What's the temperature of the earth now?

At present, the average temperature of the earth is about 15℃. The Cretaceous heat wave reached a higher temperature in the Cretaceous period about 1 100 million years ago. At that time, the average temperature of the earth was 22.8℃, which was more than 7℃ higher than now, and all the ice and snow at the poles of the earth melted. The reason why the climate is so hot is that a large amount of carbon dioxide produced by volcanic eruption has caused a strong greenhouse effect. In addition, due to the redistribution of the continent caused by plate drift, the heat accumulated near the equator can be transported to all parts of the earth through the ocean warm current. Cenozoic continuous cooling in the Cenozoic (600-500 million years ago), the earth's temperature continued to drop. This cooling seems to be due to the drift of continental plates. The huge newly rising mountains fix carbon dioxide in the rocks in the form of silicate, so the carbon dioxide in the atmosphere decreases, the greenhouse effect weakens and the earth cools. Ice age and Milankovic cycle in the recent 6.5438+0 million years, due to the change of the earth's orbit, the phenomenon of alternating ice age and warm period appeared. Astronomer Milankovic pointed out that the earth's climate change has three astronomical cycles: every 20,000 years, the earth tilts from the axis for one cycle (called precession); Every 40,000 years, the intersection angle between the ecliptic of the earth and the equator changes for a period; Every 654.38+ million years, the eccentricity of the earth's orbit changes by one cycle. The last Great Ice Age The last Great Ice Age, called Quaternary Ice Age, began 80,000 years ago and reached its peak 6,543.8+0.8 million years ago. Now Alaska, Canada and the northern United States are covered by a whole piece of ice, and the thickness of the ice is nearly 1000 meters. In Europe, ice has pushed to Hamburg and Berlin today. But in the southern hemisphere, ice moves much slower. Later, the temperature rose rapidly, and the ice began to melt about1.20 thousand years ago. This is how the last Great Ice Age ended. The cold period of the new fairy tree was about 1. 1 ten thousand years ago, but the earth just left the last ice age and suddenly returned to the ice age. This is the famous cold period of the new fairy wood, which lasted about 1000 years, and was caused by the sudden interruption of the deep-water conveyor belt in the North Atlantic. The most suitable climate is in the first few thousand years after the cold period of the new fairy tree. The climate of the earth used to be very hot. 9000~5000 years ago. The temperature of the earth has risen by several degrees Celsius, forming the so-called "climate optimum period". The Little Ice Age 500 years ago was from 1400 to 1500, and the earth's temperature suddenly dropped again, which was called the "Little Ice Age". From 1434 to 1435, there was continuous snowfall in Britain for 40 days. /kloc-in the winter of 0/608, all the livestock in Britain were frozen to death, and the whole lake Constance was frozen. 1789 In winter, almost all rivers in Europe were frozen. It was not until the second half of the19th century that glaciers began to recede. Recent changes In the last century 150 years, the earth began to get hot rapidly. During the period of 1850 ~ 1980, the average temperature rose by 0.6℃, of which about 0.26℃ was related to the increase of solar activity intensity, and the rest was due to the influence of human activities. Current Climate Global Warming In the last 20 years, the pace of global warming has suddenly accelerated, especially compared with 195 1 ~ 1980, the average temperature of the earth has increased by about 0.3℃. But this phenomenon is not global synchronization. In some areas, such as the Mediterranean, the temperature rises even higher than other areas. This warming has many impacts on climate and animal habitats, such as tropical temperate zone, desertification in tropical areas, melting of polar ice floes and ice sheets, and migration of tropical species and diseases to mid-latitude areas. The movement of the rain area the whole rain area of the earth is moving. Since 1980, the rainfall of 50 ~ 60 north latitude in Europe has increased. But the rainfall in the Mediterranean is much less. There is little rain in summer, but it often rains cats and dogs, and there are often storms. However, in recent years 10, the autumn rainfall increased, leading to an increase in flood events. Since 1950, there have been five major floods, three of which occurred in the 1990s. The abnormal increase of extreme weather and climate is a prominent manifestation of climate extremes. There are more floods than in the past (1 9th century, China experienced1flood every 20 years on average, while in the 20th century, there were 9 ~ 10/flood every 20 years on average), and the El Ni? o phenomenon is more frequent, stronger and longer lasting (1997 ~/kloc-). Major storms in northern Europe are also more frequent (five in the 1990s alone). Finally, there is a strong storm. The torrential rain in the summer of 2002 (satellite images showed disastrous bad weather on August 10) caused the worst flood in the history of Central and Eastern Europe in the past 100 years. The air has changed. Due to human activities, in recent decades, more and more substances have been discharged into the atmosphere, which has changed the chemical composition of the air and had a negative impact on the climate and animal habitats. In big cities, the density of dust, nitrogen oxides and ozone is very high, which makes the air quality worse. At the same time, the enhancement of heat island effect increases the number of severe storms, and the emission of chlorofluorocarbons destroys the ozone layer that protects us from ultraviolet rays. The future climate depends on the future climate of greenhouse gases, or the climate of 2 1 century, which is related to the emission of greenhouse gases, especially carbon dioxide. According to the future economic development and different environmental protection measures taken in the next few years, the climate will have different conditions. It is predicted that the concentration of carbon dioxide in the atmosphere will double by the end of this century. The consequences of environmental pollution are mainly manifested in three aspects: the increase of average temperature, the disturbance of atmospheric circulation and climate stability. If carbon dioxide doubles, the increase of greenhouse gas concentration will enhance the greenhouse effect in the next few decades, and the average temperature of the earth will continue to rise. If the concentration of carbon dioxide in the atmosphere doubles by the end of this century, the average temperature of most land will rise by 4~5℃. In 2030, the global average temperature will rise by 1~2℃. If the concentration of carbon dioxide increases rapidly, the global average temperature will rise by 1~2℃ by 2030. By 2080, the average temperature may rise by 1.5~3℃, and the Mediterranean region may rise by 3.5~4℃. The increase of average temperature not only makes the daytime hotter, but also makes the heat wave more intense and lasting, even in autumn and winter. 1 year ago-reporting, adding/viewing opinions (0) can also be entered in 300 words. Please enter the verification code in the above picture. Letters are case-insensitive.