Status of land degradation and acid rain in China

Status of land degradation and acid rain in China

Land degradation

China is one of the countries with the most serious desertification in the world. At present, China’s desertified land covers an area of 2.64 million square kilometers, accounting for 27% of the country’s land area. The land desertification area expanded by 1500km2 in the 1950s and 2100km2 in the 1970s. From 1994 to 1999, the average annual expansion was 3436km2, which is equivalent to the loss of two medium-sized counties in the coastal areas every year. According to preliminary estimates, more than 50 years after the founding of New China, China’s land

The desertified area has been expanded by more than 100,000 square kilometers, which is equivalent to a land area of Jiangsu Province that has been completely desertified. If no active measures are taken to reverse the increasing trend of land desertification, in the next 50 years, there will be double the area of land desertification.

The rapid development of the urban economy, the rapid expansion of the population, and the massive consumption of resources have caused serious damage to the original natural ecosystems in some urban areas. Most of the ground surface is covered by buildings and concrete pavements, which cause various environmental problems, affect the daily life of urban residents, and restrict the healthy development of the city.

Acid rain in China

China is a country with coal as its main energy source, and the largest coal producer and consumer in the world. Coal accounts for more than 70% of the primary energy structure. SO2 emitted during coal combustion is formed by the oxidation of the sulfur-containing components of coal during combustion. The sulfur content of coal varies with coal quality, and the average sulfur content of coal in China is 1.72%.

The chemical characteristics of acid rain in China are that the pH value is low and the ion concentration is high. Since the 1980s, acid rain pollution in China has been accelerating. In the 1980s, acid rain in China mainly occurred in high-sulfur coal-using areas such as Chongqing and Guiyang, and some areas south of the Yangtze River, with an area of about 1.7 million square kilometers. By the mid-1990s, the acid rain area had expanded to the east of the Qinghai-Tibet Plateau and the Sichuan Basin. The acid rain areas in central China, represented by Changsha and Ganzhou, are the most polluted by acid rain in the country, and the average annual precipitation pH value is lower than 4.0. The economic losses caused by acid rain are considerable. In 2004, acid rain occurred in 298 cities in China, accounting for more than 1/2 of the cities in the statistics. Acid rain cities are mainly distributed in Central China, Southwest China, East China and South China. Hunan and Jiangxi are the areas with the most serious acid rain pollution in central China.

Data show that since 1949, the proportion of thermal power in China’s total power generation has been above 75%, and it has remained above 80% in the 10 years from 1991 to 2002 (except 2001). SO2 emitted by thermal power plants has become one of the main sources of air pollution in China.

Currently, China’s total greenhouse gas emissions rank second in the world. Introduction by Dr. Su Yang from the Social Development Department of the Development Research Center of the State Council, in recent years, as China has entered a period of rapid growth of the heavy chemical industry, the thermal power industry has entered an explosive growth since 2002. The newly installed capacity of thermal power units in 2004 exceeded that of 2002 by nearly 100%. Obviously, this means that China’s greenhouse gas emissions will likely grow rapidly.

In addition, coal-fired power generation is the main culprit of ecological degradation in Shanxi and Inner Mongolia, and the main cause of sandstorms in Beijing.