Climate change impacts on Earth’s atmosphere have caused drastic changes in the environment of most regions of the world. The Middle East region ranks among the worst affected of these regions. This has taken forms o...Climate change impacts on Earth’s atmosphere have caused drastic changes in the environment of most regions of the world. The Middle East region ranks among the worst affected of these regions. This has taken forms of increasing atmospheric temperatures, intensive heat waves, decreased and erratic precipitation and general decline in water resources;all leading to frequent and longer droughts, desertification and giving rise to intensive and recurrent (SDS). The present conditions have led to increasing emissions of (GHG) in the earth atmosphere. All future projections especially those using (IPCC) models and emission scenarios indicate that the Middle East will undergo appreciable decrease in winter precipitation with increasing temperature until the end of this century both of which are inductive to increased dryness and desertification. Iraq as one of the countries of this region and due to its geographical location, its dependence mostly on surface water resources originating from neighboring countries, long years of neglect and bad land management put it in the most precarious and unstable position among the other countries of the region. Modelling studies have shown that Iraq is suffering now from excessive dryness and droughts, increasing loss of vegetation cover areas, increasing encroachment of sand dunes on agricultural lands, in addition to severe and frequent (SDS). These negative repercussions and their mitigations require solutions not on the local level alone but collective cooperation and work from all the countries of the region.展开更多
基于政府间气候变化专门委员会(IPCC)第四次评估报告(AR4)中的海气耦合模式实验,本文研究了温室气体辐射强迫达到4.5 W/m2(Representative Concentration Pathways,RCP4.5)未来情景下东亚地区季风气候变化,对4个海气耦合模式(FGOALS_s2....基于政府间气候变化专门委员会(IPCC)第四次评估报告(AR4)中的海气耦合模式实验,本文研究了温室气体辐射强迫达到4.5 W/m2(Representative Concentration Pathways,RCP4.5)未来情景下东亚地区季风气候变化,对4个海气耦合模式(FGOALS_s2.0(Flexible Global Ocean-Atmosphere-Land System model_s2.0)、GFDL_CM3(Geophysical Fluid Dynamics Laboratory Coupled Model v3)、MPI_ESM_LR(Max Planck Institute-Earth System Model-Low Resolution)和MIROC5(Model for Interdisciplinary Research on Climate v5))的模拟结果进行了对比。结果显示,各模式均能较好地模拟东亚地区的季风气候态特征,例如冬、夏季盛行风向,降水、热通量的季节和海陆分布特点及降水北进南撤特征。然而,各模式的模拟结果之间也存在差异,例如与再分析资料相比,FGOALS_s2.0模拟的风速偏大,GFDL_CM3模拟的降水较低,综合比较得出,GFDL_CM3对东亚地区气候变化的模拟效果最好。对未来气候的预测方面,4个模式给出较为一致的结论:未来100 a东亚季风的总体变化趋势为季风环流夏季风增强,冬季风减弱,夏季风速增加3.7%左右;降水增加,尤以陆地增加明显,东亚地区未来降水全年增加量约为4.62%;大部分地区热通量有增加的趋势,这是温室效应增强的结果。展开更多
Carbon footprint analysis is a method to quantify the life cycle Greenhouse Gases (GHGs) emissions and identify the measure to reduce climate change impacts. The Intergovernmental Panel on Climate Change (IPCC) has id...Carbon footprint analysis is a method to quantify the life cycle Greenhouse Gases (GHGs) emissions and identify the measure to reduce climate change impacts. The Intergovernmental Panel on Climate Change (IPCC) has identified that the global warming and climate change which is one of the most important issues in the domain of environment are caused by the excessive emission of Greenhouse Gases (GHG) mainly constituting Carbon dioxide (CO2), Methane (CH4) and Nitrous oxide (N2O). The municipal wastewater treatment plant receives wastewater for treatment and finally discharges the treated effluent. The emissions of GHG during the treatment of wastewater as well as during the treatment process of sludge and also for energy generation are known to be on-site GHG emissions. Off-site GHG emissions are generated due to transportation and disposal of sludge, off-site energy and chemical production. In Puducherry, the municipal wastewater is being treated using oxidation ponds, Upflow Anaerobic Sludge Blanket (UASB) and Sequencing Batch Reactor (SBR). Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are performed in a single reactor in a time control sequence. The emissions of GHG from the Oxidation ponds of 12.5 MLD, UASB reactor of 2.5 MLD and SBR of 17 MLD were assessed based on the IPCC guidelines and the total emissions of GHG in terms of equivalent of CO2 were compared. The performance of the SBR is more efficient and the emissions of GHG are less than the emissions in the UASB as well as in oxidation ponds. The emission of GHG in SBR is about 60% of the existing treatment systems of oxidation ponds and UASB thus a reduction of 40% GHG emission could be achieved.展开更多
