Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experime...Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experiments using regional climate model RegCM4. In the first experiment used to study the climatic responses to human carbon emissions, the model were configured over entire China because the impacts of carbon emissions can be detected across the whole country. Results from the first experiment revealed that near-surface air temperature may significantly increase from 2007 to 2059 at a rate exceeding 0.1 ~C per decade in most areas across the country; southwestern and southeastern China also showed increasing trends in summer precipitation, with rates exceeding 10 mm per decade over the same period. In summer, only northern China showed an increasing trend of evapotranspiration, with increase rates ranging from 1 to 5 mm per decade; in winter, increase rates ranging from 1 to 5 mm per decade were observed in most regions. These effects are believed to be caused by global warming from human carbon emissions. In the second experiment used to study the effects of human water use, the model were configured over a limited region-- Haihe River Basin in the northern China, because compared with the human carbon emissions, the effects of human water use are much more local and regional, and the Haihe River Basin is the most typical region in China that suffers from both intensive human groundwater exploitation and surface water diversion. We incorporated a scheme of human water regulation into RegCM4 and conducted the second experiment. Model outputs showed that the groundwater table severely declined by -10 m in 1971-2000 through human groundwater over- exploitation in the basin; in fact, current conditions are so extreme that even reducing the pumping rate by half cannot eliminate the ground- water depletion cones observed in the area. Other hydrological and climatic elements, such as soil moisture, runoff generation, air humidity, precipitation, wind field, and soil and air temperature, were also significantly affected by anthropogenic water withdrawal and consumption, although these effects could be mitigated by reducing the amount of water drawn for extraction and application.展开更多
According to the authoritative data involving social economic indicators and greenhouse gas （GHG） emission from the international universal database, the levels and processes of economic development and GHG emission...According to the authoritative data involving social economic indicators and greenhouse gas （GHG） emission from the international universal database, the levels and processes of economic development and GHG emission in major economic groups, nations and regions of the world are simultaneously analyzed. Obtaining Gross Domestic Product （GDP） and emission per capita from various countries and regions in the past 40 years as the standard, countries and regions in the world are divided into six groups： countries with low emission per capita and low economic level （IA）, countries with low emission per capita and medium economic level （IIA）, countries with low emission per capita and high economic level （IIIA）, countries with high emission per capita and medium economic level （liB）, countries with high emission per capita and high economic level （IIIB）, countries with high emission per capita and low economic level （IB）. Countries belong to IB are quite rare in the study period, while the first five groups correspond to the poor regions, main developing countries, economically transitional countries with rapid economic development, rich islands and developed North America and Europe respectively. Data analysis shows that there is a close relationship between emission and economic development of different countries and regions. The composition relationship between economic development of different countries and regions is relatively stable over a long period of time. From 1970 to 2005, rising trends existed in the economic development of most countries and regions. However, the emission had a significant increase in a small part of countries and regions. In other words, for those with high emission, the emission level is always high. But for those with low GHG emission, the emission does not increase too much. The main processes of the change of countries pattern from IA to IIA and from II B to IIIB, occurring in the 1970s and from the late 1970s to the 1980s respectively. That result has .a significant enlightening effect in understanding the relationship between emission and eco- nomic development and its historical process of various countries and in choosing the position of our country in the future climate diplomatic negotiations.展开更多
In recent decades, there have been a number of debates on climate warming and its driving forces. Based on an extensive literature review, we suggest that （1） climate warming occurs with great uncertainty in the mag...In recent decades, there have been a number of debates on climate warming and its driving forces. Based on an extensive literature review, we suggest that （1） climate warming occurs with great uncertainty in the magnitude of the temperature increase; （2） both human activities and natural forces contribute to climate change, but their relative contributions are difficult to quan- tify; and （3） the dominant role of the increase in the atmospheric concentration of greenhouse gases （including CO2） in the global warming claimed by the Intergovernrnental Panel on Climate Change （IPCC） is questioned by the scientific communities because of large uncertainties in the mechanisms of natural factors and anthropogenic activities and in the sources of the increased atmospheric CO2 concentration. More efforts should be made in order to clarify these uncertainties.展开更多
Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction ...Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction between the coupled earth system models and the IAMs. This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University （BNU-ESM）. With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.展开更多
This article analyzed climate change risks from the perspective of con- temporary environmental risks and how they have been internalized by policy. In order to do so, the main characteristics of this type of risk wer...This article analyzed climate change risks from the perspective of con- temporary environmental risks and how they have been internalized by policy. In order to do so, the main characteristics of this type of risk were analyzed based on the contributions from social theory authors on contemporary environmental risks. Next, the implications of these characteristics for the production of policy responses to climate change risks were discussed. The two main types of policy responses to climate change in the literature were presented： mitigation and adaptation. Finally, their interaction, differences and possibilities for synergy were analyzed. Under- standing climate change as a contemporary environmental risk, the way it was presented in this article, implies a radical change in the development bases of society, since greenhouse gases emissions from human activities contribute to the aggravation of global warming. Climate change challenges the traditional ways of governing in many ways, since climate change policy should involve the ques- tioning of the current processes of development. Profound changes in ways of thinking and established political action are needed.展开更多
文摘Carbon emissions and water use are two major kinds of human activities. To reveal whether these two activities can modify the hydrological cycle and climate system in China, we conducted two sets of numerical experiments using regional climate model RegCM4. In the first experiment used to study the climatic responses to human carbon emissions, the model were configured over entire China because the impacts of carbon emissions can be detected across the whole country. Results from the first experiment revealed that near-surface air temperature may significantly increase from 2007 to 2059 at a rate exceeding 0.1 ~C per decade in most areas across the country; southwestern and southeastern China also showed increasing trends in summer precipitation, with rates exceeding 10 mm per decade over the same period. In summer, only northern China showed an increasing trend of evapotranspiration, with increase rates ranging from 1 to 5 mm per decade; in winter, increase rates ranging from 1 to 5 mm per decade were observed in most regions. These effects are believed to be caused by global warming from human carbon emissions. In the second experiment used to study the effects of human water use, the model were configured over a limited region-- Haihe River Basin in the northern China, because compared with the human carbon emissions, the effects of human water use are much more local and regional, and the Haihe River Basin is the most typical region in China that suffers from both intensive human groundwater exploitation and surface water diversion. We incorporated a scheme of human water regulation into RegCM4 and conducted the second experiment. Model outputs showed that the groundwater table severely declined by -10 m in 1971-2000 through human groundwater over- exploitation in the basin; in fact, current conditions are so extreme that even reducing the pumping rate by half cannot eliminate the ground- water depletion cones observed in the area. Other hydrological and climatic elements, such as soil moisture, runoff generation, air humidity, precipitation, wind field, and soil and air temperature, were also significantly affected by anthropogenic water withdrawal and consumption, although these effects could be mitigated by reducing the amount of water drawn for extraction and application.
