Based on the daily and monthly data of variables such as average temperature, maximum temperature, minimum temperature and precipitation at 2089 stations in China from 1961 to 2020, and the corresponding climate standard normals in 1981-2010 and 1991-2020, the difference of distribution between the two 30-year climate states were analyzed, followed by the investigation on the impact to the climate anomaly, the probability of extreme years (seasons), and extreme events. Under the new climate state, the three kinds of annual and seasonal temperature elements in China increase congruously, as well as the annual precipitation. Then the regional distribution difference of their corresponding climate anomaly will shrink. The anomaly of average wind speed and sunshine hours increase in the east of North China, the middle and north of East China and the southeast of Qinghai province. The probability of extreme high temperature year decreases and that of extreme low changes oppositely. Compared to the maximum temperature, the average and minimum temperature are more affected. Both of the probabilities of extreme heavy precipitation on the north and south rain belts in summer, and the probability of extreme weak precipitation in the middle and south of Northeast, North, the north of East and the east of Northwest China in winter significantly raise. The historical frequency of daily extreme high temperature, low temperature and heavy precipitation events at more than half of the stations in China has changed. The new climate state also weakens the growth rate of daily extreme high temperature events and accelerates the deceleration of daily extreme low temperature events. In the business, it is necessary to reanalyze extreme years (seasons) and extreme events.
In recent years, the change of extreme precipitation in China has received extensive attention, and related research has obtained a lot of results. However, the high-resolution precipitation data from the well-known datasets worldwide generally start around 1951 at present, lacking daily precipitation data in China in the early 20th century, so the characteristics and mechanism of extreme precipitation changes throughout China in the past 100 years are still unclear. Based on multiple sources of digital daily precipitation data from 1901 to 1950, through supplementing the previously unrecorded “no precipitation” and missing data, developing the quality control plans and carry out quality control work, filling in some missing and erroneous data, and combining the modern daily precipitation data since 1951, a dataset of daily precipitation was established for the past 119 years (1901-2019) of 60 city stations in China. The assessment results show that the stations in the eastern part of China are relatively dense, and the data integrity and correctness are better, but there are only a few stations in Western China and the integrity is low. The accumulated annual precipitation time series constructed by the dataset are basically consistent with the existing monthly precipitation datasets. Based on this dataset, it is found that there is no significant trend in precipitation and extreme precipitation at Chongqing station during the past 119 years, and the centennial long-term change characteristics of extreme precipitation in China can be further analyzed by using this dataset.
Using the observational data and simulation results from the Coupled Model Intercomparison Project Phase 6 (CMIP6), precipitation changes in Northwest China during 1979-2019 and under future global warming conditions are studied. Observations show that annual mean precipitation increased significantly in the arid and semi-arid areas of Northwest China over 1979-2019. Precipitation increased significantly in all seasons, with the largest increase in autumn. CMIP6 projection simulations show that precipitation in Northwest China will continue to increase from 2015 to 2100 along with global warming. Compared with that of the other regions in China, the increase of precipitation percentage is the largest in Northwest China. According to the projection of multi-mode ensemble mean, under the SSP2-4.5 and SSP5-8.5 scenarios, the increasing rates of annual mean precipitation in Northwest China are about 1.6%/(10 a) and 3.0%/(10 a), respectively. By the end of the 21st century, the annual mean precipitation in Northwest China will increase by ~13.7% (37 mm) for SSP2-4.5 and ~25.8% (78 mm) for SSP5-8.5. The seasons with the largest increase in precipitation are summer for SSP2-4.5 and spring for SSP5-8.5. Considering that evaporation in Northwest China will also increase with global warming, the annual mean net precipitation in Northwest China will increase by ~1.4% for SSP2-4.5 and ~4.9% for SSP5-8.5 at the end of the 21st century. Consequently, the increase of near surface soil moisture in Northwest China are ~10% for SSP2-4.5 and ~20% for SSP5-8.5. These results indicate that there is a significant wetting trend in Northwest China in the future. Further analysis also shows that future precipitation increasing in Northwest China are due to decreases of geopotential heights at the lower troposphere, which enhances upward motions.
Based on statistically downscaled daily precipitation, maximum and minimum temperature of five GCMs in CMIP5, the standardized precipitation evapotranspiration index (SPEI) and the Intensity-Area-Duration (IAD) method were used to investigate spatial and temporal variations of drought events in Central Asia under the 1.5℃ and 2.0℃ global warming scenarios. Cropland exposed to droughts in the warming world was estimated by applying the GlobeLand30 land use dataset with 30 m resolution. Both precipitation and potential evapotranspiration are projected to increase under the two warming scenarios compared with the reference period (1986-2005). Frequency, intensity, and areal coverage of total drought events are projected to increase under the 1.5℃ and 2.0℃ warming levels, among the total drought events, frequency and area of moderate droughts are projected to decrease, but those of severe and extreme severe droughts will substantially increase. Annual averaged cropland exposed to droughts was 115000 km2 in 1986-2005 in Central Asia. Cropland exposed to droughts will increase to 179000 and 286000 km2 under the 1.5℃ and 2.0℃ warming scenarios, respectively, with the most significant increase of exposure to extreme severe droughts. Under the 1.5℃ and 2.0℃ global warming scenarios, the drought trend in Central Asia will continue increase, especially for the extreme droughts. The results show that droughts will seriously threaten agricultural production and food security in Central Asia, which calls for long-term mitigation and adaptation measurement for drought events.
