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- Yu, ChaoQing, et al.
(författare)
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Managing nitrogen to restore water quality in China
- 2019
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Ingår i: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 567:7749, s. 516-520
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Tidskriftsartikel (refereegranskat)abstract
- The nitrogen cycle has been radically changed by human activities(1). China consumes nearly one third of the world's nitrogen fertilizers. The excessive application of fertilizers(2,3) and increased nitrogen discharge from livestock, domestic and industrial sources have resulted in pervasive water pollution. Quantifying a nitrogen 'boundary'(4) in heterogeneous environments is important for the effective management of local water quality. Here we use a combination of water-quality observations and simulated nitrogen discharge from agricultural and other sources to estimate spatial patterns of nitrogen discharge into water bodies across China from 1955 to 2014. We find that the critical surface-water quality standard (1.0 milligrams of nitrogen per litre) was being exceeded in most provinces by the mid-1980s, and that current rates of anthropogenic nitrogen discharge (14.5 +/- 3.1 megatonnes of nitrogen per year) to fresh water are about 2.7 times the estimated 'safe' nitrogen discharge threshold (5.2 +/- 0.7 megatonnes of nitrogen per year). Current efforts to reduce pollution through wastewater treatment and by improving cropland nitrogen management can partially remedy this situation. Domestic wastewater treatment has helped to reduce net discharge by 0.7 +/- 0.1 megatonnes in 2014, but at high monetary and energy costs. Improved cropland nitrogen management could remove another 2.3 +/- 0.3 megatonnes of nitrogen per year-about 25 per cent of the excess discharge to fresh water. Successfully restoring a clean water environment in China will further require transformational changes to boost the national nutrient recycling rate from its current average of 36 per cent to about 87 per cent, which is a level typical of traditional Chinese agriculture. Although ambitious, such a high level of nitrogen recycling is technologically achievable at an estimated capital cost of approximately 100 billion US dollars and operating costs of 18-29 billion US dollars per year, and could provide co-benefits such as recycled wastewater for crop irrigation and improved environmental quality and ecosystem services.
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| 2. |
- Zhang, Chi, et al.
(författare)
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Five tips for China to realize its co-targets of climate mitigation and Sustainable Development Goals (SDGs)
- 2020
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Ingår i: Geography and Sustainability. - : Elsevier BV. - 2096-7438 .- 2666-6839. ; 1:3, s. 245-249
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Tidskriftsartikel (refereegranskat)abstract
- In 2018, a total of US$166 billion global economic losses and a new high of 55.3 Gt of CO2 equivalent emission were generated by 831 climate-related extreme events. As the world's largest CO2 emitter, we reported China's recent progresses and pitfalls in climate actions to achieve climate mitigation targets (i.e., limit warming to 1.52 degrees C above the pre-industrial level). We first summarized China's integrated actions (2015 onwards) that benefit both climate change mitigation and Sustainable Development Goals (SDGs). These projects include re-structuring organizations, establishing working goals and actions, amending laws and regulations at national level, as well as increasing social awareness at community level. We then pointed out the shortcomings in different regions and sectors. Based on these analyses, we proposed five recommendations to help China improving its climate policy strategies, which include: 1) restructuring the economy to balance short-term and long-term conflicts; 2) developing circular economy with recycling mechanism and infrastructure; 3) building up unified national standards and more accurate indicators; 4) completing market mechanism for green economy and encouraging green consumption; and 5) enhancing technology innovations and local incentives via bottom-up actions.
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