气候变化问题是当今国际社会普遍关注的全球性环境问题之一.全球应对气候变化不仅涉及科学问题,也是国际政治经济共同涉及的问题.政府间气候变化专门委员会（Intergovernmental Panel on Climate Change,IPCC）通过汇总评估全球范围内...气候变化问题是当今国际社会普遍关注的全球性环境问题之一.全球应对气候变化不仅涉及科学问题,也是国际政治经济共同涉及的问题.政府间气候变化专门委员会（Intergovernmental Panel on Climate Change,IPCC）通过汇总评估全球范围内气候变化领域的最新研究成果.展开更多
Climate change has attracted significant attention due to its increasing impacts on various aspects of the world,and future climate projections are of vital importance for associated adaptation and mitigation,particul...Climate change has attracted significant attention due to its increasing impacts on various aspects of the world,and future climate projections are of vital importance for associated adaptation and mitigation,particularly at the regional scale.However,the skill level of the model projections over China in the past more than ten years remains unknown.In this study,we retrospectively investigate the skill of climate models within the Third(TAR),Fourth(AR4),and Fifth(AR5)Assessment Reports of the Intergovernmental Panel on Climate Change(IPCC)for the near-term projections of near-surface(2 m)air temperature changes in China.Those models are revealed to be skillful in projecting the subsequent climatology and trend of the temperature changes in China during 2002-2018 from several to ten years ahead,with higher scores for the climatology than for the trend.The model projections display cold biases against observations in most of China,while the nationally averaged trend is overestimated by TAR models during 2002-2018 but underestimated by AR4 models during 2008-2018.For all emission scenarios,there is no obvious difference between the equal-and unequal-weighted averages based on the arithmetic averaging and reliability ensemble averaging method respectively,however the uncertainty range of projection is narrowed after weighting.The near-term temperature projections differ slightly among various emission scenarios for the climatology but are largely different for the trend.展开更多
文摘Climate change impacts on Earth’s atmosphere have caused drastic changes in the environment of most regions of the world. The Middle East region ranks among the worst affected of these regions. This has taken forms of increasing atmospheric temperatures, intensive heat waves, decreased and erratic precipitation and general decline in water resources;all leading to frequent and longer droughts, desertification and giving rise to intensive and recurrent (SDS). The present conditions have led to increasing emissions of (GHG) in the earth atmosphere. All future projections especially those using (IPCC) models and emission scenarios indicate that the Middle East will undergo appreciable decrease in winter precipitation with increasing temperature until the end of this century both of which are inductive to increased dryness and desertification. Iraq as one of the countries of this region and due to its geographical location, its dependence mostly on surface water resources originating from neighboring countries, long years of neglect and bad land management put it in the most precarious and unstable position among the other countries of the region. Modelling studies have shown that Iraq is suffering now from excessive dryness and droughts, increasing loss of vegetation cover areas, increasing encroachment of sand dunes on agricultural lands, in addition to severe and frequent (SDS). These negative repercussions and their mitigations require solutions not on the local level alone but collective cooperation and work from all the countries of the region.
