What is climate?
Climate is the general state of the atmosphere in a certain region of the earth for many years, and it is the comprehensive expression of various weather processes in this period. Various statistics (mean, extreme, probability, etc. Meteorological elements (temperature, precipitation, wind, etc.). ) is the basic basis for expressing climate. Climate is closely related to human society, and many countries have recorded climate phenomena for a long time. During the Spring and Autumn Period in China, the sun shadow was measured by a standard table to determine the season, and there were 24 solar terms and 72 climaxes in the Qin and Han Dynasties. The word climate comes from ancient Greek, which means inclination, meaning that the climate in different places is related to the inclination of the sun's rays.
Due to the different distribution of solar radiation on the earth's surface and the different physical processes of different underlying surfaces such as ocean, land, mountains and forests under the action of solar radiation reaching the surface, the climate has obvious regional characteristics besides the temperature distribution in latitude. According to the horizontal scale, climate can be divided into macroclimate, mesoclimate and microclimate. Macroclimate refers to global and regional climate, such as tropical rain forest climate, Mediterranean climate, polar climate and plateau climate. Moderate climate refers to the climate of smaller natural areas, such as forest climate, urban climate, mountain climate and lake climate; Microclimate refers to a small range of climate, such as the atmosphere close to the ground and the climate under a small range of special terrain (such as mountains or valleys).
Under the influence of latitude, land and sea distribution, atmospheric circulation, topography, ocean currents and other factors, the world climate can be roughly divided into the following types:
(1) tundra climate: long and cold in winter and short and cold in summer;
(2) Coniferous forest climate in sub-cold zone: mild in summer and cold in winter;
(3) temperate monsoon climate, with warm summer and mild winter;
(4) Temperate grassland climate: hot in summer and cold in winter;
5. Temperate desert climate: hot and dry in summer and cold in winter;
[6], subtropical rainforest climate;
Once, the subtropical monsoon climate;
(8) Tropical desert climate: high temperature and little rain;
(9) Tropical grassland climate: rainy in warm season and dry in cool season;
⑽ Tropical rain forest climate: high temperature and high humidity;
⑾. Mountain climate: vertical change from the foot of the mountain to the top of the mountain;
⑿ Coniferous forest climate in sub-frigid zone: winter is long and cold, and summer is short and warm;
(13) temperate maritime climate: warm in winter and cool in summer, with small annual temperature difference;
14. Subtropical Mediterranean climate: mild winter with little rain and hot summer with little rain.
Climate change has an important impact on human beings and natural systems. Because ecosystems and human society have adapted to today's and recent past climate, it will be difficult for people to cope with these changes if they adapt too fast. For many developing countries, this may have a very harmful impact on the basic living standards of human beings (housing, food, drinking water and health). For all countries, the increasing frequency of extreme weather and climate events will increase the risk of weather disasters. Climate change has both positive and negative impacts on China's economy and society, some of which are actually irreversible, so we should pay more attention to the negative impacts. According to statistics, from 1950 to 2000, especially after 1990, the economic losses caused by meteorological disasters increased sharply. There are two reasons, on the one hand, the increase of extreme weather events, on the other hand, the increase of China's overall economic volume, so the absolute value of economic losses has obviously increased.
The impact of climate change on agriculture is negative. It is predicted that by 2030, China's three major crops, rice, corn and wheat, will mainly reduce production except winter wheat. Climate change also has a great impact on water resources. Global warming accelerates the water cycle and increases the spatial heterogeneity of precipitation. Climate change also has an impact on major projects, such as the increase in precipitation in the upper reaches of the Yangtze River, which will lead to an increase in the frequency of geological disasters and have a certain impact on the safe operation of the Three Gorges Reservoir. In addition, climate change will also affect the Qinghai-Tibet railway and highway, greatly increasing the investment in railway and highway operation and maintenance.
Like the whole world, China's climate and environment have also undergone tremendous changes. Climate warming goes far beyond the general climate and environmental problems, and has brought a very serious threat to the economic and social development of China, and this threat will continue and intensify. Scientific and technological circles should pay special attention to climate change, actively take adaptation and mitigation measures, and constantly improve the level and level of climate system, ecology and environmental protection. This is an important content of fully implementing Scientific Outlook on Development and building a harmonious socialist society, and it is also the common aspiration of the government, the public and scientists.
The coldest place in winter and the hottest place in summer in China.
The coldest place in China in winter is Mohe Town, Heilongjiang Province. 65438+ 10 The monthly average temperature is -30.6 degrees. The coldest place has an extreme minimum temperature of 52.3 degrees. This is the lowest temperature in the existing meteorological records in China. The hottest place in China in summer is Turpan in Xinjiang. The average temperature in July is 33 degrees, so it is called "Huozhou". The extreme maximum temperature there once reached 49.6 degrees. This is the lowest value in the existing meteorological records in China. The average temperatures in Chongqing, Wuhan and Nanjing, known as the "three stoves", were 28.6, 29.0 and 28.2 respectively in July. Compared with Turpan in Huozhou, we have to admit defeat.