The greenhouse gas budget on the Tibetan Plateau remains unknown and the potential for methane(CH_(4))and nitrous oxide(N_(2)O)emissions from an intensifying livestock system and expanding surface water in offsetting ...The greenhouse gas budget on the Tibetan Plateau remains unknown and the potential for methane(CH_(4))and nitrous oxide(N_(2)O)emissions from an intensifying livestock system and expanding surface water in offsetting terrestrial carbon dioxide(CO_(2))sinks are both of great concerns and uncertainties,which compromise an accurate assessment of Tibetan Plateau contribution to China’s ambitious climate goals by 2060s.Here we integrated greenhouse gas flux measurements at∼500 sites in empirical modeling approaches,emissions from the livestock sector with process-based biogeochemistry modeling to estimate CH_(4)and N_(2)O fluxes across terrestrial ecosystems and inland waters in 2000s and 2010s.We found that emissions from livestock and inland waters,predominantly contributed by CH_(4),compensated∼21%and∼13%of carbon sinks provided by forests and grasslands after adjusting carbon burial in sediments and riverine carbon export,respectively.The Tibetan Plateau then acted as an appreciable greenhouse gas sink that almost compensated for its contemporary anthropogenic emissions,making it nearly climate-neutral.The enhancement of terrestrial CO_(2)sinks in the 2060s under medium warming scenario would be counterbalanced by livestock CH_(4)emissions when the current overgrazing status continues.By transitioning to a livestock-forage balance and implementing mitigation initiatives to reduce livestock emission intensity,the greenhouse gas sink is projected to increase by more than 1.5 times.We suggested that a transition towards sustainable pastoralism illuminates the path to minimizing ecosystem greenhouse gas emissions and amplifying the role of the Tibetan Plateau in fulfilling China’s climate ambition.展开更多
The contemporary carbon balance over the Tibetan Plateau is highly uncertain with a ten-fold difference between various estimates.In a warming world,the potential exists for a large carbon release from its permafrost ...The contemporary carbon balance over the Tibetan Plateau is highly uncertain with a ten-fold difference between various estimates.In a warming world,the potential exists for a large carbon release from its permafrost which could compromise China’s 2060 carbon-neutral goal.Here,we used a satellite-and inventory-based approach,ecosystem models,and atmospheric inversions to estimate that the carbon sink was 33.12–37.84 TgC yr^(–1)during 2000–2015.The carbon sink induced by climate change and increasing CO_(2)levels largely overcompensated for a livestock grazing-induced carbon source of 0.38TgC yr^(-1).By 2060,the carbon sink is projected to increase by 38.3–74.5%under moderate to high emissions scenarios,with the enhanced vegetation carbon uptake outweighing the warming-induced permafrost carbon release.The restoration of degraded grassland could sequestrate an additional 9.06 TgC yr^(-1),leading to a total carbon sink of 57.78–70.52 TgC yr^(-1).We conclude that the Tibetan Plateau’s ecosystems absorbed two-and-a-half times the amount of its cumulative fossil CO_(2)emissions during 2000–2015 and that their carbon sinks will almost double in strength in the future,helping to achieve China’s pledge to become carbon neutral by 2060.展开更多
基金supported by grants from the Second Tibetan Plateau Scientific Expedition and Research(STEP)program(2024QZKK0301)the National Key Research and Development Program of China(2024YFF0809104)the National Natural Science Foundation of China(42425106).
文摘The greenhouse gas budget on the Tibetan Plateau remains unknown and the potential for methane(CH_(4))and nitrous oxide(N_(2)O)emissions from an intensifying livestock system and expanding surface water in offsetting terrestrial carbon dioxide(CO_(2))sinks are both of great concerns and uncertainties,which compromise an accurate assessment of Tibetan Plateau contribution to China’s ambitious climate goals by 2060s.Here we integrated greenhouse gas flux measurements at∼500 sites in empirical modeling approaches,emissions from the livestock sector with process-based biogeochemistry modeling to estimate CH_(4)and N_(2)O fluxes across terrestrial ecosystems and inland waters in 2000s and 2010s.We found that emissions from livestock and inland waters,predominantly contributed by CH_(4),compensated∼21%and∼13%of carbon sinks provided by forests and grasslands after adjusting carbon burial in sediments and riverine carbon export,respectively.The Tibetan Plateau then acted as an appreciable greenhouse gas sink that almost compensated for its contemporary anthropogenic emissions,making it nearly climate-neutral.The enhancement of terrestrial CO_(2)sinks in the 2060s under medium warming scenario would be counterbalanced by livestock CH_(4)emissions when the current overgrazing status continues.By transitioning to a livestock-forage balance and implementing mitigation initiatives to reduce livestock emission intensity,the greenhouse gas sink is projected to increase by more than 1.5 times.We suggested that a transition towards sustainable pastoralism illuminates the path to minimizing ecosystem greenhouse gas emissions and amplifying the role of the Tibetan Plateau in fulfilling China’s climate ambition.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research Programme(Grant Nos.2019QZKK0606,2022QZKK0101)the National Natural Science Foundation of China(Grant Nos.41901136,41922004,41871104)the Science and Technology Major Project of Tibetan Autonomous Region of China(Grant No.XZ202201ZD0005G01)。
文摘The contemporary carbon balance over the Tibetan Plateau is highly uncertain with a ten-fold difference between various estimates.In a warming world,the potential exists for a large carbon release from its permafrost which could compromise China’s 2060 carbon-neutral goal.Here,we used a satellite-and inventory-based approach,ecosystem models,and atmospheric inversions to estimate that the carbon sink was 33.12–37.84 TgC yr^(–1)during 2000–2015.The carbon sink induced by climate change and increasing CO_(2)levels largely overcompensated for a livestock grazing-induced carbon source of 0.38TgC yr^(-1).By 2060,the carbon sink is projected to increase by 38.3–74.5%under moderate to high emissions scenarios,with the enhanced vegetation carbon uptake outweighing the warming-induced permafrost carbon release.The restoration of degraded grassland could sequestrate an additional 9.06 TgC yr^(-1),leading to a total carbon sink of 57.78–70.52 TgC yr^(-1).We conclude that the Tibetan Plateau’s ecosystems absorbed two-and-a-half times the amount of its cumulative fossil CO_(2)emissions during 2000–2015 and that their carbon sinks will almost double in strength in the future,helping to achieve China’s pledge to become carbon neutral by 2060.