There is a huge gap between the seismic fortification level of urban and rural housing buildings in China. The population exposed to low fortification rural areas and high-density cities are faced with high seismic risk. Therefore, it is of great significance to analyse the future urban and rural population and their exposure characteristics. Based on the data of the sixth national population census, this paper uses seismic intensity distribution and the population development environment (PDE) model to simulate the urban and rural population exposure to earthquake disaster of China’s city level units from 2010 to 2100 under five shared socio-economic scenarios (SSPs). The results show that: (1) Except for the continuous increase of urban population under SSP3, other SSP paths’ number of urban population in various regions increased first and then decreased, and rural population is declining due to urbanization; (2) The spatial distribution of high and medium high population exposure levels in urban and rural areas is similar, concentrated in North China, southwestern and eastern coastal areas of China; (3) Compared with fortified urban areas, the exposure level of non-fortified rural areas is high, and the number of high exposure areas are large. In the future, the exposure level of urban population will rise, while the exposure level of rural population will gradually decrease.
As global crises, the similarities in the scope, effects and causes of COVID-19 and the climate crisis may cause the effects of the two crises to overlap, while the differences between the two may lead to mutual interference in response policies, leading to more severe compounding risks. This paper provides a comprehensive analysis of the compounded risks of COVID-19 and climate crisis facing the world, identifying the impacts of COVID-19 on the global climate change adaptation process and the place of adaptation in countries’ post-epidemic green recovery plans. The study shows that adaptation is currently less considered in the global green recovery, which offers opportunities to simultaneously restore the economy and enhance climate resilience. If transformative adaptation can be considered in green recovery, it will greatly enhance the resilience and capacity of socio-economic systems to withstand shocks such as climate change, and achieve more sustainable and resilient economic development in the aftermath of the epidemic.
Seriously vulnerable to climate change, the Belt and Road countries are in urgent need of adaptation technologies transferred from other countries to combat climate change. Assessment of technology needs is a prerequisite for successful technology transfer. In this paper, a database of adaptation technology needs was established, by utilizing the Technology Need Assessment (TNA) reports submitted by the Belt and Road countries under the Cooperative Patent Classification (CPC). Four indicators, (a) how many times a certain technology is requested, (b) the number of countries which put forward a certain technology, (c) the GDP a certain technology can cover, (d) the population a certain technology can benefit, and two analytical perspectives, both regional and technical, were used in evaluating the technology needs. Four kinds of adaptation technologies were determined to be of general concern: agriculture, forestry, animal husbandry, and fishery production (Y02A-40), water harvesting, water conservation, and efficient water use (Y02A-20), adaptation technologies in coastal areas and river basins (Y02A-10), and technologies that contribute indirectly to climate change adaptation (Y02A-90). However, different Belt and Road countries have different adaptation technology needs due to their unique geographic location and socioeconomic circumstances. Oceania, Latin America and the Caribbean, and some Asian countries have raised concerns regarding the need for technologies for protecting and renovating their domestic infrastructure (Y02A-30) because their infrastructure is greatly affected by climate change. High temperatures and precipitation due to climate change have exacerbated disease outbreaks in water bodies and air, so Asia, Oceania, Latin America, and the Caribbean are in need of technologies to protect human health from extreme weather (Y02A-50). In order to facilitate effective technology transfer along the Belt and Road and improve countries’ ability to adapt to climate change, it is imperative to invest in the research and development of climate adaptation technologies, concentrating on the needs of technology recipient countries, and tap into the Belt and Road’s existing network of technology transfer centers.
In this study, the research results on the climate change and its impact as well as adaptation in the Beijing-Tianjin-Hebei (BTH) urban agglomeration since 2000 are systematically summarized. The results show that the annual average temperature and extreme high temperature of BTH urban agglomeration have obviously increased, and annual precipitation has weakened since 1960s. Meanwhile, the extreme precipitation index has decreased until the 2010s. The climate change in the BTH is jointly affected by global warming, and urbanization. Urbanization has accelerated the warming trend in the BTH, increased the frequency and intensity of extreme high temperature and extreme heavy precipitation, and thus resulted in high climate risk. Under the RCP4.5 scenario, it is projected that the extreme high temperature index and the extreme heavy precipitation index will increase in the BTH in the middle and late 21st century. When the global temperature rises by 1.5℃ in the future, the risk of high-intensity extreme warm events will increase by nearly three times, and the risk of high-intensity extreme precipitation events will increase by nearly two times. In the future the coordinated development of BTH urban agglomeration will face more severe risks such as high temperature and heat wave, heavy precipitation, water shortage and sea level rise. Therefore, it is quite urgent for the BTH urban agglomeration to adapt to climate change, so as to maintain the sustainable development. At present, huge progress has been made in the adaptation strategies, but there are still some deficiencies in their applicability and pertinence. This study puts forward the prospects for future research. The feedback of urbanization on climate change should be deeply investigated. The refined projection technology of climate risk under the joint effect of global climate change and urbanization should be developed. The systematical impact studies of climate change on cities and the vulnerability of different industries need to be conducted. The greenhouse gas monitoring and evaluation technology should be strengthened. The strategies, paths and technologies to adapt to climate change should be further studied.
