Since Donald Trump became the president of the United States, whole world is ready for his drop on the Paris Agreement. However, the formal intervention still caused a broadly world reaction. Beside the negative influence on the political credit, international cooperation and potential effect on long term economic of the United States, Trump will not only take advantage of the political reputation building, but get another bargain chance to renegotiate of the Paris Agreement. In general, the United State withdrawal from the Paris Agreement will not change the low-carbon pathway and transformation trend of the global climate regime, but the long-term goal and the international cooperation on climate change will be impacted due to the budget cut on domestic climate change research and the donation cancelation on the multilateral environmental fund from the United States. As long as there is a renegotiation of the Paris Agreement, the common but differentiated principle of responsibility of the United Nations Framework Convention on Climate Change will be challenged again. In future, the climate change governance is still one of the main themes for the sustainable development. Instead of the governments, the multiple roles will improve their acting on climate change governance and local, non-governmental organizations will carry out more technical innovation and pragmatic cooperation. The capacity building on climate change research and awareness should be enhanced as a long-term work.

In the afternoon of June 1, 2017, the United States President Trump officially announced its withdrawal from the Paris Agreement, thus study on the reasons of withdrawal, the follow up impact and coping strategies became the focus of the international community. Based on the self-developed the United States policy evaluation model, this paper systematically evaluates the three gaps of global climate change mitigation, finance and governance after the United States declared its withdrawal from the Paris Agreement, and put forward China's response strategy and suggestion. The study shows that the United States' withdrawal from the Paris Agreement will impact on the existence and implementation of successive climate policies and make the United States' GHG emissions in 2030 reach 5.79 (5.60-5.98) billion tons of CO₂-eq, which is equivalent to a decrease of 12.1% (9.1%-15.0%) at the 2005 level and a rise of 1.64 (1.25-2.01) billion tons of CO₂-eq emission compared to the NDC scenario, and cause additional 8.8% to 13.4% of the global emission reductions deficit. The refusal of the United States to continue to meet its financial support obligations will also worse the situation of current climate finance mechanism. The global climate fund's funding gap will increase by US$ 2 billion, while the gap in long-term climate finance will increase by about US$ 5 billion per year. With at least 40% increase in GCF contributions from Japan and the European Union (EU), while an at least 25.2% increase of EU and its member states' overall financial support, can fulfill the financial deficit caused by the United States. The United States is an important party in the global climate governance, and the impact of the United States' withdrawal has spread to the main agenda of global governance, it is unrealistic to expect China-EU, BASIC plus, and so on to quickly fill the governance deficit caused by the United States at short time and the "low period" of global governance may inevitably last for a while. Although the international community is looking forward to China's leadership in global climate governance, China should have a clear understanding of the cost, benefits and feasibility of playing "leading role" and shall remain be cautious and determine its strategy in addressing climate through long-term plans. At the same time, China should focus more on domestic work, reach a strategic consensus on climate change, and preparing for "leadership" in long-term. China should also actively promote the international cooperation at all levels to find a way to deal with "three deficits" problem.

Based on the computable general equilibrium (CGE) model and scenario analysis, this article assesses the impacts of the United States' (U.S.) withdrawal from the Paris Agreement on China, European Union (EU) and Japan in terms of carbon emission space and mitigation cost under Nationally Determined Contributions (NDCs) and 2℃ scenarios due to changed emission pathway of U.S. The results show that, under the condition of constant global cumulative carbon emissions and fixed burden sharing scheme among countries, the failure of the U.S. to honor its NDC commitment to different degrees will increase its carbon emission space and decrease its mitigation cost. However, the carbon emission space of other parties, including China, EU and Japan, will be reduced and their mitigation costs will be raised. In 2030, under the 2℃ target, the carbon price will increase by 4.4-14.6 US$/t in China, by 9.7-35.4 US$/t in EU, and by 16.0-53.5 US$/t in Japan. In addition, China, EU and Japan will incur additional GDP loss. Under the 2℃ target in 2030, the GDP loss of China would increase by US$ 22.0 billion-71.1 billion (equivalent to 16.4-53.1 US$ per capita), EU's GDP loss would rise by US$ 9.4 billion-32.1 billion (equivalent to 20.7-71.1 US$ per capita), and Japan's GDP loss will rise by US$ 4.1 billion-13.5 billion (equivalent to 34.3-111.6 US$ per capita).

