National, global and eco-environmental data

Climate change is a reflection of long-term atmospheric state change, and it is a changeable and complicated process. It mainly represents the change of air temperature or humidity in various time lengths, and the alternation of temperature or humidity constitutes different change cycles. These change periods are not strict, and the stages before and after a period are often asymmetric, and the lengths of different periods can also vary greatly. As an important part of natural environment and natural resources, climate is closely related to human society. Extreme abnormal weather phenomena caused by global climate change, such as drought, flood, freezing injury, hail, sandstorm, urban rainstorm waterlogging disaster, lightning disaster, etc. , causing serious natural disasters, seriously affecting the living environment of human beings and the sustainable development of society, and seriously affecting the human ecological environment, human society and human health. Moreover, global warming has a direct impact on the earth's ecosystem and brings harm to human living environment and human health. The level of human health is a comprehensive reflection of a country's social environment, natural environment, material living standard and public welfare level.

A question about global warming

In the past 100 years, the global and China's climate is experiencing significant changes characterized by warming, which has had and will continue to have a significant impact on the ecosystem, social economy and human health of the world and China.

In 20001year, the Intergovernmental Panel on Climate Change (IPCC) established by the World Meteorological Organization and the United Nations Environment Programme published its third assessment report. According to the report, since 1860, the global surface temperature has risen by 0.6℃ 0.2℃ on average, and the last 20 years have been the warmest year in the past 100 years. The 1990s was the hottest year in 1000. Under the background of global warming, the climate in China has also undergone obvious changes in the past century, mainly in the following aspects: the trend of climate change in China in the past century is basically consistent with the general trend of global climate change, and the temperature in China has risen by 0.4℃-0.5℃ in the past century. From the geographical distribution, the most obvious areas of climate warming in China are northwest, north China and northeast China; According to the seasonal distribution, the winter warming in China is the most obvious. According to the latest data from the National Climate Center of China Meteorological Bureau, since 2004, the temperature in China has been generally higher than normal, and it has become a "foregone conclusion" that China will continue to experience the19th warm winter in recent 50 years.

(a) Negative effects of global warming (closely related to human health)

1. The frequency and intensity of high temperature heat wave increase.

According to the statistics of Japanese scientists, in the past 100 years, the annual average temperature of the whole earth increased by 0.7℃, while the average temperature of big cities increased by 2 ~ 3℃. During this period, the temperature in Tokyo actually rose by 7℃. In Japan, the night when the temperature is not lower than 25℃ is called "hot night". Fifty years ago, there were less than five "hot nights" in Tokyo every year; The average value of 196 1 ~ 1970 is14.9; 198 1 ~ 1990, the number of "hot nights" increased to 23.8. During 2000 199 1 ~ 10, the average number of "hot nights" in Osaka reached 38 times.

According to 1940-2002 (see table 1), the extreme maximum temperature in Beijing in the 1940s was relatively high, at 42.6℃. Then there was a downward trend, reaching a minimum of 38.5℃ in the 1980s and rising again in the 1990s, reaching 465,438+0.9℃.

Table 1 Extreme Maximum Temperature in Summer in Beijing

1940~ 1949 1950~ 1959 1960~ 1969 1970~ 1979 1980~ 1989 1990~2000 2000~2002

The extreme maximum value is 42.639.640.140.338.541.941.

high-temperature

China scientists' analysis of the temperature changes in Shanghai and Guangzhou shows that due to climate warming, the number of high temperature days (maximum temperature ≥34℃) in Shanghai will increase from the current 12d/a to the future15.7d/a; The annual high temperature days in Guangzhou will increase from 24.7 days/year now to 36.0 days/year in the future.

2. El Nino phenomenon

According to the IPCC's third climate change assessment report, compared with the past 65,438+000 years, since the 1970s, El Ni? o-Southern Oscillation events have become more frequent, longer lasting and stronger (IPCC's third climate assessment report Working Group I, 2006,5438+0). During two serious El Nino events, 1982 ~ 1983 and 1997 ~ 1998, extreme weather events occurred frequently all over the world, causing great disasters to mankind.

3. Urban heat island is more obvious.

According to relevant data, the maximum heat island intensity (urban-rural temperature difference) in China was observed in 1997, and it was 9℃ in Beijing (6.8℃ higher than that in Shanghai, second only to1/3.3℃ in Vancouver and Berlin, Germany). The heat island effect is the result of many factors, not one aspect. Global warming is one of the reasons for the increase of temperature difference in suburbs.

