Write disaster first, then write; At present, China's desertified land has reached more than 2.674 million square kilometers; The cultivated land and homes of nearly 400 million people in 47/kloc-0 counties in China 18 provinces and autonomous regions are threatened by desertification to varying degrees, and desertification is still increasing at a rate of more than 10000 square kilometers per year.

Among the seven major water systems, the water quality with no use value has exceeded 40%. More than 400 of the 668 cities in China are short of water. The urban population of China13 breathes seriously polluted air, and the land of13 is eroded by acid rain. In economically developed Zhejiang Province, the acid rain coverage rate has reached 100%. The frequency of acid rain is 1 1% in Shanghai and 12% in Jiangsu. In central China and some southern cities, such as Yibin, Huaihua, Shaoxing, Zunyi, Ningbo and Wenzhou, the frequency of acid rain exceeds 90%.

The maximum allowable emission of sulfur dioxide for basically eliminating acid rain pollution in China is120,000 ~140,000 tons. In 2003, the national sulfur dioxide emissions reached 265,438 0.587 million tons, an increase of 65,438 0.02% compared with 2002, of which industrial emissions increased by 65,438 0.04.7%. 10% to 30% of mammals, birds and amphibians are endangered.

Write how to protect (how to do) at the back. Finally, let's make a summary. About four paragraphs.