Combining qualitative study and quantitative study, this article analyzes the reasons why U.S. president Trump decided to withdraw from the Paris Agreement, assesses the impact of U.S. withdrawal from the Paris Agreement on the implementation of the Paris Agreement and China, and makes policy suggestions on how China should respond. Undoubtedly, U.S. withdrawal is a big event for global climate governance in the sense that it will exert multi-dimensional impacts on the implementation of the Paris Agreement. U.S. withdrawal seriously undermines the universality of the Paris Agreement, which is perceived as the backbone of global climate regime, aggravates the leadership deficit in global climate governance, sets a bad precedent for global climate cooperation, wins itself more emission right and lower cost of mitigation while squeezing other countries' carbon emission space and raising their cost of mitigation, make it more difficult for developing countries to mitigate and adapt to climate change, may cost the world the window of opportunity in climate mitigation, will compromise the quality of future IPCC reports and ultimately undermine the authority of future negotiations under the Paris Agreement, and finally makes the long term goal much tougher to achieve, even unlikely. In general, the framework of global climate governance will not collapse but will be shaken; the process of global climate governance will not be reversed but will be slowed. U.S. withdrawal poses a lot of challenges to China. One of them is the rising demand and pressure from international community that China should assume global climate leadership alone. In this context, China should achieve the most ambitious targets in the range of its Nationally Determined Contribution (NDC) domestically, and facilitates the reestablishment of shared global climate leadership, which means shifting from G2 to C5 in an active manner internationally. At the same time, China should work hard to pull U.S. back.

The entry into force of the Paris Agreement marks the transition of the global climate governance from the negotiation to the compliance. However, that does not mean global climate risk is under control, but rather faces new challenges. In this paper, the three shortcomings of the Paris Agreement are identified, Trump administration's weak climate willingness and their consequencesare are analyzed, and the climate policy possibility of the United States in the future are discussed. It's found that the Paris Agreement has three inherent deficiencies and thus the effectiveness of the Paris Agreement during the implementation process was still dependent on the compliance willingness and compliance capacity of the Parties. Trump administration's climate retreat could have negative impacts on the Parties' compliance willingness and compliance capacity. However, those adverse effects are only short-lived. The status of the United States in the international structure and its established low carbon transition trend will jointly determine Trump administration's withdrawal will not fundamentally shake the Paris Agreement. In the long run, the intention of the United States for global leadership, the domestic dynamics to address climate change, and the moral pressures from outside will inevitably lead the United States to return to the Paris Agreement.

The daily data of temperature, wind direction and wind speed during 2007-2009 of the two meteorological stations located in the east and west regions of Changsha city, as well as the land cover dataset, were analyzed for better understanding of the impact of urbanization on the temperature records of meteorological stations close to city. The differences of climatic factors between the two stations were contrastively analyzed and the urban biases of temperature data were estimated by using the modified urban impact indicators. The results showed that the monthly mean temperature (T_mean), mean maximum temperature (T_max) and mean minimum temperature (T_min) at two stations differed greatly, and the largest difference were up to 0.90℃, 0.83℃ and 1.34℃, respectively. As influenced by urban area and wind directions, significant difference of monthly urban impact indicator (△K) between the two stations was observed, and the average K of East station and West station were 2.01 and 1.50, respectively. There was seasonal variation of the K at each station, and the △K and △T of two stations were positively and significantly correlated. The largest urban warming in T_mean of East station and West station were observed in 2007, which were up to 0.63℃ and 0.45℃, respectively. It is necessary to adjust the temperature data when analyzing the long-term climate change and using station records to analyze the spatial change of climate because the temperature records of meteorological stations near cities were significantly influenced by urban size, wind direction and wind speed.

The Paris Agreement indicates "to hold the increase in the global average temperature to well below 2℃ above preindustrial levels and to pursue efforts to limit the temperature increase to 1.5℃ above pre-industrial levels to reduce the risk and impact of climate change". Then, the United Nations Framework Convention on Climate Change (UNFCCC) invite IPCC to provide a special report on impact and related pathways of greenhouse gases emissions for 1.5℃ global warming. Under 2℃ global warming, the risk of some types of extreme events will further increase; Some vulnerable systems, such as ecosystems and agricultural systems, will suffer more serious consequences. At the same time, the world will face more server consequences of sea surface level rise, coral reefs degradation and monsoon precipitation decrease. Regional responses to global warming with various magnitudes also show great differences. In general, limit temperature increase to 1.5℃ rather than 2℃ can further reduce risk of climate change. To understand 1.5℃related issues more clearly, higher resolution models and more experiments specifically designed for 1.5℃ global warming are needed in order to quantitatively analyze its impacts on natural and human systems at global and regional scales.