(b) The impact of global warming on human health

1. Impact of climate warming on disease epidemiology

Human health is closely related to human survival. Climate environment, climate disasters and climate change directly affect human health, and the harm of extreme climate events is even more amazing. Due to global warming, extreme weather events will become more frequent and the harm of climate disasters to human life and health will also increase. Many infectious diseases spread by insects are very sensitive to climate change. For example, global warming will aggravate the spread of malaria and dengue fever. According to statistics from relevant departments, with global warming, malaria and dengue fever alone will harm 40% of the world's population. Most importantly, climate change will inevitably lead to the extinction of some old species, but also produce new species. Changes in species may break the existing patterns of viruses, bacteria, parasites and allergens and produce new varieties. For example, in the spring of 2003, SARS virus infectious disease broke out in Guangdong, Beijing, Shanxi and other places in China, which brought great harm to the health and life of society and people.

Global warming affects the ecosystem, which brings another danger that a new virus may be activated. A research report of the World Health Organization confirms that at least 30 new infectious diseases have appeared in the past 20 years. Most researchers who study emerging viruses believe that the emergence of various new viruses may be the result of human destruction of the environment and climate change disturbing virus nests. These unknown viruses, which originally lived in wild animals and lived in the closed world, will be discovered continuously in the process of human activities.

Global warming and the occurrence of some extreme weather and climate events have brought a strong impact on the ecological balance, especially the microecological balance, significantly changed the survival and variation of infectious disease pathogens, the reproductive distribution and epidemiological characteristics of vector insects, and will play a role in fueling the spread of some infectious diseases. When mosquitoes bite people with infectious virus, the virus will enter healthy people with blood. In a certain temperature range, with the increase of temperature, the reproduction rate and bite rate of mosquitoes are greatly improved, and the reproduction and maturity rate of viruses in their bodies will also increase. For example, at 20℃, Plasmodium falciparum takes 26 days to mature, while at 25℃, it only takes 13 days. The survival cycle of Anopheles mosquitoes carrying this pathogen is only a few weeks, so high temperature will greatly increase the transmission probability of this pathogen. At the same time, due to the high temperature phenomenon, the temperature rises at night and in winter, which greatly prolongs and expands the life cycle and area of mosquitoes and increases the incidence of malignant infectious diseases such as malaria, scarlet fever, jaundice and encephalitis.

Climate warming will also lead to changes in the climate zone, and the boundary of the tropics will be extended to the subtropics, and the original infectious diseases in the tropics will be extended to the temperate zones. For example, the geographical area of tsutsugamushi disease in the south of the Yangtze River in China has been pushed northward since the 1980s, and an epidemic situation has been reported in Shandong Province 1986. 1989 and 1990, the geographical area of tsutsugamushi disease epidemic area in Tianjin pushed northward by four latitudes, and the annual average temperature of tsutsugamushi disease epidemic area in Tianjin increased by 1.3 ~ 1. It is estimated that under the influence of climate warming, tsutsugamushi disease in China may have a nationwide distribution trend. In the summer of 2002, the West Nile virus broke out again in the United States. Experts analyzed that the virus spread so fast, mainly because the weather was dry and hot. West Nile virus was isolated from a woman in West Nile District of Uganda on 1937, and has appeared in temperate regions of Europe and North America in recent years. In addition, due to climate warming, the range of activities of Rattus flavipectus carrying plague is not limited to the south of17 N.

2. High temperature heat wave and mortality

The most direct impact of global warming on human health is the thermal effect caused by extreme high temperature, which will become more frequent and extensive. The increase of intensity and duration of high temperature heat wave leads to the increase of diseases or mortality mainly caused by heart expansion and respiratory system. With the global warming, the number of high-temperature days in summer increases obviously, and the frequency and intensity of high-temperature heat waves also increase accordingly. In particular, the increase of humidity and urban air pollution have further aggravated the impact of extreme high temperature in summer on human health. The most direct impact of heat wave on human health is the increase of morbidity and mortality.

