Trouble at the top

Farmers living in the mountaintops of Peru, more than 4,000m above sea level, face devastation from climate change - but one charity is helping them to adapt, writes Rory Carroll

A huge slate-grey cloud laden with hail looms slowly over the ridge, seemingly close enough to touch, and to the farmers on this Andean peak it is like a Zeppelin on a bombing raid. If the cloud empties its belly here, the freezing pellets will devastate their potato crop.

One farmer races to the corners of the field to light piles of dried manure, sending up plumes of dark smoke. Another loads gunpowder into what resembles a stovepipe and blasts fireworks skywards. The heat and smoke, they hope, will soften hail into rain and save the crop. So begins another battle in the struggle for survival on the roof of Latin America.

This scene happens almost daily on the mountaintops of Peru, more than 4,000m above sea level, and it is not new. For centuries nature has inflicted extreme weather conditions on the herders and farmers who inhabit the eerie and starkly beautiful landscape. There are no trees, few shrubs and the air is so thin visitors must gulp to breathe. These farmers are one of only two groups in the world to live so high (the other is in the Himalayas). Surviving here is a fight against the elements using ancient tactics, such as blowing smoke at menacing clouds.

What is new, however, is the abruptness, frequency and ferocity of the hail. "It comes with virtually no warning. And not just at certain times of the year, like when I was a boy, but year round," says 48-year-old Sergio Mamani, wrapped in a brown poncho and sporting the multi-coloured pointy hat typical of his people. "You have a flourishing crop and then suddenly the hail destroys the leaves. You lose everything."

It is not just the hail that has changed. There is less rain so the earth is drier and browner. Days are warmer and nights colder, to the extent that herds of alpacas, indigenous domesticated animals which resemble big sheep with long necks, are freezing to death. The alpacas are also getting sicker because the occasional warmer temperatures bring disease-carrying insects which were once confined to the valleys. "It's not the way it was," says Mamani.

Scientists agree. A growing stack of statistics and academic studies say that Andean farmers are in the front line of climate change. Rising temperatures have melted a fifth of Peru's glaciers in the past 20 years, a retreat visible in photographs used in Al Gore's documentary, An Inconvenient Truth. El Nino-related events have grown more extreme, flooding some areas with rain, causing drought and conflicts over water in others. Toads and foxes have dwindled while rats and mosquitoes have thrived. Peru contributes just 0.4% of global carbon emissions but reaps disproportionate consequences because of geography - its deserts, mountains and tropical forests are especially sensitive to change - and its poverty. Communities such as those in the highlands are near-destitute and on the borderline of survival. "We have fewer options than a developed country, we're more vulnerable," said Valentin Bartra Abensur, a climate change expert in the capital, Lima.

For Sergio Mamani and his family, part of a 150-strong Quechua commmunity at Chuntapata Yanaccocha, a wilderness lost in the clouds above the city of Cusco, it means an age-old fight is increasingly tilted against them. Smoke and fireworks do not always avert hail. And even if the potatoes survive, the alpacas may not.

These quizzical, fluffy white creatures provide not only milk, cheese and meat but also fibre for clothing, insulation and bedding. Virtually the only livestock that can live on such thin scrub, alpacas are vital to Peru's 1.5 million Quechua and Aymara highland dwellers. Periods of intense cold known as friaje, driven by south pole winds, have become more frequent and icier, turning pasture into wastelands. In 2003, temperatures plunged to minus 35C and more than half the herds died.

An even graver threat is disease. Instead of rain-fed streams, alpacas now drink from pockets of muddy, melted hail which can cause an infection that attacks the nervous system. Others succumb to parasitic flatworm. It was unknown in the highlands until warmer temperatures attracted snails which host the parasites. "We spend almost all our income on medicine for the animals," says Isabel Roa, tiny, agile and looking older than her 39 years.

The battle is far from lost. Adaptation is a word which does not exist in the Quechua language but that is exactly what the farmers are doing with the help of charity group Practical Action. Families have built mud and stone shelters with tin roofs, called cobertizos, into which up to 50 alpacas are herded when temperatures drop. Along with basic veterinary kits, lowland male alpacas with greater resistance to disease are being introduced in the hope their offspring will inherit that resilience. High-energy blocks of barley enriched with syrup are milled and stored as a contingency for frozen pastures. Different types of indigenous potato more able to withstand frost are also being hauled up the mountains.

Practical Action instructs the farmers at a whitewashed building with a green tin roof a short ride down the valley from Chuntapata Yanaccocha. In batches of up to 18, evenly split between men and women, the classes learn how to get more out of fertiliser and how to produce hardier crops and herds.

"We don't have much but we're receiving training and we can share that with our neighbours," says Bernardino Maxi, 43, soon to be a newly graduated "kamayoq", or farmer trainer. Asked if they expected their children to be farming in 30 years, despite climate change, the students nod.

Adaptation may be toughest in the north of Peru where the supposedly "eternal ice" of the Cordillera Blanca of tropical glaciers is melting. At 5,200m above sea level the glacier known as Nevada Pastouri appears majestic, with a frozen azure lake at its base. Yet the slope of discoloured black rocks betray the fact that just 20 years ago the glacier stretched an additional 500m down the valley. An average annual temperature rise of 0.2C is pushing it back 20m annually. At that rate there will be nothing left within several decades. Skiiers have already abandoned the area.

Seasonal melting used to supply Peru's hydroelectricity, agriculture and industry but as the glaciers vanish and the population grows a water shortage worsens. Instead of swelling rivers and lakes, much of the run-off water evaporates. "We have 20 to 25 years to avert a crisis," says Cesar Rodriguez, Practical Action's regional head. With agriculture using 80% of Peru's water, and non-existent or inefficient irrigation losing about half of that, one obvious solution is better farming techniques. In hamlets like Primorpampa, where small plots of maize and avocado destined for export are etched into steep slopes, that means installing underground pipes to regulate flows. Practical Action has started a pilot scheme in which it pays for the materials and families do the digging.

Pablo Mendez, 49, agreed to install 10,000 metres of pipes beneath his two-hectare plot on the promise of doubling his yield using just half the water. "Let's see what happens," he says cautiously. Farmers like him on the upper slopes have enough water and little incentive to invest in conservation largely for the sake of farmers down in the valley as well as distant cities and industries. By showing that such farmers can still agree to change, the hope is that local and national government will follow up with regulations and compensation payments to promote conservation on a wider scale.

"It's not easy to persuade people to adopt new techniques," says Rodriguez, clambering up the slope from Mendez's tiny farm. "The challenge is not technical, it's social and political. We're trying to change centuries of custom in just a few years".