LONDON (AlertNet) - Climate change could significantly depress yields of maize, wheat and rice, constrain supplies of animal protein, and force a rethink of diets and the crops farmers grow, researchers said on Wednesday.
Yields of the world's three biggest crops in terms of calories provided will decrease in many poorer countries as temperatures rise and rainfall becomes more unpredictable, according to a policy brief from the CGIAR Research Programme on Climate Change, Agriculture and Food Security (CCAFS).
By 2050, climate change could cause yield declines of 13 percent for irrigated wheat crops and 15 percent for irrigated rice in developing countries, the study warns. In Africa, farmers of maize - which is not well-suited to higher temperatures - could lose 10 to 20 percent of their yields, it adds.
Feeding livestock with maize and grain will also become more expensive, and fish availability will be increasingly limited, warns the analysis, which studied the potential effects of climate change on 22 of the world’s most important commodities, as well as water, forestry and agroforestry.
“The problems that climate change produces in the fields will be tackled in industrialised countries. It is the smallholder farmers in Africa and South Asia and the urban poor who spend too much of their wages on food - these are the people who will have less to eat in the near future unless we adapt at a much faster pace,” Robert Zougmoré, CCAFS programme leader for West Africa, said in a statement.
Hardier crops, including cassava, yam, barley, cowpea, millet and lentils, could fill the expected food gaps for poor communities, says the research.
Millet and lentils, for example, are highly nutritious and can withstand harsher growing conditions. Yet they are "not a bullet-proof adaptation option since certain climate stresses can reduce their yields as well", the brief notes.
"Ecosystem changes due to climate change may spawn shifts in the intensity of pests and diseases, including potato blight and beetles, that will further limit food production. Indeed, even if crops could withstand increased temperatures and decreased rainfall, their yields could drop because of these scourges,” said CCAFS scientist Philip Thornton, who authored the study.
Plant breeders are working to develop new crop varieties that are especially tolerant of heat, drought, flooding, salinity and crop diseases. But this effort is time-consuming, expensive and requires robust predictions of how growing conditions will change in different parts of the world in the next few decades, the research says.
Another problem lies in convincing people to switch from cultivating and eating a food staple such as maize to something new like cowpea - often described as "the poor man’s meat". "This cultural challenge is another facet of climate change adaptation that should get as much attention as plant breeding," the brief urges.
PLANET-WARMING FOOD SYSTEMS
A separate CCAFS report, also released on Wednesday, highlights the contribution food systems make to the greenhouse gas emissions that are warming the planet. It estimates that the processes needed to feed the world - from farming to storing, transporting and refrigerating food - accounted for 19-29 percent of global emissions in 2008, or the equivalent of 10,000-17,000 megatonnes of carbon dioxide released into the atmosphere annually.
“We are coming to terms with the fact that agriculture is a critical player in climate change. Not only are emissions from agriculture much larger than previously estimated, but with weather records being set every month as regional climates adjust and reset, there is an urgent need for research that helps smallholder farmers adapt to the new normal,” said Frank Rijsberman, the CEO of the CGIAR consortium.
Agricultural production, including the conversion of land for farming, is responsible for 80-86 percent of total food system emissions, although the level varies widely between regions, the CCAFS research says. It also examines the impacts of climate change before and after harvest, highlighting how every step of the food chain - from the seed to the cooking pot - is at risk.
Higher temperatures and flooding affect food storage and distribution, for example, and may cause more outbreaks of food-borne illnesses. The spread of diarrhoeal diseases - which already kill 1.9 million people a year - and livestock-related diseases will hit the poor in low-income countries hardest, the study warns.
"So far, the climate change discussion has focused on the need to reduce emissions and sustainably boost crop yields, but it is crucial also to include food safety in our foresight and planning," said lead author Sonja Vermeulen, the head of research at CCAFS.
The studies note that the pressure on food systems to cut down emissions and adapt to changing climates is increasing just as farmers must produce more food for a world population set to grow to 9-10 billion people by 2050.
“The good news is that, if farmers and food producers start to adapt now, they can stave off some of the dour food production and distribution scenarios laid out in this research. But they can’t face these complex, interrelated problems, which vary from crop to crop and region to region, alone. They need support from the highest levels,” Thornton said.
BACKING SMALL FARMERS
Farmers are often willing to experiment with new crops, but would benefit from information about local market prices and seasonal climate forecasts, as well as help with inputs - which could be provided by research organisations and development groups working in the field, Thornton told AlertNet from Nairobi.
More climate-related research should also be carried out for crops other than wheat, maize and rice, which have received most attention to date, he added.
Not all measures that could help small farmers are high-tech or costly, but many experts say a bigger share of agricultural research funding should be directed at this relatively neglected group.
Following a decade of slow growth in the 1990s, global public spending on agricultural research and development increased by 22 percent between 2000 and 2008 to $31.7 billion, according to a report issued last week by the International Food Policy Research Institute and the Global Forum on Agricultural Research (GFAR).
Much of the increase was in advanced developing countries like China and India, while research spending in low-income states grew on average by only 2 percent per year in that period and stagnated or declined in many.
"We are very concerned that unless spending increases dramatically, smallholder farmers in the poorer countries will continue to lack the essential knowledge, tools and technologies required to support their needs, and for production to be resilient in the face of the challenges ahead," GFAR Executive Secretary Mark Holderness said in a statement.