Specifically, what is climate change?
Climate change refers to the 1 or both of the mean and deviation values of climate with statistical significance over time. The rise and fall of the average value indicates the change of the average climate state; The increase of deviation indicates that the instability of climate state increases and the climate anomaly becomes more obvious. In the first paragraph of the United Nations Framework Convention on Climate Change, "climate change" is defined as: "After a long period of observation, except for natural climate change, human activities directly or indirectly change the composition of the global atmosphere." Therefore, the United Nations Framework Convention on Climate Change distinguishes "climate change" that changes the atmospheric composition due to human activities from "climate variability" attributed to natural causes.
What are the causes of climate change? The causes of climate change may be natural internal processes, external coercion, or man-made continuous changes in atmospheric composition and land use. There are both natural factors and human factors.
Human factors are mainly caused by human activities since the industrial revolution (especially economic activities in the process of industrialization in developed countries). The greenhouse gases emitted by human activities, such as burning fossil fuels, deforestation and land use change, lead to a significant increase in atmospheric greenhouse gas concentration and enhanced greenhouse effect, thus causing global warming. According to the research report of Oak Ridge Laboratory in the United States, since 1750, the world has emitted more than one trillion tons of carbon dioxide/kloc-0, of which developed countries account for about 80%.
What are the international views on climate change? Although there are still some uncertainties, most scientists still think it is necessary to take preventive measures in time. Global climate change has aroused widespread concern in the international community. With the formulation of the United Nations Framework Treaty on Climate Change, the international community's measures to deal with climate change have gradually taken shape. 1979 the first world climate conference called for climate protection; 1992 adopted the United Nations Framework Convention on Climate Change, which established the principle of "common but differentiated responsibilities" between developed and developing countries, and defined its action framework, and made efforts to stabilize the concentration of greenhouse gases in the atmosphere at a certain level, thus preventing human activities from having a "negative impact" on the climate system; The Kyoto Protocol adopted in 1997 (hereinafter referred to as "the Protocol") set quantitative emission reduction targets for developed countries from 2008 to 20 12. The Bali Road Map reached from 5 to 38 June 2007+February decided to start negotiations on strengthening the implementation of the United Nations Framework Convention on Climate Change and the Protocol respectively, and to hold the Conference of the Parties in Copenhagen from 5 to 38 June 2009+February.
Up to now, UNFCCC has received ratification, acceptance, support or amendment documents from 65,438+085 countries, and successfully held six sessions of the Conference of the Parties, all of which were attended. Although the parties have not yet reached a consensus on the measures to comprehensively control climate change, global climate change will bring immeasurable losses to people. The concept that climate change will make mankind pay a huge price has been widely accepted in the world and has become a global environmental problem that has been widely concerned and studied.
History of Climate Change in China
1973, Zhu Kezhen put forward the basic situation of periodic climate fluctuation in China. He believes that in the middle of 2000, the Han Dynasty was a warm period, and soon after the Three Kingdoms began, the climate became cold, which was postponed until the early Tang Dynasty. After the end of the Tang Dynasty, the climate became cold again, and gradually entered the Little Ice Age in the15th century, showing a structure of two peaks and three valleys, until the climate became warmer in the early 20th century and the Little Ice Age ended. The Han Dynasty and the Tang Dynasty were warm periods when the annual average temperature was about 2℃ higher than that of modern times. The research results have been widely used in climatology and historical geography. But in recent years, due to the discovery of new materials and the improvement of research methods, many scholars have supplemented Zhu Kezhen's work. Among them, Zhu and others believe that since 2000~3000, the climate change in the historical period of China has experienced the following stages:
(1) The climate in the Western Zhou Dynasty (1 1 century to the middle of the 8th century BC) was cold and dry; (2) The warm and humid climate from the Spring and Autumn Period to the early Western Han Dynasty (from the middle of the 8th century BC to 1 century BC); (3) the cool and dry climate from the late Western Han Dynasty to the Northern Dynasty (65438 BC+the middle of the 0 th century to the 6 th century); (4) The warm and humid climate in Sui and Tang Dynasties (7th-8th century); (5) The cool and dry climate from the late Tang Dynasty to the Northern Song Dynasty (from the 9th century to 1 1 century); (6) The dry and wet climate in the pre-Jin period (12nd century); (7) The cool and dry climate at the end of Jin Dynasty and the beginning of Yuan Dynasty (13 and the first half of 65438+4th century); (8) During the Ming and Qing Dynasties (1the second half of the 4th century to the beginning of the 20th century), the climate was cold and dry.
Later, many geographers made further amendments to the climate change in China, but the general trend was roughly the same.
In the historical period, the climate not only fluctuates periodically in temperature, causing temperature changes, but also changes in humidity. Generally speaking, warm period and wet period, cold period and dry period are corresponding, but each cold and warm period has wet and dry fluctuations, which cannot be generalized. Zhu and others believe that the change of temperature is faster than that of precipitation, and the change of precipitation is greater than that of temperature. In the historical period, the fluctuation of climate change of temperature and humidity has obvious correlation, but they are not completely synchronized.
Climate change in 2 1 century-worry and reflection coexist
The decline of ancient civilization warns us.
Isolated in the Pacific Ocean, Easter Island is one of the most remote areas on earth. The ancient silent colossus of La Nororo Laco crater is the only witness left by ancient civilization. In the over-exploitation of environmental resources by human beings, the ancient civilization disappeared. In the endless struggle between tribes, predatory logging makes large forests disappear from the earth quickly, soil and water are eroded continuously, birds are on the verge of extinction, and food and agricultural systems that maintain human survival are repeatedly destroyed. Disaster is imminent, the alarm bell has sounded, but it is too late and the collapse crisis is inevitable.