文摘基于政府间气候变化专门委员会(IPCC)第四次评估报告(AR4)中的海气耦合模式实验,本文研究了温室气体辐射强迫达到4.5 W/m2(Representative Concentration Pathways,RCP4.5)未来情景下东亚地区季风气候变化,对4个海气耦合模式(FGOALS_s2.0(Flexible Global Ocean-Atmosphere-Land System model_s2.0)、GFDL_CM3(Geophysical Fluid Dynamics Laboratory Coupled Model v3)、MPI_ESM_LR(Max Planck Institute-Earth System Model-Low Resolution)和MIROC5(Model for Interdisciplinary Research on Climate v5))的模拟结果进行了对比。结果显示,各模式均能较好地模拟东亚地区的季风气候态特征,例如冬、夏季盛行风向,降水、热通量的季节和海陆分布特点及降水北进南撤特征。然而,各模式的模拟结果之间也存在差异,例如与再分析资料相比,FGOALS_s2.0模拟的风速偏大,GFDL_CM3模拟的降水较低,综合比较得出,GFDL_CM3对东亚地区气候变化的模拟效果最好。对未来气候的预测方面,4个模式给出较为一致的结论:未来100 a东亚季风的总体变化趋势为季风环流夏季风增强,冬季风减弱,夏季风速增加3.7%左右;降水增加,尤以陆地增加明显,东亚地区未来降水全年增加量约为4.62%;大部分地区热通量有增加的趋势,这是温室效应增强的结果。
文摘Carbon footprint analysis is a method to quantify the life cycle Greenhouse Gases (GHGs) emissions and identify the measure to reduce climate change impacts. The Intergovernmental Panel on Climate Change (IPCC) has identified that the global warming and climate change which is one of the most important issues in the domain of environment are caused by the excessive emission of Greenhouse Gases (GHG) mainly constituting Carbon dioxide (CO2), Methane (CH4) and Nitrous oxide (N2O). The municipal wastewater treatment plant receives wastewater for treatment and finally discharges the treated effluent. The emissions of GHG during the treatment of wastewater as well as during the treatment process of sludge and also for energy generation are known to be on-site GHG emissions. Off-site GHG emissions are generated due to transportation and disposal of sludge, off-site energy and chemical production. In Puducherry, the municipal wastewater is being treated using oxidation ponds, Upflow Anaerobic Sludge Blanket (UASB) and Sequencing Batch Reactor (SBR). Wastewater treatment using Sequencing Batch Reactor (SBR) technology is one of the state-of-the art wastewater management systems. In this technology equalization, biological treatment and secondary clarification are performed in a single reactor in a time control sequence. The emissions of GHG from the Oxidation ponds of 12.5 MLD, UASB reactor of 2.5 MLD and SBR of 17 MLD were assessed based on the IPCC guidelines and the total emissions of GHG in terms of equivalent of CO2 were compared. The performance of the SBR is more efficient and the emissions of GHG are less than the emissions in the UASB as well as in oxidation ponds. The emission of GHG in SBR is about 60% of the existing treatment systems of oxidation ponds and UASB thus a reduction of 40% GHG emission could be achieved.
基金supported by the National Natural Science Foundation of China(41991284)the Second Tibetan Plateau Scientific Expedition and Research Program(2019QZKK0101)+1 种基金the National Key Research and Development Program of China(2018YFA0606501)the National Key Scientific and Technological Infrastructure Project“Earth System Science Numerical Simulator Facility”(Earth Lab)。
文摘Climate change has attracted significant attention due to its increasing impacts on various aspects of the world,and future climate projections are of vital importance for associated adaptation and mitigation,particularly at the regional scale.However,the skill level of the model projections over China in the past more than ten years remains unknown.In this study,we retrospectively investigate the skill of climate models within the Third(TAR),Fourth(AR4),and Fifth(AR5)Assessment Reports of the Intergovernmental Panel on Climate Change(IPCC)for the near-term projections of near-surface(2 m)air temperature changes in China.Those models are revealed to be skillful in projecting the subsequent climatology and trend of the temperature changes in China during 2002-2018 from several to ten years ahead,with higher scores for the climatology than for the trend.The model projections display cold biases against observations in most of China,while the nationally averaged trend is overestimated by TAR models during 2002-2018 but underestimated by AR4 models during 2008-2018.For all emission scenarios,there is no obvious difference between the equal-and unequal-weighted averages based on the arithmetic averaging and reliability ensemble averaging method respectively,however the uncertainty range of projection is narrowed after weighting.The near-term temperature projections differ slightly among various emission scenarios for the climatology but are largely different for the trend.