Since the summer of 2003, the heat wave has swept the world, and the temperature in various places has reached a record high of 38~42.6℃. Many elderly people were injured. The heat wave spread to India, Pakistan, Europe and China. In India alone, more than 65,438+0,000 people died from heat waves. With the increase of high temperature and heat wave, the number of patients with heart disease and hypertension is also increasing. In addition, global warming will also lead to an increase in tropospheric ozone concentration and a decrease in stratospheric ozone concentration.

High temperature makes germs, bacteria, parasites and allergens more active, and it will also damage people's spirit, human immunity and disease resistance. It kills more than 654.38+million people worldwide every year. Shanghai 1998 experienced the worst heat wave in recent decades (July 8-20, August 1-3, August 7- 17, August 2 1-23). The total number of deaths during the heat wave period can reach 2-3 times that during the non-heat wave period, and the threat to infants accompanying the heat wave is also great. If babies suffer from certain diseases, such as diarrhea, respiratory infection and mental retardation, they are most vulnerable to high temperature during the heat wave. In addition to the direct impact of heatstroke death, heat waves can also lead to diseases or deaths mainly in the heart and respiratory system. Studies show that with global warming, the number of hot days in summer will increase obviously, and the morbidity and mortality of patients with heart disease and hypertension will increase.

In summer in China, high temperatures above 35℃ often occur everywhere, as well as temperatures above 38℃ and 40℃. From late June to late August, 2003, under the influence of subtropical high, rare high temperature weather occurred in Jiangnan and South China. The maximum daily temperature is higher than or equal to 35℃ for more than 40 days. The daily maximum temperature in Jiangnan and South China is generally 35℃-38℃, which can reach 38℃-40℃ in some areas and 40℃-43℃ in some areas. Physiologists' research shows that once the temperature rises to 38℃, it is difficult for human sweat glands to sweat and maintain normal body temperature. Not only does the lungs breathe out heat, but even the heart beats faster, outputting more blood to the body surface and participating in heat dissipation. For heart patients, this is a life-threatening temperature. When the temperature reaches 39℃, sweat glands fail and tend to fail. At this time, it is easy to have the risk of sudden death caused by heart disease. The temperature has reached 40℃, and the high temperature has reached the center of life, so the brain can't see anything and is dizzy. It can be seen that the human body is very sensitive to the physiological reaction of temperature rise at high temperature. In 2004, influenced by typhoon Dandelion and subtropical high, Guangdong was shrouded in hot weather from the end of June. In July 1 day, the highest temperature in Guangzhou reached 39.7℃, exceeding the historical record of 38.7℃ in Guangzhou. On June 28th, a worker in Taisheng Furniture Factory 8, Dalingshan Town, Dongguan, Guangdong Province fainted due to work fatigue and high temperature in the workshop, and died half an hour after being sent to the hospital. According to the person in charge of "120" emergency center in Guangzhou, since the beginning of summer, the number of people who died of other diseases caused by high temperature in Guangzhou alone has reached 39, which is 66% higher than the average number of ambulances dispatched every day (about 200 times), setting a record for sunrise vehicles since the establishment of the emergency center 10. Taking Beijing as an example, the number of patients who came to the hospital to see high temperature in July increased by 40% compared with that in June. In Shanghai, Gansu and other places, the increase of patients with high temperature leads to high clinical blood consumption and blood shortage. Outdoor workers such as traffic police, bus drivers and construction workers are seriously threatened by the heat wave. High temperature makes people easy to drive fatigue, and major traffic accidents such as flat tire and auto spontaneous combustion occur frequently.

High temperature and summer heat also directly affect people's psychology and emotions, making people tired, irritable and angry, and all kinds of accidents are relatively increasing, and even the crime rate is rising. For example, during the July heat wave in new york 1966, the homicide rate was 138.5% as usual. In July 2003, during the high temperature, traffic accidents in Beijing increased. According to the data of Beijing Emergency Center, the increase of traffic accidents is closely related to the hot weather. When the temperature is high and the air pressure is low, people's brain tissue and myocardium are most sensitive to this, and they are prone to dizziness, irritability and excitement, resulting in some psychological problems.

