Months of drought on the 18,000ft Tibetan plateau, followed by the worst blizzards in living memory and night temperatures of -45C, may kill up to a million yaks, cattle and sheep.
This is a disaster for 100,000 Tibetan nomads, who are entirely dependent on their herds and now face starvation. The Chinese authorities in Sichuan and Qinghai provinces have used up their relief supplies, and are turning to outside agencies for help.
Serge Depotter, a foreign relief worker who recently visited the worst- affected areas, said several dozen people had died from cold, and 28,000 more were suffering from frostbite and snow blindness. Respiratory infections, including tuberculosis, have become rife among the malnourished population.
Mr Depotter's organisation, the Belgian branch of Medecins Sans Frontieres, has organised a truck convoy to bring 1,200 tonnes of barley, medicines and other supplies to the starving nomads. "It is no longer possible to try to save the livestock, only the people," said an official of the Qinghai provincial government. But the herdsmen are entirely dependent on their animals for food, fuel, clothing and hides for their tents.
Sean Mayne Smith, a photographer who returned this week from the disaster area, said the Chinese authorities had had to dissuade the nomads from giving relief food to their animals. "Without their herds, these people have nothing," he said. "They are as poor as the people of Ethiopia."