Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 s...Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 since the beginning of the 20th century, identifying a strengthening linkage, such that in recent decades the rate of sea-ice decrease mirrors the increase in CO 2 , with r ～ -0.95 over the last four decades, thereby indicating that 90% (r 2 ～ 0.90) of the decreasing sea-ice extent is empirically "accounted for" by the increasing CO 2 in the atmosphere. The author presents an empirical relation between annual sea-ice extent and global atmospheric CO 2 concentrations, in which sea-ice reductions are linearly, inversely proportional to the magnitude of increase of CO 2 over the last few decades. This approximates sea-ice changes during the most recent four decades, with a proportionality constant of 0.030 million km 2 per ppmv CO 2 . When applied to future emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), this relationship results in substantially faster ice decreases up to 2050 than predicted by IPCC models. However, departures from this projection may arise from non-linear feedback effects and/or temporary natural variations on interannual timescales, such as the record minimum of sea-ice extent observed in September 2007.展开更多
The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated developm...The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated development of urban and rural areas,but also plays an essential role in poverty alleviation development and the relocation of poverty alleviation. It provides a strong guarantee for winning the project of poverty alleviation. Taking the project of linkage of urban construction land increase with rural construction land decrease in Binchuan County in Yunnan Province,combined with the current situation of poverty alleviation and relocation in Binchuan County,the implementation of related policies of linkage of urban construction land increase with rural construction land decrease,and path of relocation poverty alleviation,this paper introduced problems in the implementation of policies of linkage of urban construction land increase with rural construction land decrease in Binchuan County,and came up with recommendations for the project of poverty alleviation through linkage of urban construction land increase with rural construction land decrease.展开更多
With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, name...With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land.展开更多
基金supported by the Mohn-Sverdrup Center for Global Ocean StudiesOperational Oceanography at the Nansen Center and the Research Council of Norway+1 种基金is a contribution to the International Polar Year―Climate of the Arcticits Role for Europe (IPY-CARE) project, headed by the author
文摘Arctic sea ice is a keystone indicator of greenhouse-gas induced global climate change, which is expected to be amplified in the Arctic. Here we directly compare observed variations in arctic sea-ice extent and CO 2 since the beginning of the 20th century, identifying a strengthening linkage, such that in recent decades the rate of sea-ice decrease mirrors the increase in CO 2 , with r ～ -0.95 over the last four decades, thereby indicating that 90% (r 2 ～ 0.90) of the decreasing sea-ice extent is empirically "accounted for" by the increasing CO 2 in the atmosphere. The author presents an empirical relation between annual sea-ice extent and global atmospheric CO 2 concentrations, in which sea-ice reductions are linearly, inversely proportional to the magnitude of increase of CO 2 over the last few decades. This approximates sea-ice changes during the most recent four decades, with a proportionality constant of 0.030 million km 2 per ppmv CO 2 . When applied to future emission scenarios of the Intergovernmental Panel on Climate Change (IPCC), this relationship results in substantially faster ice decreases up to 2050 than predicted by IPCC models. However, departures from this projection may arise from non-linear feedback effects and/or temporary natural variations on interannual timescales, such as the record minimum of sea-ice extent observed in September 2007.
基金Supported by the Project of Poverty Alleviation Office of People’s Government of Dali Bai Autonomous Prefecture
文摘The policy of linkage of urban construction land increase with rural construction land decrease is an important task for poverty alleviation. It not only promotes the intensive use of land and the coordinated development of urban and rural areas,but also plays an essential role in poverty alleviation development and the relocation of poverty alleviation. It provides a strong guarantee for winning the project of poverty alleviation. Taking the project of linkage of urban construction land increase with rural construction land decrease in Binchuan County in Yunnan Province,combined with the current situation of poverty alleviation and relocation in Binchuan County,the implementation of related policies of linkage of urban construction land increase with rural construction land decrease,and path of relocation poverty alleviation,this paper introduced problems in the implementation of policies of linkage of urban construction land increase with rural construction land decrease in Binchuan County,and came up with recommendations for the project of poverty alleviation through linkage of urban construction land increase with rural construction land decrease.
文摘With the methods of qualitative analysis, induction and deduction, modes of key links in increase and decrease connection of urban and rural construction land are proposed in view of the involved three key links, namely reclamation of rural construction land, fund raising and management of connection turnover index, based on the comprehensive analysis of political connotation in increase and decrease of urban and rural construction land. The modes include "village relocation and combination", "hollow village" reconstruction, high-rise stereo, village relocation in the mountain and related capital raising and turnover index management and the applicable regions of various modes are analyzed and studied. The research result provides reference for the reasonable operation of increase and decrease link of urban and rural construction land.
