Based on long time series dataset of snow depth in China, ERA-5 albedo data, and CESM-CAM5 radiative kernel data, the radiative forcing of snow cover in China from 1988 to 2016 was analyzed, and its atmospheric carbon equivalent was then calculated by the approach applied in DICE/RICE model. The climate regulation service of annual mean snow cover and its spatiotemporal change were subsequently analyzed. The results show that the contribution of snow cover in China to the global radiative forcing is -0.22 (±0.01) W/m2, and the equivalent reduction of atmospheric carbon is 17 (±1) Gt C. By applying the current carbon price, the economic value of average climate regulation service alone can reach 3.9 (±2.1) trillion CNY. Meanwhile, it was also found that the carbon equivalent of snow cover climate regulation services decreases at a rate of 66.7 million t/a in China, which is equivalent to an annual loss of 15.0 (±1.2) billion CNY. The cumulative value loss is 410 (±32.8) billion CNY through 29 years. Division from climate regulation function of snow cover in China is finally proposed.
Under a warming climate, increasing forest fires in the Greater Hinggan Mountains in Northeast China has led to the degradation of permafrost and recovery and succession of vegetation, obviously impacting on service functions of the forest ecosystem. In this study, Mangui and Alongshan in the northern Greater Hinggan Mountains were chosen as the study areas. Through quantitative methods, we calculated the benefits and losses of CO2 fixation and O2 release by the forest ecosystem; purifying the environment, including the absorption of SO2 and dusts; hydrological benefits, including flood control and water conservation; microclimate benefit loss; wildlife conservation and recreational benefits. Significant losses of ecosystem service values have occurred after fires in Mangui and Alongshan. The losses in the benefits of CO2 fixation and O2 release and purifying the environment were the two largest, accounting for 42.34% and 41.94% of the total benefit loss, respectively. The losses in the wildlife conservation benefits were the least (0.80%). Those in microclimatic, recreational and hydrological benefits, accounted for 8.61%, 3.49%, and 2.82%, respectively. Even if the coniferous forest ecosystem restored to the broad-leaved forest ecosystem after the fire, the loss in the benefit of purifying the environment could still reach 69.3%. Therefore, it is essential to systematically protect coniferous forests in permafrost areas and effectively reduce the occurrences of forest fires, so as to maintain the stability, sustainability and service ability of forest ecosystem in permafrost regions.
The Lancang-Mekong River basin flows southward across 25 degree of latitude with large climatic variations between the upstream and downstream. The concurrent drought and wet events will affect the water resources cooperation potential between upstream and downstream countries. Based on the Princeton precipitation dataset and global climate model data, the standardized precipitation index and Copula function were used to investigate the impacts of climate change on concurrent drought, concurrent wet and concurrence of different dry and wet conditions during the historical period (1982-2016) and future period (2021-2090) in the upstream and downstream of the Lancang-Mekong River basin. The results showed that compared with the historical period, the Lancang-Mekong River basin shows the similar change trend under the scenarios of RCP4.5 and RCP8.5 in the future period: the probability of concurrent wet will gradually increase (maximum 199.5%), and the probability of concurrent drought will gradually decrease (minimum -35.9%), and the probability of uneven water resource situation will greatly reduce in all periods (-53.1% - -42.5%). The results indicate that water resources cooperation between the upstream and the downstream of the Lancang-Mekong River basin may be adversely affected by climate change, and there is an urgent need for adaptation strategy to address water resources cooperation in the Lancang-Mekong River basin.
In recent years, scientists have proposed targeted geoengineering for ice sheets to enhance their stability and slow their mass loss, reducing their contribution to sea level rise at source. It promises to buy hundreds of years to combat climate change and protect coastlines. Ice sheet geoengineering works mainly on ice bottom and ice shelf-ocean interface. The main approaches include: 1) draining or freezing the water from the bottom of the glacier to dry the ice bed and enhance the friction of the glacier bottom; 2) making artificial islands in the sea to support floating ice shelves; 3) building an underwater barrier in front of the ice shelf to keep warm water from reaching the ice bottom to slow its melting. Ice sheet geoengineering includes numerical simulation, scheme design, engineering test, and political and legal research. International research teams have been carrying on numerical simulation and scheme design research. The research of engineering experiment and politics and law has not started yet. This paper predicts that the difficulty ladder of engineering test may be from laboratory test to small scale field test, then to outlet glaciers of Greenland ice sheet, and finally to outlet glaciers of Antarctic ice sheet. Targeted geoengineering for ice sheets is likely to become a new field of global change research in 21st century.
