The Paris Agreement introduced a 1.5 ℃ target to control the rise in global temperature, but clear arrangements for feasible implementation pathways were not made. Achieving the 1.5 ℃ target imposes high requirement...The Paris Agreement introduced a 1.5 ℃ target to control the rise in global temperature, but clear arrangements for feasible implementation pathways were not made. Achieving the 1.5 ℃ target imposes high requirements on global emission reduction. Nationally Determined Con- tributions of all Parties are far from the 1.5 ℃ target, and conventional emission reduction technologies and policies will also have difficulty in fulfilling this task. In this context, geoengineering is gaining interest in the international arena. The Paris Agreement includes afforestation, carbon capture, utilization and storage, and negative emission technologies such as bio-energy with carbon capture and store. All of these techniques are CO2 removal technologies that belong to geoengineering. Solar radiation management, which is highly controversial, has also attracted increased attention in recent years. Although the outline of the IPCC Special Report on 1.5 ℃ does not include a specific section on geoengineering issues yet, geoengineering is an unconventional technical option that cannot be avoided in research and discussions on impact assessment, technical options, ethics, and international governance under the 1.5 ℃ target. On the basis of analyzing and discussing abovementioned issues, this paper proposes several policy suggestions for China to strengthen research on and response to geoengineering.展开更多
Litter decomposition impacts carbon(C)and nutrient cycling.Nitrogen(N)and phosphorus(P)addition as well as litter age impact litter decomposition.Effects of nutrient addition and litter age on litter decomposition may...Litter decomposition impacts carbon(C)and nutrient cycling.Nitrogen(N)and phosphorus(P)addition as well as litter age impact litter decomposition.Effects of nutrient addition and litter age on litter decomposition may impact emissions of soil nitrous oxide(N_(2)O),which is an important greenhouse gas.However,no study has examined the effects of interactions between litter age and nutrient addition on soil N_(2)O emissions,and explored the underlining mechanisms simultaneously,thus limiting our evaluation of litter decomposition effects on N_(2)O emissions.Litter with different age was collected from Cunninghamia lanceolata plantations experienced N and P addition treatments to examine the effects of nutrient addition and litter age on N_(2)O emissions by incubation study.Litter age generally increased N_(2)O emissions via a decrease in litter C:N ratio.While P addition decreased N_(2)O emissions,N addition increased them mainly by positive effects on soil enzymes as indicated by microbial functional genes associated with N_(2)O production and negative effects on litter C:N ratio.Litter age and nutrient addition interacted to impact soil N_(2)O emissions.In future forest management,both nutrient addition and litter age should be considered in evaluation of management effects on N_(2)O emissions,especially thinning or selectively cutting involving litter input with different age.展开更多
文摘The Paris Agreement introduced a 1.5 ℃ target to control the rise in global temperature, but clear arrangements for feasible implementation pathways were not made. Achieving the 1.5 ℃ target imposes high requirements on global emission reduction. Nationally Determined Con- tributions of all Parties are far from the 1.5 ℃ target, and conventional emission reduction technologies and policies will also have difficulty in fulfilling this task. In this context, geoengineering is gaining interest in the international arena. The Paris Agreement includes afforestation, carbon capture, utilization and storage, and negative emission technologies such as bio-energy with carbon capture and store. All of these techniques are CO2 removal technologies that belong to geoengineering. Solar radiation management, which is highly controversial, has also attracted increased attention in recent years. Although the outline of the IPCC Special Report on 1.5 ℃ does not include a specific section on geoengineering issues yet, geoengineering is an unconventional technical option that cannot be avoided in research and discussions on impact assessment, technical options, ethics, and international governance under the 1.5 ℃ target. On the basis of analyzing and discussing abovementioned issues, this paper proposes several policy suggestions for China to strengthen research on and response to geoengineering.
基金funded by the National Natural ScienceFoundationof China(31770749,31760200)Jiangxi Province Science Foundation for Youths(20181BAB214014)Project of Jiangxi Education Department(GJJ190173).
文摘Litter decomposition impacts carbon(C)and nutrient cycling.Nitrogen(N)and phosphorus(P)addition as well as litter age impact litter decomposition.Effects of nutrient addition and litter age on litter decomposition may impact emissions of soil nitrous oxide(N_(2)O),which is an important greenhouse gas.However,no study has examined the effects of interactions between litter age and nutrient addition on soil N_(2)O emissions,and explored the underlining mechanisms simultaneously,thus limiting our evaluation of litter decomposition effects on N_(2)O emissions.Litter with different age was collected from Cunninghamia lanceolata plantations experienced N and P addition treatments to examine the effects of nutrient addition and litter age on N_(2)O emissions by incubation study.Litter age generally increased N_(2)O emissions via a decrease in litter C:N ratio.While P addition decreased N_(2)O emissions,N addition increased them mainly by positive effects on soil enzymes as indicated by microbial functional genes associated with N_(2)O production and negative effects on litter C:N ratio.Litter age and nutrient addition interacted to impact soil N_(2)O emissions.In future forest management,both nutrient addition and litter age should be considered in evaluation of management effects on N_(2)O emissions,especially thinning or selectively cutting involving litter input with different age.