The European Union (EU) has continuously explored how to reduce greenhouse gas emissions through the combination of carbon pricing and mandatory regulation since 1997. It has gradually established a relatively mature policy framework which includes Emission Trading System (ETS) and Effort Sharing Regulation (ESR). Over the last decade, China has made significant progress in controlling greenhouse gas emissions through ETS. It is reported that China’s national-wide carbon market was launched in 2021, while regulations that aim to bind emissions from non-traded sectors are still absent. Therefore, learning the EU’s experience in setting and assigning emissions targets would be helpful for China in establishing a coherent framework for limiting the greenhouse gas emissions across all economic sectors. This paper primarily focuses on explaining and analyzing the updated EU-wide reduction target of the ESR sectors and how target would be distributed to specific member states, with the aim of summarizing the EU’s experience in controlling greenhouse gas emissions of non-ETS sectors. The coordination between ESR and other existing policies, namely the flexibility of ETS and Land Use, Land Use Change and Forestry (LULUCF) should also be demonstrated. Suggestions such as gradually establishing an overarching system which involves ETS as well as legally-binding emissions targets, for controlling the aggregate carbon emissions would be proposed in the end.
Carbon capture and storage (CCS), as one of the important means to solve the global climate change problem, can effectively reduce CO2 emissions while retaining existing fossil energy assets. China is still reliant on coal power as the primary power supply source. Therefore, as a major carbon-emitting country, China has considerable potential for CCS applications. Economics is critical for CCS deployment. In this study, the levelized cost of electricity (LCOE) at province level was calculated for operational power plants after post-combustion carbon capture (CC) retrofitting. The costs of captured CO2 and avoided CO2 were then compared. The economics of coal-fired power plants with bioenergy with carbon capture retrofitting (BECC) were also analyzed. The study revealed that CC retrofitting leads to a 57.51% to 93.38% increase in the LCOE of coal power. CC retrofitting is economical in North and Northwest China (except Qinghai province) where coal prices are low. However, BECC retrofit is more suitable for coal-fired power plants in Central China where biomass prices are low. Therefore, the variation in the resource conditions among provinces should be considered when promoting CC and BECC retrofits. Compared with other power sources, coal-fired power generation becomes much more expensive after retrofits, and the current carbon market is not sufficiently developed to support the retrofits. The development of the carbon market with effective carbon price signals and proper power market mechanism is critical to the rollout of CCS in China. In addition to coal price and utilization hours, the initial investment cost and efficiency penalty of carbon capture retrofitting are also important influencing factors. With the development of new generation capture technologies with low cost and low energy consumption, the economics of coal-fired power plants with retrofitting will be further improved.
Energy transition is a key measure to promote the realization of the “Dual Carbon” goals. A comprehensive evaluation model was constructed for energy transition in Guangdong-Hong Kong-Macao Greater Bay Area (GBA). Then the baseline scenario, the transition scenario and the deep transition scenario were designed to evaluate the impact of energy transition on the economy industry, environmental positive externality, and health benefit of the GBA. The results are as follows. (1) The clean replacement of energy will promote the carbon emission peak time of the transition scenario and the deep transition scenario to 2025 and 2022, respectively, and the carbon emissions are reduced by 22.0% and 35.9% respectively, compared with the 2035 baseline scenario. Among them, the clean replacement of electricity contributes to a reduction of 59 million tons of carbon emissions, accounting for 53% of the entire society’s emissions reductions. (2) The transition and upgrading of industries and the optimization of investment structure will promote a GDP growth of 0.68% in the transition scenario compared with the 2035 baseline scenario. However, in the deep transition scenario, the carbon restrictions are too strict, resulting in a GDP loss of 0.34%. (3) The energy transition has positive externalities to the environment. Compared with the baseline scenario, SO2, NOX, PM2.5, PM10 will be reduced by 35%, 20%, 36% and 37%, respectively in the transition scenario in 2035, bringing CNY 15.56 billion of health benefit, accounting for about 0.05% of the GDP of the GBA. Comprehensively considering the economic, environmental, health impact of the energy transition on the GBA, the economy of transition scenario is the best, and it will bring 0.73% of economic benefit in 2035. The GBA should set a reasonable carbon emission reduction target, steadily promote the process of energy transition, and achieve the green energy transition and the coordinated development of energy, economy and environment.