What are the factors that human activities can affect the climate? Give examples.

At present, scientists all over the world know that more than 90% of the current climate change may be the responsibility of mankind, and the decisions and choices made by mankind today will affect the trend of climate change. Today, the earth is hotter than it was in the past two thousand years. If the situation continues to deteriorate, the temperature of the earth will climb to the highest level in two million years by the end of this century. For one hundred years, mankind has been relying on fossil fuels such as oil and coal to provide energy for production and life. Carbon dioxide and other greenhouse gases emitted by burning these fossil fuels are the main reasons for enhancing the greenhouse effect and triggering global climate change. About 1/5 of greenhouse gases are emitted due to destroying forests and reducing the ability to absorb carbon dioxide. In addition, some special industrial processes, agriculture and animal husbandry will also have a little greenhouse gas emissions.

In China, coal occupies a dominant position in the total energy consumption. From 1979 to 2005, the average proportion of coal resource consumption in the total energy consumption was 72.4%. In the relative changes of various energy consumption, although the proportion of coal in the total energy consumption shows a slow downward trend, its absolute consumption is on the rise. At present, coal consumption accounts for about 67%, and China's energy efficiency is not high, so it is unsustainable to rely on coal for development. Faced with the increasingly serious problem of global warming, people have only one choice: they must take immediate action.

