Scientists have issued fresh warnings about China's environmental problems, saying more must be done to tackle issues such as global warming and desertification. They have urged the Government to spend more money to avoid ecological catastrophes, as coastal areas face a rapid rise in sea levels, while inland regions struggle with serious losses of arable land owing to drought and encroaching desert. Academics and officials found in recent studies that such problems had made China increasingly vulnerable to food shortages, climatic changes and other disasters. Speaking at public gatherings in Beijing, Vice-Minister of Forestry Zhu Guangyao admitted that the problem of growing deserts was 'still very grave', Xinhua (the New China News Agency) said yesterday. The campaigns, jointly organised by Beijing Forestry University, were aimed at rallying support and raising funds for desert-control projects. China's desert regions cover 3.32 million square kilometres - 34 per cent of its total area - and are mostly in the northern and western provinces. About 13 million hectares of farmland, and 100 million hectares of grassland, have been lost to deserts in recent years. Transport difficulties and water shortages are becoming more severe, as thousands of kilometres of railways and roads are threatened by shifting sands. Despite a national control project launched five years ago, only a relatively small portion of desert area, about 1.3 million hectares, has been recovered. And global warming has led to coastal regions becoming vulnerable to typhoons and floods, as higher sea levels have accelerated the submerging process. Du Bilan , a researcher at the State Oceanography Bureau, estimates that about 2.6 billion yuan (HK$2.41 billion) would have to be spent to repair the 'weak and fragile' embankments along China's 18,000 km coastline. Cities and villages in the Yellow River-Bohai Delta could face potential losses of up to 56 billion yuan if they failed to come up with the 560 million yuan needed to reinforce embankments and dykes, she said.