In a changing climate, cities worsen water quality

摘要

A study published in ES&T (DOI 10.1021/es800264f) finds that urban areas become a bigger source of nitrogen pollution to water when rainfall patterns are more variable. This concerns scientists who are struggling to clean up water, because global warming is expected to cause exactly the kind of weather extremes that could make the problem worse: dry spells followed by intense rain. In 2003, the Chesapeake Bay saw both high rainfall and record-setting hypoxia (low-oxygen conditions linked to excess nitrogen that create lifeless dead zones), says biogeochemist and study coauthor Sujay Kaushal of the University of Maryland Center for Environmental Science (UMC-ES).