The controversy between the IPCC and Non-governmental IPCC(NIPCC) on the attribution of global warming are reviewed.IPCC holds that today's global warming is mainly due to anthropogenic activities rather than natu...The controversy between the IPCC and Non-governmental IPCC(NIPCC) on the attribution of global warming are reviewed.IPCC holds that today's global warming is mainly due to anthropogenic activities rather than natural variability,which is emphasized by NIPCC.The surface temperature observations since the mid-20th century support the hypothesis of anthropogenic impact,but for the last one hundred years or so,natural forcings such as solar activity, volcanic eruptions and thermohaline circulation variations also have had great influences on the Earth's climate,especially on inter-decadal timescales.In addition,evidence suggests that the Medieval Warm Period(MWP) and Little Ice Age (LIA) are closely associated with the solar activity over the past 1 thousand years.Over the past 10 thousand years, the North Atlantic cold events and solar activity are closely correlated.Nevertheless,the physical mechanisms of the solar-climate variability and interrelation are not well understood,yet.Notably,a prevailing view recently indicates that galactic cosmic rays may result in climatic cooling through modulating global low cloud cover.However,its process and mechanism need to be further investigated.展开更多
Global warming is unequivocal, as is manifested in three internationally known global temperature records with the global average temperature rising at a rate of 0.70-0.75℃ per 100 years during 1910-2009 [Wen et al.,...Global warming is unequivocal, as is manifested in three internationally known global temperature records with the global average temperature rising at a rate of 0.70-0.75℃ per 100 years during 1910-2009 [Wen et al., 2011]. In other words, the earth has warmed more than 0.8℃ since the Industrial Revolution. If it is true that 2℃ above pre-industrial level is a threshold of climate ＂safety＂, we will have to confront a serious situation where less than 1.2℃ warmins is oermissible in the future [Liu et al.. 2011].展开更多
According to the IPCC Fourth Assessment Report （AR4） [IPCC, 2007], the global mean surface temperature in 2100 is projected to be 1.1-6.4℃ higher than the 1980 1999 mean state, with the best estimation of increase ...According to the IPCC Fourth Assessment Report （AR4） [IPCC, 2007], the global mean surface temperature in 2100 is projected to be 1.1-6.4℃ higher than the 1980 1999 mean state, with the best estimation of increase at 1.8-4.0℃. It should be noted that this is the projected range of increase rather than the so-called uncertainties in global warming projection. Specifically, 1.1℃ and 1.8℃ are the lower limit and the best estimation for the B1 emissions scenario （the low emissions scenario）, respectively; while 4.0℃ and 6.4℃ are the corresponding upper limit and the best estimation for the A1F1 emissions scenario （the high emissions scenario）. Therefore,展开更多
Equilibrium climate sensitivity （ECS） is usually defined as the global mean equilibrium temperature response to a doubling CO2 concentration of its preindustrial level in the atmosphere[Hegerl et al., 2007;Meehl et ...Equilibrium climate sensitivity （ECS） is usually defined as the global mean equilibrium temperature response to a doubling CO2 concentration of its preindustrial level in the atmosphere[Hegerl et al., 2007;Meehl et al., 2007].展开更多
The planetary wave response to global warm ing with single forcing of greenhouse gases （GHGs） is investigated in this study by using a total of 11 model results that anticipated CMIP3 4XCO2 experiments. It is shown ...The planetary wave response to global warm ing with single forcing of greenhouse gases （GHGs） is investigated in this study by using a total of 11 model results that anticipated CMIP3 4XCO2 experiments. It is shown that the amplitudes of the planetary wave fluxes over Siberia, the Eastern North Pacific, and the North Atlantic decrease by approximately -10% to -30% in the warming context. In particular, the vertical wave flux over the Eastern North Pacific significantly decreases by -28.6%. The weakening of the planetary waves is partly associated with the decreased land-sea thermal contrast, which may be caused by the radiation effect of CO2 and the different surface heat capacities of land and sea. The present work provides a clear understanding of the re sponses of planetary waves to GHGs forcing.展开更多