1. Global warming leads to the melting of Himalayan glaciers, and human water resources are in urgent need. Due to global warming, Himalayan glaciers are rapidly "consuming". In April, 2007, the Greenpeace expedition photographed the grim situation of melting glaciers in the Himalayas, and the situation was very critical. Glacier is the largest fresh water reservoir on the earth. The data show that since the beginning of records, global glaciers are melting at the fastest speed in more and more areas of the world. In the 1990s, the global glaciers showed an accelerated melting trend, and the rate of melting and shrinking of glaciers was accelerating, which meant that millions of people would face the threat of floods, droughts and reduced drinking water. Glaciers on the Qinghai-Tibet Plateau, known as the "Water Tower of Asia", are the source of many major rivers in China and even Asia, and the water problem of hundreds of millions of people is also closely related to them. Global warming caused by human burning a lot of fossil fuels has accelerated the retreat of glaciers. Himalayan glaciers are melting faster than any other region in the world. According to the recent report of the United Nations Intergovernmental Panel on Climate Change (IPCC), according to the current global warming trend, 80% glaciers in the Himalayas will melt in less than 30 years. This will undoubtedly add insult to injury to the increasingly severe water shortage in China. Greenpeace has visited Mount Everest twice in the past two years. On April 20th this year, a five-member Himalayan expedition from Greenpeace went to the Himalayas to witness the melting of Himalayan glaciers. Compared with the photo of 1968, the image of the Rongbu Glacier on Mount Everest taken this time shows that the ice tower forest recedes sharply and becomes sparse and short. 2. Extreme Climate Blizzard, rainstorm, flood, drought, hail, lightning, typhoon ... Extreme climate has visited the earth very frequently in recent years, all of which are related to the global climate change background. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) released in 2007 shows that "since the 1970s, droughts have occurred in a wider range, longer duration and more serious, especially in tropical and subtropical regions." "In the past 50 years, extreme high temperature and low temperature have undergone extensive changes. All-weather low temperatures and frosts have become less frequent than before, while all-weather high temperatures and heat waves have become more common. " The frequency and intensity of extreme weather and climate events have increased, which has brought great harm to people's lives and property safety. Over the past half century, there have been more and more heavy rains in southern areas such as the middle and lower reaches of the Yangtze River, while the drought in northern provinces has been expanding. In recent years, a rare severe drought has hit many southern provinces, and typhoons such as Sang Mei and Sao Paulo have frequently hit the southeast coastal provinces, with constant alarm bells. In recent years, the area affected by crops in China has reached 50 million hectares every year, and 43 million tons of grain have been lost due to disasters. Every year, 400 million people are affected by major meteorological disasters, resulting in an average economic loss of more than 200 billion yuan. In 2007, China's climate was abnormal, the severity of rainfall was uneven, extreme weather events occurred frequently, and disasters occurred in many places and regions. Some areas have been repeatedly hit by disasters, and rainfall, floods, droughts and disasters in some areas have exceeded historical records, resulting in direct economic losses of 236.3 billion yuan. The lens of the media recorded the devastating disasters such as the spring drought in Hainan, the flood in Huaihe River and the typhoon in Leizhou Peninsula. Third, the reduction of grain production Global warming leads to the reduction of grain production, because global warming brings drought, water shortage, sea level rise, floods, heat waves and drastic temperature changes, which will destroy the world's grain production. The grain belt in most parts of Asia and the United States will become dry. In some arid agricultural areas, such as sub-Saharan Africa, as long as global warming brings a slight temperature rise, food production will be greatly reduced. Small changes in global warming will have unexpected consequences on food production. The sensitivity of rice to sudden changes in temperature is an example. According to the research of the International Rice Research Institute, if the minimum temperature at night rises by 1 Celsius (1.8 Fahrenheit), the rice harvest will decrease by 10%. It is worth noting that rice is the main food for more than half of the world's population, so small changes in global warming will have a far-reaching impact. For China, global warming may increase the instability of agricultural production, and high temperature, drought, pests and other factors may lead to reduced grain production. If no measures are taken, it is estimated that by 2030, the planting production capacity of China may decrease by 5% to10% as a whole; Wheat, rice and corn are mainly declining, and by the second half of 2 1 century, the yield can be reduced by 37% at most. At the same time, global warming will affect the quality of crops, such as soybeans, winter wheat and corn. Global warming and rising temperature will also lead to the expansion of agricultural diseases, pests and weeds, the extension of damage time and the aggravation of crop damage, thus increasing the application of agriculture and herbicides. In addition, global warming will aggravate the instability of agricultural water resources and the contradiction between supply and demand. In a word, global warming will seriously affect China's long-term food security. In March 2007, Hainan, a tourist resort with four seasons like spring, suffered a severe spring drought. As of the beginning of April, the drought-affected area of crops in Hainan Province was 654.38+0.549 million mu; Four15 reservoirs dried up, and the number of people suffering from drinking water drought reached 654,380+099,900. Greenpeace visited Hainan and witnessed the profound impact of extreme climate on local agriculture. Fourth, sea level rise In Kiribati, a South Pacific island country, Pita Meanke from Bettio Village stood by a tree. The huge wave washed away the anti-Boti and destroyed his home. "Maldives is just one of the small countries. We have no ability to change the world. But the decision made here will have a huge impact on my people and will change world history. " Speech by H.E. Maumoon Abdul gayoom (Maldives) at the Third Conference of the Parties to the Kyoto Framework Convention on Climate Change. Island countries are not alone in worrying about rising sea levels. More than 70% people in the world live in coastal plains; Among the top 15 cities in the world, 1 1 is located along the coast or at the estuary. According to the Special Report on Emission Scenarios (SRES) of the Intergovernmental Panel on Climate Change, from 1990 to 265438+1980s, the global sea level will rise by an average of 22 to 34 centimeters. In the past 30 years, the sea level along the coast of China has generally risen by 90 mm, which is faster than the global average. It is worth noting that the global sea level remains unchanged. Due to the influence of seawater circulation or wind pressure, the sea level in different areas will be different. Therefore, when evaluating the impact of sea level rise, we also need to pay attention to the impact of storms, waves and spring tides. Even a slight sea level rise can cause serious damage. For example, some low-lying coastal cities and villages will be affected by flooding and serious damage in coastal areas, coastline erosion, fresh water pollution, flooding in coastal wetlands and islands and rising salinity in estuaries. Some resources that are particularly important to the population of islands and coastal areas, such as beaches, fresh water, fisheries, coral reefs, atolls and wildlife habitats, will be threatened. Faced with the threat of flood, seawater intrusion, land erosion and strong tropical storms, the densely populated and economically developed urban agglomerations of Yangtze River Delta, Pearl River Delta and Yellow River Delta are the most vulnerable areas. V. Extinction of Species Albino Coral Reef on the Great Barrier Reef "Most endangered species on the planet-about 25% of mammals and 12% of birds-may be extinct within a few decades. This is because climate change has affected the forests, wetlands and pastures where they live, and human development has also prevented them from migrating to other places. " Every species in the United Nations Framework Convention on Climate Change has its own unique ecological position, and evolution allows them to live in this unique position-living in its special "residence" and specific living environment (including temperature and other animals and plants). Some creatures have strong adaptability, or "flexibility". For example, mice and dogs can live in very difficult environments, while koalas can only live where there are eucalyptus trees. Human activities lead to climate change, and the temperature, rainfall and sea level rise, which destroys the habitats of some organisms, and the destruction speed is faster than the migration speed of organisms. The fourth assessment report issued by the United Nations Intergovernmental Panel on Climate Change (IPCC) IPCC)2007 pointed out that climate change will lead to a large number of species extinction in the next 6 to 70 years. What is certain now is that the climate is related to the extinction of some frogs, and this is just the tip of the iceberg. The risk of species extinction caused by climate change will be greater than five serious species extinctions in the history of the earth. The only way to prevent it is to reduce emissions rapidly in the next few decades. Time is running out to save living things.

