Peru is considered to be one of the most vulnerable countries in the world to climate change. On the steep slopes of Chopcca, a community of 10,000 residents in the Andes, the rains come later, don't last as long and end more abruptly than they did only a few years ago. Frosts and hail hit earlier and more frequently. Fewer clouds drift by to moderate the extremes of temperature. Water shortages loom. In May, Mount Pastoruri, formerly a tourist attraction in the central state of Ancash, was removed from the list of snowcapped peaks because a third of its white cover has melted away. A 2002 study by the Tyndall Centre
for Climate Change Research in Britain found that the country's fragile mountain ecosystems, dependence on glaciers for water and extreme poverty make the job of adapting to the changes of global warming particularly difficult.
In the past few years, however, a funny thing happened on the way to catastrophe. Peruvian peasants have surprised the experts by coping with the warming. Small farmers in the Andean highlands have responded to changes in weather patterns by altering their planting season and varying their crops. Vulnerable mountain farmers are applying ancient strategies of risk diversification and a combination of homegrown experimentation and scientific know-how to adapt to the new weather patterns and their side effects.
It's difficult to overstate the challenge that these farmers face: a destructive synergy of climate change, overpopulation and land degradation runs the 8,000-kilometer stretch from Venezuela to Chile. As natural pasture is turned over to food crops, and population pressures decrease the amount of time fields lie fallow, virgin soils quickly grow depleted of nutrients and livestock go undernourished. "All the factors that create habitat degradation are made worse by climate change," says Stephan Halloy, director of the Andes biodiversity science unit for Conservation International.
The Andean farmers have felt the heat. Because of warming temperatures, crops now grow at higher altitudes than they did a few years ago. Farmers in Chopcca used to grow maize at 3,300 meters above sea level, but now plant at 3,600 meters. Pests have followed the crops to higher altitudes. In a remote corner of Cuzco province, native varieties of potatoes are being attacked by late blight, a fungus-like water mold. The Andean potato weevil, or potato white grub, eats potato leaves, and its larvae bore into the tubers underground. "We're in a war here with the Andean weevil," says Víctor Soto Ataypoma, mayor of Ccasapata, a village in Chopcca.
The campesinos have a natural weapon against climate change: the rich diversity of crop strains that flourish in the Andes's diverse system of habitats. Of the 34 known varieties of climate, Peru is home to 28 of them, and 70 percent of the country is covered by rain forest. Peru has 2,700 native varieties of potato and 35 types of corn, suitable to different climatic circumstances, including length of growing season, water and nutrient requirements, and pest resistance. Plant breeders and agronomists have stepped in to help Peru's farmers take advantage of this resource. In Chopcca, Yanapai, an agricultural NGO, has expanded the stock of native varieties of potato and tested organic methods for controlling pests. "Keeping alive a diversity of native varieties in a seed bank and complementing them with improved seeds should help the farmers adapt to climate change," says María Scurrah, a Cornell-trained plant breeder and coordinator of Yanapai.
This type of assistance has proved fruitful for other troubled farmers. In Cuzco province in 2003, when the temperature rose just enough to allow late blight to develop, farmers lost 90 percent of their harvest on 400 hectares. With some help from the International Potato Center in Lima, part of a worldwide network of research centers focused on staple crops, the farmers tested a score of potato varieties. They settled on two hybrids that were best adapted to local conditions and were resistant to blight. "Now that they produce enough for themselves and to sell at market, they are going to have a cash income," says Manuel Gastelo, a plant-breeding researcher at the International Potato Center.
A similar willingness to adapt has helped farmers cope with a shortened growing season for potatoes. In Huancavelica, the harvest this year was completed on June 2, nearly three weeks ahead of the usual harvest date of June 21, which didn't give the crop enough time to mature. "The potatoes are small," says Víctor Palomino Matamoros, 56, gazing at a communal field planted at 4,300 meters above sea level. Farmers in other parts of the country report that native potatoes now must be harvested as much as two months earlier than they traditionally have been. Fortunately, highland farmers learned from their ancestors to plant their crops in plots that are staggered at different altitudes. That flexibility, together with a modern penchant for experimentation, has allowed them to fine-tune their crops to prevailing weather patterns. In Chopcca, farmers experimented with 125 local varieties of potato. Farmer Juanita Quispe planted one variety last year on Dec. 8 "as a test," she says, and harvested nothing. Then her neighbor, Soto Ataypoma, found that wallash and ducis varieties mature more rapidly, "in three or four months," she says. By focusing on these two varieties, village farmers have increased their yields.
Adapting to shifting climate, of course, can be a hit-or-miss affair. On the one hand, potato farmers have taken advantage of the shorter growing season for potatoes by planting more cereal crops, such as corn, which require less rainwater. On the other hand, squeezing cereal crops into whatever growing season is available doesn't always work; crops can fail to fill out, leaving puny grains. Extreme cold, which stunts growth, can also foil the best-laid plans. During this year's growing season, temperatures were so cold that cow manure used as fertilizer never rotted to combine with and enrich the soil.
This being the international year of the potato, Peru's farmers have gotten a publicity boost. Agronomists, agribusiness and supermarket chains in Peru have promoted native varieties of potatoes. Frito-Lay has led the way with its Papas Andinas, made from traditional Andean varieties with marbled markings and sold as a premium product in high-end supermarkets. To sell to multinational food companies, Andean farmers would have to produce more consistently plump and sturdy potatoes. Adapting to global warming is the only path open to the Peruvian farmers. When the history of climate change in the early 21st century is written, they will deserve a special mention.