The cryosphere provides important resources for the socio-economic development in the cold and arid regions, which have been deeply impacted by climate change. Considering an increasing in anthropogenic needs and scarcity of cryospheric resources, their proper use is one of the core issues to ensure sustainable development in the regions. This paper puts forward an approach based on the perspective of “resources-assets-capital (RAC)”, by which management of cryospheric resources is discussed along with its ownership and capitalization for socio-economic development as the core process of cryosphere services. For the purpose of providing the decision-makers with scientific evidence for spatial decision, the spatial patterns of potential utilities, on the aspects to provide benefits to population, economics and environment in China, have been analyzed. Synergies between the potentials are also presented. The results show that most of Northeast China, the west of Xinjiang and the south of Tibet are gathering areas of river basins with high-level population and economic potential, while North China, Northeast China, the west of Xinjiang, the east edge and south of Tibet are gathering areas of river basins with high synergies. Based on the identification of the utility potential of “population-economy-ecology”, it is helpful to implement “quality improvement” and “efficiency enhancement”, and whereby sustainable use of cryospheric resources could be developed.
As the Earth system enters the Anthropocene, the cryosphere is rapidly undergoing shrinkages, exerting the impacts on regional ecological security and socio-economic development. Resilience thinking aims to reduce vulnerability, maintain and foster the persistence, adaptability, and transformability of complex adaptive social-ecological systems. By facilitating the research and practice on the socio-ecological system resilience in the cryosphere affected areas, it is of far-reaching significance to address the impact of climate change related cryosphere changes and achieve regional sustainable development. This paper identifies the impact of changes in the cryosphere process and function on relevant socio-ecological systems in the context of climate change, summarizes the main research and practice on resilience over cryosphere affected area, including high mountain and surrounding areas, polar regions, and coastal regions, and further discusses the resilient pathways over the cryosphere affected area. In general, the resilience building over cryosphere affected area needs to combine mitigation, adaptation and transformation, and establish series of robust systems including monitoring, assessing, early warning and decision-making so as to navigate the system toward more resilient and sustainable pathway.
In order to know how regional averaged cloud top height (CTH) responded to the past climatic change, the spatial and temporal variations of CTH based on MODIS data (MOD03_08_v6.0) from March 2000 to February 2018 were analyzed. The results showed that the CTH in East Asia was higher in the southwest and lower in the northeast. The annual mean CTH was found to increase in East Asia at the rate of 0.020 km per year, of which, 0.035 km per year over the eastern land and 0.034 km per year over the eastern sea. The CTH changes statistically correlated with the sea surface temperature changes over the eastern sea (r=0.68), which indicates that the CTH changes may be affected by the underlying surface. Statistically significant increasing trend of annual mean CTH was found in the latitude zone of 30°-40°N. Furthermore, CTH showed decreasing trends of about -0.030 km per year in the Middle-Lower Yangtze River basin, Tarim basin, Turpan basin and northeastern Sichuan basin in summer since more low cloud formations benefited to the decrease of CTH. In winter, the decreasing trend of CTH was found over the north of 40°N, whereas the increasing trend was found over the south of 40°N in East Asia.
In the context of water level data of Qinghai Lake, meteorological observational data including temperature, precipitation and evaporation in its basin and climate indexes such as plateau monsoon and westerly circulation from 1961 to 2015, the characteristics of water level fluctuation of Qinghai Lake were analyzed, influence mechanism of plateau monsoon, westerly circulation, vegetation cover, runoff and permafrost degradation on water level fluctuation of lake level were revealed, the quantitative evaluation model on water level changes of Qinghai Lake were established. The water level in Qinghai Lake showed a mutation from descending to rising in 2004 and a continuous rising for 11 years after 2005. The fluctuation of water level had 8 years and 21 years significant periods. Plateau monsoon enhancement and westerly circulation weakening, climate warming and wetting, vegetation restoration, permafrost degradation and runoff increasing, all brought about water level rising continuously after 2005. Quantitative evaluation model based on water balance principle can reflect the influential effect on water level fluctuation caused by precipitation, runoff and evaporation in the previous and current year objectively.