3. Nino events and diseases

The new experimental results show that Nino phenomenon is closely related to the spread of diseases. The appearance of Nino often leads to abnormal climate in some areas, which in turn leads to diseases. For example, during the Nino incident from 1982 to 1983, the high temperature weather caused by drought in northern Pakistan triggered a malaria epidemic; In Bolivia, Ecuador and Peru in South America, malaria epidemics also occur from time to time due to heavy rains. According to scientists' analysis, in the first year after El Ni? o, malaria cases in Venezuela increased by 35. 1%. During the peak period of El Ni? o activities such as 1997 ~ 1998, 89,000 people in Somalia and Nigeria were infected with Rift Valley fever, and nearly 250 people died. In Pakistan, northwestern India, Sri Lanka, East Africa, Venezuela and Brazil, widespread droughts have led to outbreaks of malaria and scarlet fever. In addition, according to a report of the World Health Organization, during the El Ni? o event of 1982 ~ 1983, about 654.38+million people in the world suffered from depression, the incidence of mental illness increased by 8%, and traffic accidents also increased by more than 5,000 times.

4. Air pollution and health

Air pollution is closely related to meteorological conditions. Under the background of global warming, the local air quality often declines due to the appearance of abnormal weather, such as high temperature in summer, warming in winter and drought. Especially in densely populated cities, due to the existence of urban heat island circulation, air pollutants are difficult to spread and cause serious pollution.

After pollutants from big cities enter human body, they will cause uncomfortable reactions of human sensory and physiological functions, subclinical and pathological changes, clinical signs or potential genetic effects, acute and chronic poisoning or death. The smog events in Maas Valley, Belgium (1930), Donora, USA (1948) and London, England (1952) are typical examples of the impact of air pollution.

2. Natural disasters caused by climate change and human health problems

Since 1960, the world population has doubled, but the disaster losses have increased 30 times, from $3 billion in 1960 to $0/000 billion. Climate disasters are part of this growing trend. For example, Typhoon Andrew 1992 caused a loss of $24 billion in the southern suburbs of Miami. The potential impact of natural disasters may increase due to climate warming. Assuming that the temperature changes or the rainfall distribution does not change, global warming will lead to an increase in the incidence of floods and high temperatures. Since floods are usually related to the Southern Oscillation, the possibility of drought aggravation cannot be ruled out. These climate disasters will cause more forest fires and mudslides. The impact of these disasters on health and society includes death, physical injury, mental trauma, social chaos and so on.

(1) flood

Historically, floods have caused the greatest death losses in various natural disasters. So far, the worst-hit area is the Yellow River in China. 1332, 7 million people drowned,1000000 people died of subsequent famine and disease. 1887 flood washed away the 22m-high dike and drowned 1 10,000 people. The recent flood occurred in 1930, and1000000 people drowned in China, and another110000000 people may die from the subsequent famine. Floods in the Mississippi River in the United States continue to destroy businesses. The recent floods occurred in 1973 ~ 1974 and 1993. The storms in the Middle Ages produced extreme flood events in rivers in northern Europe, and the death toll of several events exceeded 65,438+10,000. 1995 The winter flood in northern Europe was the worst in the last 200 years. In Australia, floods became more common in the second half of the 20th century. During the La Nina events from 1988 to 1990, the land in eastern Australia 1× suffered severe floods. Besides, the occurrence of floods will not only increase the risk of drowning, diarrhea and respiratory diseases, but also increase the risk of hunger and malnutrition in developing countries.

(2) Drought

Among all natural disasters related to climate, drought is the most serious and extensive natural disaster. The droughts in Indian subcontinent 1769, 1790, 1866, 1876 ~ 1977 and 1943 claimed millions of lives. During the period of 1878,1000 ~130,000 people in China died of drought-related famine. Many drought events are related to ENSO events. If famine occurs during drought, malnutrition and disease will cause permanent mental and physical harm. Not all famines are caused by drought, and not all droughts cause famines. Drought is everywhere, affecting both developed and developing countries. Although drought will lead to long-term illness, it has little effect on population growth. Because of the exact periodicity of droughts in most parts of the world, it is doubtful whether climate warming can reduce the intensity and frequency of droughts. For example, although the humidity in eastern Australia has increased by 30% since 1950, the intensity and frequency of drought have not decreased. In fact, the most serious droughts occurred in 1982 ~ 1983 and 199 1 ~ 1995.

