says a new scientific study
Researchers from the International Center for Tropical Agriculture (CIAT
) and the International Maize and Wheat Improvement Center (CIMMYT
) examined how the region's two most important food crops would be affected by higher temperatures and shifting rainfall patterns in El Salvador, Honduras, Guatemala and Nicaragua.
"Even with our most conservative estimates, it's clear that climate change could transform the agricultural landscape across Central America," Anton Eitzinger, a CIAT climate scientist and lead author of the report, said in a statement. "Conditions are already tough there; it's one of the poorest and most vulnerable parts of Latin America."
In some parts of El Salvador and Honduras that have poor soil, where much farming takes place, maize production could drop by around 30 percent by the 2020s, and on poor soils in Guatemala and Nicaragua, it could fall by around 11 percent, the study warns.
For beans, Honduras will be the worst affected by 2020, with a production decline of 15 percent, followed by El Salvador at 8 percent, Nicaragua at 6 percent, and Guatemala at 4 percent, the study says. In all four countries, bean production is expected to fall by up to 25 percent by 2050.
But in financial terms, the estimated annual losses for maize are five times higher than for beans, topping $100 million. The combined figure for both crops - close to $123 million - equals around 30 percent of their current values.
The report, part of a project led by the charity Catholic Relief Services, will be presented at a meeting of Central American donors, policy makers and development organisations in San Salvador on Thursday.
The study forecasts the effects of a 1 degree Celsius temperature rise by the 2020s, and a 2 degree Celsius rise by the 2050s, under a "business as usual" scenario for greenhouse gas emissions. Minimum and maximum daily temperatures will increase and water deficits will get worse due to less rainfall and higher evapotranspiration rates, causing heat stress to plants, it predicts.
The region's dry season could be extended and the "canicula", a short dry spell in July and August, could be more severe, clashing with a crucial stage of the maize production cycle, the organisations said.
Rains could be reduced during the bean planting season in September, with higher temperatures affecting flowering and seed production. The wet months of October and November are likely to see even more severe downpours, like those that destroyed crops and infrastructure in the region in 2011.
Widespread soil degradation will make the problems with changing weather worse, the study says. Farmers working on poor soils will experience greater losses than those with good-quality land, it predicts.INVEST IN SMALL FARMERS
Unusually, the researchers downscaled the climate models they used to small areas of between 1 sq km and 5 sq km, enabling much more detailed analysis of different terrains and local climate variations than other studies have provided.
Growing maize and beans will become pretty much impossible in some "hotspots", they concluded, whereas in other places, farmers could continue with those crops if they take action to adapt, such as using rainwater more efficiently and keeping soil in good condition. Some areas could even become newly attractive for cultivation, but many are in forests or on wetlands that may require protection from encroachment and degradation.
"What is needed now is political commitment and long-term investment in agricultural production in Central America," says the study. "Governments urgently need to invest in education and training to build institutional and human capacity, and to rebuild extension services that re-emphasise basic agronomy, soil and water management."
Agricultural investment should target smallholders who cultivate land irrigated by rainwater because they grow more than 80 percent of Central America's maize and beans, the study adds.
"Extension services across the region need to be reinvigorated to train small farmers in soil and water management," said Paul Hicks of Catholic Relief Services. "And governments need to lead - they have the ability to make a real difference through setting climate-smart agricultural policies."
With better agronomic practices and water management, maize and bean production - which is low now - could actually be boosted, even in the face of climate change, the report says.
Scientists should also focus on breeding new crop varieties that can better withstand heat and drought stress, "although we need to be wary of over-relying on this strategy", it adds.