基金supported by National Basic Research Program of China(No.2010CB950104)
文摘The controversy between the IPCC and Non-governmental IPCC(NIPCC) on the attribution of global warming are reviewed.IPCC holds that today's global warming is mainly due to anthropogenic activities rather than natural variability,which is emphasized by NIPCC.The surface temperature observations since the mid-20th century support the hypothesis of anthropogenic impact,but for the last one hundred years or so,natural forcings such as solar activity, volcanic eruptions and thermohaline circulation variations also have had great influences on the Earth's climate,especially on inter-decadal timescales.In addition,evidence suggests that the Medieval Warm Period(MWP) and Little Ice Age (LIA) are closely associated with the solar activity over the past 1 thousand years.Over the past 10 thousand years, the North Atlantic cold events and solar activity are closely correlated.Nevertheless,the physical mechanisms of the solar-climate variability and interrelation are not well understood,yet.Notably,a prevailing view recently indicates that galactic cosmic rays may result in climatic cooling through modulating global low cloud cover.However,its process and mechanism need to be further investigated.
基金funded by the National Basic Research Program of China(No.2010CB950104)the Strategic Priority Research Program of the Chinese Academy of Sciences(No. 9-XDA05090104)
文摘Global warming is unequivocal, as is manifested in three internationally known global temperature records with the global average temperature rising at a rate of 0.70-0.75℃ per 100 years during 1910-2009 [Wen et al., 2011]. In other words, the earth has warmed more than 0.8℃ since the Industrial Revolution. If it is true that 2℃ above pre-industrial level is a threshold of climate ＂safety＂, we will have to confront a serious situation where less than 1.2℃ warmins is oermissible in the future [Liu et al.. 2011].
基金supported by the National Natural Science Foundation of China(No.41005035)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA05080801 and XDA05090104)
文摘According to the IPCC Fourth Assessment Report （AR4） [IPCC, 2007], the global mean surface temperature in 2100 is projected to be 1.1-6.4℃ higher than the 1980 1999 mean state, with the best estimation of increase at 1.8-4.0℃. It should be noted that this is the projected range of increase rather than the so-called uncertainties in global warming projection. Specifically, 1.1℃ and 1.8℃ are the lower limit and the best estimation for the B1 emissions scenario （the low emissions scenario）, respectively; while 4.0℃ and 6.4℃ are the corresponding upper limit and the best estimation for the A1F1 emissions scenario （the high emissions scenario）. Therefore,
基金supported by the National Natural Science Foundation of China (No. 41005035)the Strategic Priority Research Program of Chinese Academy of Sciences (No. XDA05080801 and XDA05090104)
文摘Equilibrium climate sensitivity （ECS） is usually defined as the global mean equilibrium temperature response to a doubling CO2 concentration of its preindustrial level in the atmosphere[Hegerl et al., 2007;Meehl et al., 2007].
基金supported by the National Natural Science Foundation of China (Grant Nos. 41130962 and 41005035)the National Basic Research Project Program of China (973 Program, Grant No.2010CB428606)
文摘The planetary wave response to global warm ing with single forcing of greenhouse gases （GHGs） is investigated in this study by using a total of 11 model results that anticipated CMIP3 4XCO2 experiments. It is shown that the amplitudes of the planetary wave fluxes over Siberia, the Eastern North Pacific, and the North Atlantic decrease by approximately -10% to -30% in the warming context. In particular, the vertical wave flux over the Eastern North Pacific significantly decreases by -28.6%. The weakening of the planetary waves is partly associated with the decreased land-sea thermal contrast, which may be caused by the radiation effect of CO2 and the different surface heat capacities of land and sea. The present work provides a clear understanding of the re sponses of planetary waves to GHGs forcing.
