Problems caused by global warming, geographical perspective. The more detailed the better.

No one can say exactly how serious the harm caused by releasing more greenhouse gases such as carbon dioxide into the atmosphere will be in the future. Scientists are estimating the harm caused by climate change. According to the current technical level, the mechanism of the formation and digestion of carbon dioxide in the atmosphere can only be clarified in 24, so that we can find out how the greenhouse effect is produced. Only in 26 can the sea level rise caused by global warming be accurately predicted. However, it will not be until 25 to truly understand all this. Obviously, scientists and politicians will not wait for further results before taking preventive measures. The current observation and research results should be made known to the public, so that people will not have to swallow their own bitter fruit 5 years later.

the greenhouse effect has been working since the formation of the earth. If there is no greenhouse effect, the earth's surface will be extremely cold, the temperature will drop to MINUS 2℃, the ocean will freeze and life will not form. Therefore, we are not faced with the problem of whether there is a greenhouse effect, but the problem that human beings emit a large amount of greenhouse gases into the atmosphere by burning fossil fuels, which leads to a sharp change in the greenhouse effect and the earth's climate.

what impact will the greenhouse effect have? Due to the burning of fossil fuels and deforestation, the concentration of carbon dioxide in the earth's atmosphere has increased. Due to the greenhouse effect of carbon dioxide and other gases, the global average ground temperature has increased by about .3-.6℃ in the past 1 years, and it is estimated that it will increase by 1-3℃ in 23.

When the average temperature in the world rises by 1℃, great changes will occur: sea level will rise, glaciers in mountainous areas will retreat, and snow-covered areas will shrink. As the global temperature rises, it will lead to unbalanced precipitation, with precipitation increasing in some areas and decreasing in others. For example, the Sahel region in West Africa has been seriously arid since 1965; Since 1965, the precipitation in North China has decreased year after year. Compared with the 195s, the precipitation in North China has decreased by 1/3 and the water resources by 1/2. The area affected by drought in China is about 4 million mu every year. In normal years, irrigation areas in China are short of water by 3 billion cubic meters every year, and cities are short of water by 6 billion cubic meters. When the average temperature of the whole world rises by 3℃, human beings will be unable to recover, and the world will be short of food. Due to the rising temperature, the global sea level has been rising at a rate of 1-2 mm every year in the past 1 years. It is predicted that the sea level will continue to rise by 3-5 cm by 25, which will flood a large number of low-lying land along the coast. In addition, due to climate change, climate disasters such as drought, flood and low temperature have intensified, resulting in economic losses of more than tens of billions of dollars every year around the world.

Glacier Melting

In recent years, people have observed the melting of glaciers in the Alps from Patagonia to Switzerland due to the emission of "greenhouse" gases and the generally recognized greenhouse effect. In South Asia, the question is not whether glaciers are melting, but how fast they are melting. Although many adverse effects of global warming may not become very serious until the end of the 21st century, meltwater from glaciers in Nepal, India, Pakistan, China and Bhutan may soon cause people trouble.

A research report of the International Ice and Snow Committee (ICSI) points out: "The glaciers in the Himalayas are retreating faster than any other in the world. If the current melting rate continues, it is very likely that these glaciers will disappear before 235. " Saeed Hasenen, head of the International Snow and Ice Commission, said: "Even if the glacial meltwater dries up in 6 to 1 years, the scope of this ecological disaster will be shocking."

Glaciers in the eastern Himalayas located in the Ganges River basin are the most serious, and those glaciers that are distributed on the "roof of the world" from Bhutan to Kashmir retreat the fastest. Take the 3-mile-long Barnak Glacier as an example. This glacier is one of many glaciers formed by the collision between the Indian subcontinent and the Asian continent 4-5 million years ago. Since 199, it has retreated by half a mile. After the severe sub-arctic winter in 1997, scientists had expected this glacier to expand, but it retreated further in the summer of 1998.

Diseases are rampant

Paul Perseverstein of the Institute of New Diseases and Recurrent Diseases of Harvard University noticed that plants also move with the snow line, and plants on mountain peaks all over the world are moving up. With the warming of mountain peaks, the environment at higher altitudes is more and more conducive to the survival of mosquitoes and microorganisms such as plasmodium they carry.