The annual vegetation phenology in the desert/grassland biome transition zone of Northern Hemisphere was deduced from the GIMMS NDVI 3g dataset and the spatio-temporal changes of phenology during 1982-2012 were studied. At the same time, the climatic driving factors of phenology change were also analyzed by coupling global meteorological reanalysis data. The results show that the vegetation phenology in each desert/grassland biome transition zone during 1982-1997 had different characteristics. However, the regular phenomenon of vegetation phenology changed after 1998. The end of growth season (EOS) in almost all desert/grassland biome transition zones of Northern Hemisphere became earlier during 1998-2012, which the rate is 0.41 d/a. The length of growth season (LOS) shortened in each region except for the Sahel, which the average shorten rate is 0.88 d/a. The correlation analysis between vegetation phenology and climatic factors show that the phenology of desert/grassland biome transition zone is affected by climate significantly and the main driving factors are different in each region. In the middle and high latitudes, the temperature is the key factor to limit the vegetation activity and the temperature rising can promote the start of growth season earlier. However, the precipitation increasing could weaken the growth of vegetation in these regions. In contrast, the water deficit that caused by the high temperature could shorten the vegetation growing season, and that is the key impact factor in the low latitudes of Northern Hemisphere. Finally, the relationship between phenology and climatic factors in different time-lags were also analyzed. The results show that the phenology change of desert/grassland biome transition zone is responded obviously to temperature change. In addition, there has a time lag effect in the response of phenology change to evapotranspiration. Nevertheless, this rule does not exist between phenology change and precipitation.

This study reviews the latest progress in research on climate change and water resources in the arid area of Northwest China, analyzes the cause of water resource changes within the region from the perspective of climate change and human activities, and summarizes future likely changes in water resources and associated adaptation strategies. The research shows that the climate in the region has experienced warming and wetting with the most significant warming in winter and the highest increase of precipitation in summer since 1961. Areas with the most significant warming trends include the Qaidam Basin, the Yili River Valley, Tacheng city. Spatially, the increasing trend in precipitation becomes increasingly significant from the southeast to the northwest and northern Xinjiang experienced the highest increase. Studies have shown a decrease in headwater of Shiyang River because runoff is mainly based on precipitation with a decrease trend. But an increase in western rivers was observed such Tarim River and Shule River as well as Heihe River due to rapid glacier shrinkage and snowmelt as well as precipitation increase in mountain area. Meanwhile unreasonable human activities resulted in decrease of runoff in the middle and lower reaches of Haihe River, Shiyang River and Kaidu River. Finally, recommendations for future studies are suggested that include characteristics of changes in extreme weather events and their impacts on water resources, projections of future climate and water resource changes, climate change attribution, the selection of adaptation strategies relating to climate change and social economic activities, and use of scientific methods to quantitatively determine water resource allocation.

Typical meteorological year (TMY) data were generated using two methods, i.e., Sandia and Danish methods. The load of a typical office building in Tianjin was simulated by the TRNSYS software based on the meteorological year data. The results showed that both Sandia and Danish methods can be well used to generate TMY in Tianjin. The TMY data were obviously changed under the conditions of climate change, and the impact of climate change in the heating period (November-March) was more obvious than that in the cooling period (June-September). Compared to the heating load during 1961-1990, the building heating load of 1981-2010 decreased by 5.2%, while the building cooling load increased by 1.6%. Therefore, the impact of climate change should be fully considered in the process of evaluating energy consumption of building design by using the TMY data. The generation and updating of TMY data should be quickly made. Compared to the cooling load during 1981-2010, the simulated building cooling load based on present TMY data decreased by 6.7%, while the building heating load increased by 4.7%. This shows building energy consumption estimation by using present TMY data in Tianjin may overestimate heating load but underestimate cooling load. Thus, it may decrease the body comfort of indoor environment and lead to waste of heating energy.

Measurement and calculation were performed on carbon emissions produced by the transportation system in 30 provinces of China from 2003 to 2014 based on energy consumption by taking the provinces as a research unit. The temporal-spatial evolution of China's provincial transport carbon emissions was explored. Results show that:carbon emissions grew rapidly, and the eastern regions were higher than the western, space characteristics of north-south direction showed an inverted-U curve, and the difference between regions tended to be slight; Xinjiang, Qinghai and Gansu were cold spots, while the hot spots were mainly distributed in the eastern coastal regions, and the gravity center of carbon emissions was concentrated in the southeast of Henan province, with the directional pattern of northeast-southwest and a trend towards the north; random factors of data variation in carbon emissions during different periods were different, and the structural difference was weakened with an increasing overall spatial effect range and a gradually enhanced spillover effect.