Last fall, in order to reduce greenhouse gas emissions from passenger cars and light trucks, Colorado joined twelve other states in choosing to adopt California’s Low Emission Vehicle standards, rather than follow the corresponding federal standards, which the Environmental Protection Agency (EPA) presently is seeking to roll back. On March 11, 2019, an industry trade group filed a lawsuit seeking to invalidate Colorado’s choice. Kaplan Kirsch & Rockwell represented the Environmental Defense Fund, Natural Resources Defense Council, and the Sierra Club during the rulemaking process and will continue to represent those groups as intervenors in the litigation to defend Colorado’s authority to adopt clean car rules that protect our environment and address climate change.