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ference reports, 110 countries of arable land fertile in reducing degree. In Africa, Asia and Latin America, by forest vegetation https://www.51lunwen.org/Ireland/
In the disappearance of forest vegetation, cultivated land development and pasture too overgrazing, soil erosion is serious. Bare land is weak, cannot resist erosion and long-term. In some places, the loss of soil in 100 tons per hectare. Excessive use of chemical fertilizers and pesticides, and air pollution of landing the toxic dust and the mud everywhere spraying, dangerous waste away everywhere, all of these are in the form of land is generally irreversible pollution. The soil is refers to the land surface has a fertility, can grow plants loose surface, its thickness in 2 m or so commonly. The soil for plant growth not only provide mechanical support ability, and can provide needed plant growth and development of the water and fertilizer, gas, heat and so on fertility factors. In recent years, due to the rapid growth of population, industrial rapid development, solid waste to keep the soil surface piled up and dump, harmful waste water to keep the soil seepage, the atmosphere and harmful gas parching also constantly with the rain landed in soil, led to the soil pollution. That interfere with the normal function of soil, reduce crop yield and quality, but also through the food, vegetables and fruit indirectly affect human body health substance, called the soil of pollutants.
Climate change and energy waste
According to 2500 representative experts predict, sea level will rise, many to densely populated areas (such as Bangladesh, China's coastal zone, and the Pacific and most of the Indian Ocean islands) will be flooded. A temperature rise will also on agriculture and ecological system brings the serious influence. It is expected that 1990-2010, Asia and the Pacific energy consumption will double, Latin America's energy consumption will be increased by 50%-70%. Therefore, the western between developing and developed countries should strengthen the energy saving technology transfer process. We shall adopt the special economic encourage methods, which makes the industrialists industrial resources use efficiency improvements of the technology. The greenhouse effect schemes
Biodiversity decrease
By urbanization, agricultural development, the forest, reduce and environmental pollution, natural areas have become more and more small, and that this has led to the extinction of the species. For some species went extinct will lead to many can be used to make new drug molecules to disappear, can lead many can help crops win over of severe weather to disappear genes, can cause even pestilence.
The forest area reduction
In recent decades, tropical countries to reduce the forest area is also very serious. In 1980-1990 years, the world has 150 million ha of forest disappeared. According to the current forest area of the decrease of the speed, 40 years later, some southeast Asian countries will never see a tree.
Fresh water resources is under threat
The beginning of the next century, the world will be a quarter of local chronic water shortage. Please remember, we can't make water, we can only try to protect water.
Chemical pollution
Industry millions of compounds with existing in air, soil, water, plant, animal and human. Even as the last of the natural ecological system of large ice cover is pollution. The organic compounds, those heavy metal, the poisonous products