Recently, Water Resources Research, a top journal in the field of water resources, published a paper of the research group led by Prof. Liu Junguo of School of Environmental Science and Engineering, SUSTech under the title of “Burden Shifting of Water Quantity and Quality Stress from Megacity Shanghai.”
The research group, after extensive studies, have found that developed countries are transferring carbon emissions pressure to developing countries through trade activities, but few studies have pointed out that developed regions are also shifting their water quantity and quality stress to underdeveloped regions in the form of trade. Prof. Liu Junguo’s research group, using the multi-regional input-output method and taking China’s largest city of Shanghai as an example, studied how megacities are shifting their water quantity and quality stress to other provincial administrative regions of China through virtual water trade.
The results show that in 2007 the consumption activities in Shanghai generated 11.6 billion cubic meters of fresh water consumption, 796,000 tons of COD emissions, and 16,200 tons of NH3-N emissions. And about 80 percent of water consumption and pollutant emissions from Shanghai’s consumption activities occurred in other provincial administrative regions of China. By selling products to Shanghai, some provinces consumed local water resources and polluted local water bodies to some extent. Specifically, 60 percent of Shanghai’s virtual water imports came from 13 provinces of extreme and severe water shortages, while 79 percent of COD and 75.5 percent of NH3-N were “outsourced” to 19 provinces with water quality stress.
Fig. 1 (a) Shanghai’s net virtual water import from other provinces (b) Shanghai’s outsourcing COD from other provinces (c) Shanghai’s outsourcing NH3-N from other provinces
The above research findings show that the burden shifting of water stress among provinces should be taken into consideration when implementing the “three red lines” (control targets for total water consumption, water use efficiency, and total pollutant emissions) of the strictest water resources management; Shanghai and the regions shifting their water stress to other regions should assume some responsibility and compensate the provinces that are relatively underdeveloped and are bearing the water resources stress; at the same time, Shanghai should actively explore ways to save water and reduce water pollution from the consumer perspective.
The above studies have received support from the National Natural Science Foundation and other fundations.
Download the article:
http://onlinelibrary.wiley.com/doi/10.1002/2016WR018595/full
Despite recent concerns about the effectiveness of wind power as a sustainable renewable energy source, international and interdisciplinary research efforts have shown that global wind speeds have been increasing, rather than decreasing.
Recently, Associate Professor Zhenzhong Zeng from the School of Environmental Science and Engineering at Southern University of Science and Technology (SUSTech), and his collaborators have made important progress in global change regarding terrestrial windspeed changes that were published in Nature Climate Change (IF= 25.170).
According to the global surface observation network, global wind speeds over land has been falling steadily since 1960, known as “global terrestrial stilling”. Global terrestrial stilling will seriously affect the efficiency of wind turbine power generation. Previous studies have suggested that global wind speed will continue to decline in the coming decades.
In their paper, Zeng and his collaborators discovered for the first time that after decades of global terrestrial stilling, global wind speeds over land reversed in around 2010, presenting a sharp upward trend, and recovered to levels around 1980 in a short span of eight years. The recent growth rate is three times the pre-2010 rate of decline, with North America, Europe and Asia showing the most marked changes.
The team also examined potential causes underlying global terrestrial stilling and its reversal. Previous studies had suggested a correlation with increased terrestrial roughness caused by urbanization and/or vegetation changes. However, Zeng et al. (2018 Environmental Research Letter) rejected the hypothesis of vegetation growth and change before analyzing the impact of urbanization and rejected this hypothesis. Zeng and his global collaborators have found that the variation in wind speed is determined mainly by driving forces associated with decadal variability of large-scale ocean/atmospheric circulations rather than increases in surface roughness.
If the present trend persists for at least another decade, power generated by wind turbines could increase by 37% by 2024, resulting in a +3% per decade increase of global-average capacity factor (mean power generated divided by rated peak power). This change is even larger than the projected change in wind power potential caused by climate change under multiple scenarios.
These research results are of great value to the global wind energy field, as they will be conducive to the development of the industry, developing wind energy into a major pillar of renewable energy. This paper provides a road map for further verification of the dynamic mechanisms, in order to improve the simulation of surface wind speeds according to IPCC climate models and weather models.
The lead and the corresponding author is Dr. Zhenzhong Zeng (Southern University of Science and Technology, Princeton University). The collaborators include Alan D. Ziegler at National University of Singapore, Timothy Searchinger and Eric. F. Wood at Princeton University, Long Yang at Nanjing University, Anping Chen at Colorado State University, Kunlu Ju at Tsinghua University, Shilong Piao at Peking University, Laurent Z. X. Li at Centre National de la Recherche Scientifique, Philippe Ciais at Laboratoire des Sciences du Climat et de l’Environnement, Deliang Chen at University of Gothenburg, Junguo Liu at Southern University of Science and Technology, Cesar Azorin-Molina at Centro de Investigaciones sobre Desertificación, Adrian Chappell at Cardiff University, and David Medvigy at University of Notre Dame.
The research is supported by the following funding: the Strategic Priority Research Program of Chinese Academy of Sciences, the start-up fund provided by Southern University of Science and Technology and Lamsam-Thailand Sustain Development, Lamsam-Thailand Sustain Development, the National Key Research and Development Program of China, and National Natural Science Foundation of China.
The link of the paper: https://www.nature.com/articles/s41558-019-0622-6.