文摘According to the authoritative data involving social economic indicators and greenhouse gas （GHG） emission from the international universal database, the levels and processes of economic development and GHG emission in major economic groups, nations and regions of the world are simultaneously analyzed. Obtaining Gross Domestic Product （GDP） and emission per capita from various countries and regions in the past 40 years as the standard, countries and regions in the world are divided into six groups： countries with low emission per capita and low economic level （IA）, countries with low emission per capita and medium economic level （IIA）, countries with low emission per capita and high economic level （IIIA）, countries with high emission per capita and medium economic level （liB）, countries with high emission per capita and high economic level （IIIB）, countries with high emission per capita and low economic level （IB）. Countries belong to IB are quite rare in the study period, while the first five groups correspond to the poor regions, main developing countries, economically transitional countries with rapid economic development, rich islands and developed North America and Europe respectively. Data analysis shows that there is a close relationship between emission and economic development of different countries and regions. The composition relationship between economic development of different countries and regions is relatively stable over a long period of time. From 1970 to 2005, rising trends existed in the economic development of most countries and regions. However, the emission had a significant increase in a small part of countries and regions. In other words, for those with high emission, the emission level is always high. But for those with low GHG emission, the emission does not increase too much. The main processes of the change of countries pattern from IA to IIA and from II B to IIIB, occurring in the 1970s and from the late 1970s to the 1980s respectively. That result has .a significant enlightening effect in understanding the relationship between emission and eco- nomic development and its historical process of various countries and in choosing the position of our country in the future climate diplomatic negotiations.
基金supported by the Academic Division of the Chinese Academy of Sciencesthe National Natural Science Foundation of China (Grant No. 31021001)the National Basic Research Program of China (Grant No. 2010CB950600)
文摘In recent decades, there have been a number of debates on climate warming and its driving forces. Based on an extensive literature review, we suggest that （1） climate warming occurs with great uncertainty in the magnitude of the temperature increase; （2） both human activities and natural forces contribute to climate change, but their relative contributions are difficult to quan- tify; and （3） the dominant role of the increase in the atmospheric concentration of greenhouse gases （including CO2） in the global warming claimed by the Intergovernrnental Panel on Climate Change （IPCC） is questioned by the scientific communities because of large uncertainties in the mechanisms of natural factors and anthropogenic activities and in the sources of the increased atmospheric CO2 concentration. More efforts should be made in order to clarify these uncertainties.
基金supported by the National Natural Science Foundation of China (41605036 and 41305053)the National Key Research and Development Program of China (2016YFA0602703)+1 种基金the National-Level Major Cultivation Project of Guangdong Province (2014GKXM058)the Open Project of the State Key Laboratory of Cryospheric Science (SKLCS-OP-2016-09)
文摘Future climate change is usually projected by coupled earth system models under specific emission sce- narios designed by integrated assessment models （IAMs）, and this offline approach means there is no interaction between the coupled earth system models and the IAMs. This paper introduces a new method to design possible future emission scenarios and corresponding climate change, in which a simple economic and climate damage component is added to the coupled earth system model of Beijing Normal University （BNU-ESM）. With the growth of population and technological expertise and the declining emission-to-output ratio described in the Dynamic Inte- grated Climate-Economy model, the projected carbon emission is 13.7 Gt C, resulting in a 2.4℃ warming by the end of the twenty-first century （2080-2099） compared with 1980-1999. This paper also suggests the importance of the land and ocean carbon cycle in determining the CO2 con- centration in the atmosphere. It is hoped that in the near future the next generation of coupled earth system models that include both the natural system and the social dimension will be developed.
文摘This article analyzed climate change risks from the perspective of con- temporary environmental risks and how they have been internalized by policy. In order to do so, the main characteristics of this type of risk were analyzed based on the contributions from social theory authors on contemporary environmental risks. Next, the implications of these characteristics for the production of policy responses to climate change risks were discussed. The two main types of policy responses to climate change in the literature were presented： mitigation and adaptation. Finally, their interaction, differences and possibilities for synergy were analyzed. Under- standing climate change as a contemporary environmental risk, the way it was presented in this article, implies a radical change in the development bases of society, since greenhouse gases emissions from human activities contribute to the aggravation of global warming. Climate change challenges the traditional ways of governing in many ways, since climate change policy should involve the ques- tioning of the current processes of development. Profound changes in ways of thinking and established political action are needed.