The story of Easter Island is frightening. It warns us that if we don't treat ecological resources well, it will bring bad consequences to the earth. Climate change in 2 1 century is a global extension of this story. The difference is that on Easter Island, an unpredictable and uncontrollable crisis destroyed people, but today, ignorance is by no means our excuse. We have the evidence and the ability to avoid the crisis, and we know the consequences of business as usual.
1963, the most severe cold war period after the Cuban missile crisis, President John F. Kennedy once pointed out: "On this planet, human beings are inseparable and have the same vulnerability, which is an indisputable fact of our time." What enveloped the world at that time was the ghost of a nuclear holocaust. It is an indisputable fact that 40 years later, the crisis of climate change is hanging over us.
Climate change brings double disasters to mankind. Climate change directly threatens human development. People all over the world are affected by climate change, but the poorest people will bear the brunt and suffer the most direct damage, and the lack of resources often makes them helpless. This disaster is not far away from us. Today, this disaster has become obvious, which has slowed down our progress in achieving the Millennium Development Goals and aggravated the inequality within and between countries. If we ignore this point, human development will fall into the abyss of retrogression in the 2 1 century. Climate change will bring disaster to the future. Just like the nuclear confrontation during the Cold War, climate change threatens not only the poor, but also the whole planet and our future generations. At present, we are taking a road of no return, which will inevitably lead to ecological disaster. The speed, exact time and influence of global warming are still unknown, but the disintegration of the earth's huge ice sheet is accelerating, the ocean is warming, the rainforest system is collapsing, and other consequences have become a reality. These dangers may lead to a series of consequences, completely changing the human geography and physical geography of our planet.
Our generation has the ability and responsibility to change this consequence. The immediate danger is seriously tilting towards the poorest countries and their most vulnerable groups in the world. However, there is no harbor that is always calm. Although rich countries and their people are not directly facing the coming disasters, it is difficult to avoid the impact of these disasters in the end. Therefore, taking measures to mitigate climate change in advance will be the basic guarantee for all mankind (including the descendants of developed countries) to avoid future disasters.
The core problem of climate change is that the earth's ability to absorb carbon dioxide and other greenhouse gases is seriously affected. Human life has exceeded the recovery capacity of the environment, and in terms of ecology, human beings have owed huge debts that future generations cannot repay.
Climate change urges people to think about human interdependence from a new perspective. No matter what separates us, human beings enjoy the earth, just as they share their island with the islanders on Easter Island. The ties connecting human society have no national boundaries and are not restricted by generations. No country, big or small, can ignore the fate of others and forget the consequences of today's actions for future people.
Our future generations will measure our moral values by our response to climate change. This reaction will prove how today's political leaders can take action to fulfill their commitments, eradicate poverty and build a more inclusive world. If our actions further marginalize most human beings, it is contempt for social fairness and justice between countries. Climate change has also raised a sharp question for us-how to treat our relationship with future generations? Action is a barometer, reflecting our commitment to intergenerational social fairness and justice, and it is the basis for future generations to judge our behavior.
There are some encouraging signs. A few years ago, climate change skepticism prevailed. Climate skeptics have been generously sponsored by big companies, and their theories have been widely publicized by the media. Some governments have listened to their views, thus misleading the public. Today, every honest environmental scientist thinks that climate change is a grim fact, and climate change is related to carbon dioxide emissions. Governments around the world also think so. The consistency of science does not mean that the debate on the causes and consequences of global warming is over: the science of climate change studies the possibility, not the inevitability, but at least today's political debate is based on science.
However, there is a big gap between scientific evidence and political action. So far, most governments have failed to meet the requirements of climate change and emission reduction. Recently, the Intergovernmental Panel on Climate Change released its fourth assessment report. Most governments responded by acknowledging that there is no doubt about climate change and urgent action is needed. The Group of Eight held successive meetings and reiterated the need to take concrete measures to deal with climate change. They admitted that the ship seemed to be heading for the iceberg, which was an ominous sign. Unfortunately, they did not take drastic measures to determine a new greenhouse gas emission route.
Time is running out, which is an indisputable fact. The challenge of climate change must be solved in 2 1 century. At present, there is no immediate technology. Although the time span is very long, it must not be an excuse for perfunctory and indecision. In order to find an effective solution, governments must solve the problem of inventory and flow in the global carbon budget. Due to the increase in emissions, the stock of greenhouse gases is rising. However, even if we stop emissions from tomorrow, the decline of greenhouse gas stocks will be very slow. This is because carbon dioxide will stay in the atmosphere for a long time after emission, but the response of the climate system is very slow. The inherent inertia of this system means that it takes a long time to show the effect of carbon emission reduction today.
The door to successful emission reduction is closing. Without causing dangerous climate change, the earth's ability to absorb carbon dioxide is limited, and we are approaching this limit. We don't have much time to make sure that the door of opportunity is still open. During this period, we will transition to a low-carbon energy system. This is a highly uncertain field. But what is certain is that if it is still the same as in the past, then the world will not escape the avoidable "double disaster"-the recent retrogression of human development and the danger of ecological disaster to future generations.
Like the disaster on Easter Island, the result can be avoided. At present, the commitment period of Kyoto Protocol will end in 20 12. We can take this opportunity to formulate a multilateral strategy and redefine the management mode of global ecological interdependence. When negotiating the protocol, governments of all countries pointed out that the sustainable carbon budget of 2 1 century should be determined first, and the implementation strategy of carbon budget should be formulated under the condition of "common but different responsibilities" of all countries.
To succeed, the richest country in the world must take the lead. These countries have the deepest carbon footprint, but at the same time, they have the technical and financial ability to significantly reduce emissions as soon as possible. However, an effective multilateral cooperation framework requires the active participation of all major emitters, including developing countries.