Policy Update

Increased Nutrient Runoff Risk as a Result of Climate Change


Mississippi River

NCEL Point of Contact

Chris Askew-Merwin
Sustainable Agriculture and Water Specialist


A recent study published in Science has found that excessive nutrient enrichment is likely to increase in the continental United States, due to changes in weather patterns as a result of climate change. This climate change induced precipitation could boost nitrogen runoff by as much as 20% over the next century. These reduced levels of oxygen create conditions for ‘dead zones’ which have been experienced every year since 1950 with increasingly severe effects.

The resulting hypoxia would be damaging for all watersheds, but particularly so for the Upper Mississippi Atchafalaya River Basin, the Northeast and the Great Lakes basin as these areas are already suffering under a high nutrient load due to increasing use of nitrogen-based fertilizers, with the greater levels of pollution leading to an accumulation effect. When these results are extrapolated on a global level, it could lead to famine, especially in Southeast Asia with its large population and dependence on surface water for sustenance.


  • The full study is available here.
  • A news story on the study is available here.