Using geographical knowledge to analyze the causes of weather changes

In recent years, extreme weather events will increase significantly. Drought will have a serious impact on agriculture (a temperature rise of 2℃ may lead to a 30% reduction in agricultural production). In southern Europe, rainfall will be significantly reduced. According to experts' estimation, by then, 60% of the world's residents will live in water-deficient areas. Under the background of global warming, extreme precipitation events in China have intensified in recent years, and the frequency of rainstorm and flood has increased; Drought events in northern China occur every year. After 1990s, many areas suffered from continuous drought for 5- 6 years. In summer, the weather of high temperature and heat wave increased obviously. The hottest year is 2006, which is also a year of frequent meteorological disasters in China. Tropical cyclones, droughts, sandstorms, acid rain and other disasters are numerous and serious.

According to the report of an international research group composed of scientists from many countries, global warming will cause the extinction of 1/4 of the world's land animals and plants in the next 50 years, that is, more than 1 10,000 species, which will have a disastrous impact on human beings. That is, 40% of biological species will disappear, while 20% of species in France will disappear. Polar bears and other animals in the Arctic will be the main victims like fish in coral reef waters. A study in Germany shows that climate warming will reduce oxygen in water, which will threaten the survival of fish. Some species will undergo major changes even if they are not necessarily extinct. For example, some southern plants will have to migrate to the north, while some migratory birds will no longer migrate.

Scientists in China found that since the Little Ice Age, the area of glaciers in mountain systems in northwest China has decreased by more than 7,000 square kilometers. In the past century, the water level in Qinghai Lake has dropped by 10 meters. Coastal areas will be hit by rising sea levels and more floods and storm surges, especially in the Pearl River Delta, Yangtze River Delta, Bohai Bay and other economic zones, when many small islands will no longer exist.

The survey shows that global warming has become the most important environmental problem in the eyes of Japanese people. In the United States, which emits the most greenhouse gases in the world, people are also rethinking their impact on the climate. More and more people call on governments that are unwilling to sign the Kyoto Protocol to take measures to reduce greenhouse gas emissions.

Experts pointed out that climate change is not only a scientific and environmental issue, but also an economic, political and national security issue. The impact of climate change will be long-term and huge, and more negative.