From planetary to regional boundaries for agricultural nitrogen pollution
From planetary to regional boundaries for agricultural nitrogen pollution
复制标题
农业氮污染从行星边界到区域边界
作者：
L. Schulte;A. Beusen;A. Bouwman;W. de Vries
农业过量使用氮会导致全球环境问题1，甚至有人认为已经超出了安全的地球边界2。然而，早期对地球氮边界的估计3,4并未考虑生态系统对氮污染和农业氮损失敏感性的空间变异性。在这里，我们使用空间明确的模型根据陆地和水生生态系统富营养化以及地下水中硝酸盐的阈值建立农业氮盈余的区域边界。我们估计了农业氮污染的区域边界，并发现了农业氮的过度使用和强化的空间。就所有阈值而言，全球氮盈余边界总计为每年 43 兆吨氮，比当前（2010 年）氮盈余（每年 119 兆吨氮）低 64%。在环境阈值未超过的地区，允许氮盈余增加以缩小产量差距，将全球氮边界提升至每年 57 兆吨。在不跨越区域和行星氮边界的情况下养活世界需要大幅提高氮利用效率，同时减少污水等非农业氮源。这就需要采取协调行动，认识到农业系统的异质性、非农业氮损失和环境脆弱性。对农业氮污染的区域和全球边界进行建模发现，全球氮过剩边界低于当前的氮过剩边界。
Excessive agricultural nitrogen use causes environmental problems globally1, to an extent that it has been suggested that a safe planetary boundary has been exceeded2. Earlier estimates for the planetary nitrogen boundary3,4, however, did not account for the spatial variability in both ecosystems’ sensitivity to nitrogen pollution and agricultural nitrogen losses. Here we use a spatially explicit model to establish regional boundaries for agricultural nitrogen surplus from thresholds for eutrophication of terrestrial and aquatic ecosystems and nitrate in groundwater. We estimate regional boundaries for agricultural nitrogen pollution and find both overuse and room for intensification of agricultural nitrogen. The aggregated global surplus boundary with respect to all thresholds is 43 megatonnes of nitrogen per year, which is 64 per cent lower than the current (2010) nitrogen surplus (119 megatonnes of nitrogen per year). Allowing the nitrogen surplus to increase to close yield gaps in regions where environmental thresholds are not exceeded lifts the planetary nitrogen boundary to 57 megatonnes of nitrogen per year. Feeding the world without trespassing regional and planetary nitrogen boundaries requires large increases in nitrogen use efficiencies accompanied by mitigation of non-agricultural nitrogen sources such as sewage water. This asks for coordinated action that recognizes the heterogeneity of agricultural systems, non-agricultural nitrogen losses and environmental vulnerabilities. Modelling of regional and planetary boundaries for agricultural nitrogen pollution finds that the global nitrogen surplus boundary is lower than the current nitrogen surplus.
影响因子：
30.7
作者：
Heck, Vera;Gerten, Dieter;Popp, Alexander
通讯作者：
Popp, Alexander
影响因子：
6.3
作者：
Pozzer, Andrea;Tsimpidi, Alexandra P.;Lelieveld, Jos
通讯作者：
Lelieveld, Jos
DOI：
10.1016/j.gloenvcha.2018.02.004
发表时间：
2018-03-01
影响因子：
8.9
作者：
Heck, Vera;Hoff, Holger;Kreft, Holger
通讯作者：
Kreft, Holger