6. Air Pollution Coal-fired power plants and transportation systems cause air pollution. Saving energy and using public transportation as much as possible can reduce air pollution. Air pollutants include sulfur dioxide (SO2), nitrogen oxides (nitrogen oxides), carbon monoxide (CO), ozone and photochemical oxidants, inhalable suspended particles and so on.

According to the website of planetearth.nerc.ac.uk, recent research has found that the deep sea is being seriously damaged by human activities, and the situation is getting worse. Scientists call for the protection and management of deep-sea ecosystems.

The deep sea refers to the sea area with a depth of less than 200 meters, covering an area of 360 million square kilometers, accounting for about half of the earth's surface. It is the largest ecosystem and huge wilderness on the earth. The average depth of the deep sea is about four kilometers, and the depth of the Mariana Trench, the deepest on earth, is close to 1 1 kilometer.

For hundreds of years, people have been using the deep sea to dump garbage, but now the biggest threat facing the deep sea comes from climate change. In fact, people know little about the deep sea, which is rich in resources, such as fish, minerals, submarine oil and natural gas.

However, how do human activities affect the deep sea? Professor Paul from ocean centre, England? Paul taylor said: "This is a difficult question because we know too little. But as early as the 1980s, people began to develop deep-sea oil on a small scale. "

In order to evaluate and explain the diversity, regionality and richness of marine life, 20 researchers from different countries set up a marine life survey project team, which lasted 10 years. Scientists analyzed the past, present and future impacts of human activities, especially the impacts of waste treatment, development and climate change on deep-sea habitats.

Taylor said: "People usually only regard the deep sea as a large water body, but it is actually a huge ecosystem with valleys, mountains, volcanoes and plains, and the situation is complex and changeable."

Plastic, glass and metal garbage are the most common types of garbage in the deep seabed. The researchers said: "From 1973 to 1978, more than 387,000 tons of medical waste were dumped into the Puerto Rico trench." Although the dumping of wastes, such as sewage, drugs and low-level radioactive substances, remains a problem.

But the main danger at present is deep-sea development. Due to the development of technology, people can exploit seabed oil and natural gas and catch many fish. Coupled with climate change, the deep sea is facing "great and urgent challenges".

Researchers say that climate change will surpass mining activities and become the most destructive factor, which will aggravate the acidity of the ocean and lead to chalking of coral and biological bones such as starfish, sea urchins and sea cucumbers.

At present, it is more difficult to strengthen the management of the deep sea, because activities such as dumping waste, fishing and climate change have changed the deep sea far beyond the research scope of scientists.

Taylor said: "The fastest actor in deep-sea activities is the resource developer. Although we should legislate first, then carry out scientific research and then develop. But scientists, managers and legislators have fallen behind to some extent. "

The researchers said: "To implement regulatory measures on the high seas (accounting for 64% of the global ocean area), it is necessary to review and amend the existing United Nations Convention on the Law of the Sea to provide broader protection." (He Jiao)

Source: People's Network-Environmental Protection Channel