Tropical infectious diseases such as West Nile virus, malaria and yellow fever have broken out in Florida, Mississippi, Texas, Arizona, California and Colorado in the United States since 1987, which has repeatedly confirmed experts' scientific inference that some tropical diseases will spread to colder regions due to climate warming.

New Ice Age

Another research result about global warming is even more surprising. Due to the melting of the Arctic ice sheet, increasing rainfall and changing wind types, a large amount of fresh water is flowing into the North Atlantic Ocean, causing damage to the Gulf Stream, thus cutting off the North Atlantic Stream. It is these warm currents that bring warm surface water from the Caribbean to the northwest of Europe and make Europe form a warm climate. Once the North Atlantic warm current is cut off due to global warming, the temperature in northwest Europe may drop by as much as 5-8℃, and Europe may face a new ice age!

This study was made by the Scottish Marine Laboratory in Aberdeen, which analyzed more than 17, seawater salinity measurements from the waters between the Netherlands and the Faroe Islands since 1893. In the past 2 years, the salinity and concentration of deep seawater flowing to the south have become smaller and smaller, which indicates that more fresh water has flowed into the region from the northern Atlantic. These new data fully proved the computer model designed by German scientists about three years ago for the first time.

The content of carbon dioxide in the atmosphere is rising sharply, and the world population will reach 1 billion before 25. "Our world is moving towards replacing the existing free natural resources with man-made facilities," said David Tillman of the University of Minnesota. However, we haven't mastered the knowledge about natural ecosystems. In the Permian extinction 245 million years ago, 96% of species died out. Later, with the emergence of many new species, the earth finally recovered its rich population, but this process has gone through 1 million years. Wilson said: "Some people think that nature will revive everything that human beings have destroyed." As the saying goes, "As long as there is enough time, everything can come into being." Perhaps nature can really restore everything, but this long process is meaningless to modern human beings anyway.

Mark Twain once said that the most touching feature of the weather is its variety. More than a century later, we are still trying to accurately predict the weather, but we have little effect in controlling the climate; However, the damage to the environment is unprecedented.

Ecology

First of all, global warming leads to sea level rise and precipitation redistribution, which changes the current world climate pattern; Secondly, global warming affects and destroys the biological chain and food chain, bringing more serious natural consequences. For example, there is a migratory bird that flies from Australia to the northeast of China for the summer every year. However, due to global warming, the temperature in the northeast of China rises and the summer is prolonged, so the time for this bird to leave the northeast and return to the northeast is correspondingly delayed. As a result, a pest eaten by this migratory bird flooded and destroyed a large area of forest. In addition, extreme events related to the environment have increased, such as drought and flood.

Politics

Limiting the emission of carbon dioxide is equivalent to limiting the consumption of energy, which will definitely have a restrictive impact on all countries in the world. Whether to reduce emissions in developing countries or in developed countries has become the focus of discussion among countries. The greenhouse gas emissions of developing countries are increasing, and the problem of "emission reduction" after 213 will inevitably focus on developing countries. The scientific problem of preventing global warming will inevitably lead to the problem of "North-South relations", thus making the climate issue an international political issue.

climate

global warming has increased precipitation in mainland China, especially in middle and high latitudes, and decreased precipitation in some areas such as Africa. The frequency and intensity of extreme weather and climate events (El Nino, drought, floods, thunderstorms, hail, storms, high temperature weather and sandstorms, etc.) have increased in some areas.

Ocean

With the global temperature rising, the amount of water vapor evaporated in the ocean has greatly increased, which has aggravated the warming phenomenon. The reduction of the overall thermal capacity of the ocean can inhibit global warming. In addition, because the ocean releases excessive carbon dioxide into the atmosphere, the real culprit is the plankton community in the ocean.

crops

global warming has both advantages and disadvantages on crop growth. First, global temperature changes directly affect the global water cycle, causing droughts or floods in some areas, resulting in reduced crop production, and excessive temperature is not conducive to seed growth. Second, the increase of precipitation will actively promote crop growth, especially in arid areas. The increase of carbon dioxide content accompanied by global warming will also promote the photosynthesis of crops, thus increasing the yield.