Exploring river nitrogen and phosphorus loading and export to global coastal waters in the Shared Socio-economic pathways

Global Environmental Change, vol. 72, pp. 102426

Abstract

This global spatially explicit (0.5 by 0.5 degree) analysis presents the nitrogen (N) and phosphorus (P) inputs, processing and biogeochemical retention and delivery to surface waters and river export to coastal seas according to the five shared socioeconomic pathways (SSP). Four systems are considered: (i) human system; (ii) agriculture; (iii) aquaculture; (iv) nature. Exploring the changes during 1980–2015 and 2015–2050 according to the SSPs shows that the natural nutrient sources have been declining in the past decades and will continue to decline in all SSPs in future decades due to massive land transformations, while agriculture, human sewage and aquaculture are becoming increasingly dominant (globally up to 80% of nutrient delivery). More efforts than those employed in any of the SSPs are needed to slow down the global nutrient cycles. One of the drivers of the proliferation of harmful algal blooms is the tendency towards increasing N:P ratios in global freshwaters and export to the global coastal seas; this is the result of increasing N:P in inputs in food production, more efficient biogeochemical retention of P than of N in river basins, and groundwater N legacies, which seems to be most pronounced in a united world that strives after sustainability. The diverging strategies to achieve UN Sustainable Development Goals 14 (life below water), 2 (zero hunger) and 6 (clean water and sanitation) therefore require a balanced management system for both N and P in all systems, that accounts for future nutrient legacies.

Authors 9

1. Arthur H. W. Beusen

   Netherlands Environmental Assessment Agency · Utrecht University

   Affiliation as printed

   Department of Earth Sciences – Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

2. Jonathan Doelman

   Netherlands Environmental Assessment Agency

   Affiliation as printed

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

3. Rens van Beek

   Netherlands Environmental Assessment Agency · Utrecht University

   Affiliation as printed

   Department of Physical Geography, Faculty of Geosciences, Utrecht University, P.O. Box 80.115, 3508 TC Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

4. Peter J. T. M. van Puijenbroek

   Netherlands Environmental Assessment Agency

   Affiliation as printed

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

5. José Manuel Mogollón Aachen Institute of Environmental Sciences (CML)

   Leiden University · Utrecht University

   Affiliation as printed

   Department of Earth Sciences – Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA Utrecht, The Netherlands

   Institute of Environmental Sciences (CML), Leiden University, PO Box 9518, 2300 RA Leiden, The Netherlands

6. Hans J. M. van Grinsven

   Netherlands Environmental Assessment Agency

   Affiliation as printed

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

7. Elke Stehfest

   Netherlands Environmental Assessment Agency

   Affiliation as printed

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

8. Detlef Peter van Vuuren

   Netherlands Environmental Assessment Agency · Utrecht University

   Affiliation as printed

   Copernicus Institute of Sustainable Development, Faculty of Geosciences, Utrecht University, P.O. Box 80115, 3508 TC Utrecht, The Netherlands

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands

9. Lex Bouwman corresponding

   Netherlands Environmental Assessment Agency · Utrecht University · Ocean University of China

   Affiliation as printed

   Department of Earth Sciences – Geochemistry, Faculty of Geosciences, Utrecht University, P.O. Box 80021, 3508 TA Utrecht, The Netherlands

   Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key Laboratory of Marine Chemistry Theory and Technology, Ministry of Education, Ocean University of China, Qingdao 266100, PR China

   PBL Netherlands Environmental Assessment Agency, P.O. Box 30314, 2500 GH The Hague, The Netherlands