(3) Forest fire

Throughout history, we can see that there have been many forest fires in history. In North America, at least 65,438+03 fires destroyed 40,000 hectares of forest. 187 1 Forest fires in Wisconsin and Michigan destroyed 1.7 million hectares of forest, killing 2,200 people. There are similar regional fires in 1894 Wisconsin, 19 10 Idaho and northwest Montana. Michigan Fire 188 1 Hundreds of people were killed; 1894 Fire in hinkley, Minnesota, 4 18 people were killed. 19 18 croquet fire in Minnesota, killing 55 1 person. The fire was so common that residents took a cold attitude when they heard it, as if they had lost their property.

The decisive factors of forest fire are the amount of fire source and combustible materials and the climatic conditions conducive to combustion and spread. The latter two factors are the impact of global climate change. The rainfall in the first few months of the fire danger period is an important parameter. Appropriate rainfall in spring and early summer will reduce forest fires, but it will provide sufficient undergrowth vegetation for future high fire risks. Severe early drought will completely dry this vegetation and increase the amount of combustible materials. Recently, floods and extreme droughts are fires in some countries, such as Australia, and every situation is conducive to fires. Relatively low humidity and strong wind also play a key role in determining the possibility and intensity of forest fires. Any large-scale fire depends not only on climatic conditions, but also on diseases (or insect infectious diseases), storms, previous fires or dry debris and residues produced by land development. Under the "fertilization" effect of high concentration of carbon dioxide, high fuel quantity is related to warm and humid climate conditions.

3. Countermeasures to mitigate the impact of climate change on human health:

The history of mankind is a survival history that constantly adapts to the climate and environment. The challenges brought by climate change to mankind are inevitable. It is our common responsibility to protect the earth's climate and prevent its deterioration for the sustainable development of social economy and the living environment of human beings. It is urgent to slow down global warming, vigorously study the relationship between climate change and human health, and establish and improve the disease monitoring and early warning system that affects public health.

1. On the basis of the existing meteorological index forecasting and services for human health and life, common diseases and frequently-occurring diseases, the research and service field will be extended to the field of infectious diseases, and short-,medium-and long-term infectious disease forecasting and early warning services will be carried out to form a series of products.

2 to carry out climate risk assessment and climate zoning research on major epidemics and infectious diseases. The main research contents include: studying the relationship between the breeding, transmission and outbreak of diseases and climate, and determining favorable and unfavorable weather and climate conditions; Study on climate assessment model of diseases: applying geographic information system technology, integrating environmental databases such as epidemic situation and climate, carrying out disease climate zoning, and determining the focus of infectious disease prevention and control in each season and region; Establish a real-time operational system for climate monitoring and disease early warning; Establish a production and distribution system of information products serving the public, and provide rich, accurate, timely and authoritative service products such as disease monitoring, evaluation, prediction, early warning and disease prevention for the society.

3, to carry out research on microclimate and disease breeding and spreading indoors or in transportation. Strengthen the development and utilization of climate resources change, reduce the loss of natural disasters, and improve the ability of climate change research and prediction. Heat waves can be monitored and predicted. At present, many cities at home and abroad have issued early warning of high temperature or heat wave. According to the regulations of China Meteorological Bureau, the daily maximum temperature is above 35℃, and a high temperature forecast is issued. From June 28th to July 3rd, 2004, Guangdong Meteorological Observatory issued red warning signal for 23 times, which is unprecedented in the meteorological history of Guangdong Province. In this way, when the heat wave comes, people can effectively take various adaptation measures, greatly reduce the impact of the heat wave on human health, and gradually improve the heat wave early warning system.

4. Uncertainty of research on the impact of climate change on human health

There is relatively little research on the impact of climate change on human health, and there are still many uncertainties in the preliminary conclusions, which poses a severe challenge to scientists.

1. The key is to extract the impact of climate from many factors that affect health.

In epidemiological research, because climate change is usually accompanied by other environmental changes, its impact on human health is not unique, but also affected by heredity, self-quality, diet, living habits, environment and other factors. Therefore, the key technology to study the impact of climate change on health is to separate the impact of automobile climate from many health factors.

2. The sensitivity of health to climate change is very complicated.

In order to cope with the current global climate change and future changes, some changes in human health may be happening or about to happen. In addition, in the next few decades, with climate change, society, economy, population, science and technology, and medical care will all change, and these changes are difficult to accurately predict in the next few decades. Therefore, the sensitivity of human health to climate change is quite complex, which brings great difficulties to study the impact of climate change on human health.