One day last month the skies over Beijing turned black and it lashed torrential rain for several hours. The sudden downpour, which frightened locals and tourists alike with its ferocity, was not an act of God, but the result of an army of 100 part-time rainmakers shooting rockets loaded with silver iodine into the clouds over the Chinese capital to create artificial rain.
It rarely rains in Beijing, which is on the edge of the Gobi Desert. Drought is adding to China's desertification problem, with 40 per cent of China's territory already desert.
Huge tracts of the country are being absorbed by sand as poverty-stricken farmers cut trees for fuel, graze their herds and divert rivers to their tiny plots.
The desert is expanding more quickly each year due to climate change and deforestation. The problem is taking its toll on northern China, the nation's breadbasket, where corn, soya bean and wheat production is concentrated.
According to figures published recently, desertification is costing China the equivalent of an annual $6.5 billion as the deserts expand at an alarming rate of 2,460 square kilometres a year, the area of an average Irish county.
The Gobi Desert is now only 70 kilometres from Tiananmen Square and the sand hills are said to be moving south at a rate of 10 metres a year.
Two decades ago, there was an average of 20 sandstorms whipping across northern China every year. This has increased to an average of 35 a year.
Most occur in spring, when the winds blow hardest from the north-west.
Millions of people in China have been suffering from two extremes of weather this year due to climate change - drought in the north and flooding in the south.
Rainstorms in southern China last month left dozens of people dead and 1.4 million people seriously affected.
Nearly half a million hectares of crops have been ruined by the floods and a number of major roadways have been destroyed.
On the other hand, the State Food Control and Drought Relief Headquarters (SFCDRH) has warned that China is on the verge of its worst drought in 10 years.
The drought has affected 22.7 million hectares of farmland, with a prediction of no harvest from almost 300,000 hectares of land. The drought also resulted in a shortage of drinking water for 15.8 million people and 11.4 million livestock.
Worst affected are Shenyang and Liaoning provinces in north China. There are reports that water for farm use has shrunk 80 per cent in the city of Tianjin, just two hours from Beijing, the fifth consecutive year the municipality has suffered severe drought, and grain production is expected to be down 10 per cent .
The State Environmental Protection Commission admits it is fighting a losing battle. Almost all the grassland covering 40 per cent of China's landmass has been degraded, only 57 per cent of river water meets basic standards and underground water supplies are being depleted by soaring demand from farmers and cities alike.
According to the Mr Juergen Voegele, head of the World Bank's Rural Development Sector Unit for China and Mongolia, China has the most active soil erosion problem in the world and potentially the most dangerous.
China needs to go back to basics, he told the Far Eastern Economic Review last week. Sustainable agricultural practices are needed to reduce herd sizes to allow land to lie fallow and regenerate.
The introduction of new types of vegetation, which can be used to fatten stall-fed animals, and ease the burden on the fragile, worn-out land of northern and western China is also needed, he said.
In some of the affected areas in China, there are between 100 to 150 people per square kilometre living on the land. "In the long term, only 15 to 30 people can be sustained on these areas," he said.
Last month the Asia Development Bank warned in a report that Asia was on the brink of environmental catastrophe. Rapid population growth, it said, had contributed to severe pressure on land, 30 per cent of which suffered some from of degradation.
China claims it is making an effort. It recently announced that a package of seven new laws and regulations are to be introduced to protect the environment while developing the economy.
The laws will cover the evaluations of environmental influences and are meant to limit sandstorms and desertification, result in cleaner production processes, control pollutant discharges, limit pollution from automobiles, and license the disposal of hazardous wastes.
However, experts say the new laws are unlikely to eradicate the roots of sandstorms in the short term. They say effective measures must be taken to curb expansion of the desert areas to avoid the creation of sandstorm sources.