Carbon capture, utilization and storage (CCUS) is regarded as a very promising technology to reduce CO2 emission worldwide. It is a win-win strategy to coordinate economic development and environment to achieve effective carbon storage without changing the energy structure. The potential and prospects of CCUS technology are analyzed in the main Belt and Road Initiative (BRI) countries in this paper, based on the mechanism of CO2 storage in different formation, and a new evaluation method of CO2 storage capacity. The result shows that the main BRI countries have great CO2 storage potential of around 620 Gt. Currently, although CCUS technology is in the initial stage, with the support of government investment and policies, it will make a great contribution to the development of green and low-carbon economy in these countries.
Under the background of achieving China’s targets of Nationally Determined Contributions (NDC), a recursive dynamic Computable General Equilibrium (CGE) model with distinguished disaggregation in the electric power sector was developed to simulate the implementation effects and economic impacts of different designs of carbon trading mechanism for the national carbon market. Results show that national carbon market can help China to achieve the NDC targets and reduce the negative impacts of carbon emission reduction on GDP growth. Comparing with the rule of grandfathering allocation based on carbon emission, allocating initial carbon allowance freely under the rule of benchmarking allocation based on carbon-intensity can decrease carbon price, increase the volume of trading allowance and enlarge the scale of the carbon market. Allocating initial carbon allowance by auctioning will cause larger mitigation cost for the industries covered by the carbon market but can increase government revenue. Levying carbon tax on industries and households not covered by the carbon market can control their carbon emission effectively, increase government revenue, reduce the carbon trading price and promote the achievement of China’s NDC targets. The national carbon market will restrain thermal power industry whereas promote the development of clean energy power generation industries to different extent.
The power sector is a major carbon emissions source from fossil fuel combustion, and it plays an important role in controlling China’s emissions and achieving emissions peak target. In this paper, learning curve tool is used to evaluate the development of wind power and solar PV power as the two most promising renewable sources, while bottom up calculating method is used to analyze other technologies’ developments under current policy scenario and enhanced policy scenario. The carbon emissions under two policy scenarios are calculated before 2035, and it is found that carbon emissions peak around 2030 with non-fossil fuels accounting for 44% in total power generation under current policy scenario, while they peak before 2025 with non-fossil fuels taking a higher share of 51% at 2030 under enhanced polices. The developments of renewables are major drivers lowering the emissions from power sector, contributing 45%, 54% and 62% of the total emission reductions at 2025, 2030 and 2035 respectively. On the other hand, though the coal power capacity still sees room to grow from the perspective of safeguarding the power supply, it is still necessary to enhance the control on coal power capacity and make best efforts to keep it under 1100 GW.
China attaches great importance to climate change adaptation, implements the principle of equal attention to mitigation and adaptation, and has issued a series of policy documents such as strategies, plans and action programs related to climate change adaptation. However, China’s policies and actions to climate change adaptation are at the initial stage and are facing challenges such as lack of laws and regulations, inadequate monitoring and evaluation, and imperfect organizational coordination mechanism. The types, quantities and intensity of adaptation policies are much weaker than mitigation policies as well. In order to improve the framework design of climate change adaptation policies and mechanisms, this paper reviews relevant research, international mechanism of adaptation to climate change under the United Nations Framework Convention on Climate Change, and the design of adaptation policies and mechanisms of major countries, and constructs a closed-loop framework of adaptation, and summarizes the reference and enlightenment for China from international policy and mechanism of adaptation from five aspects: legislation construction, formulation of adaptation strategies and plans, monitoring and evaluation, coordination mechanism and financial mechanism. This paper provides relevant suggestions for establishing and improving the framework design of climate change adaptation policies and mechanisms in China, including the establishment and improvement of the legal system on climate change adaptation, constructing a national policy system for climate change adaptation, improving the design of national climate change adaptation mechanism, supporting capacity building for climate change adaptation, promoting international cooperation on climate change adaptation.