Climate Change and Federal Environmental Law
Human activities, particularly the combustion of fossil fuels and the large-scale transformation of land cover, affect ecosystems around the world. Changes in temperature, precipitation, and water chemistry are altering our environment. These changes will also affect environmental regulatory frameworks, either rendering them ineffective or forcing them to adapt to achieve their goals under changing conditions.
Global temperature has increased by 0.8°C over the last century. Climate scientists estimate that we are committed to an additional 0.5°C increase due to the amount of carbon dioxide (“CO2”) that is already present in the atmosphere. Rising temperatures have been accompanied by a wide range of environmental changes, including, retreat of sea ice and glaciers, sea level rise, and changes in the intensity and frequency of storms and precipitation events. Rising CO2 concentrations has not only changed the composition of the air, but it is also changing the chemistry of the water: CO2 is absorbed by the oceans, which forms carbonic acid, causing the acidification of the oceans.
These changes mean that regulations intended to protect natural resources and promote conservation will be applied under conditions significantly different from those that prevailed when they were drafted. Achieving the original goals of these regulations will require a careful assessment of long-standing assumptions, as well as decisive action to change regulatory practices in ways that accommodate, offset, and mitigate climate change. Three such laws will be explored in this article: the Endangered Species Act (“ESA”), the Clean Water Act (“CWA”), and the Clean Air Act (“CAA”).