On June 1, 2017, President Donald Trump announced the United States' withdrawal from the Paris Climate Accord. Despite the shift away from addressing climate change on a federal level, the issue remains a concern at the regional, state, and local level. 

For example, on July 7, 2017, the City of New Orleans released a climate action plan with a stated goal of reducing the city's annual greenhouse gas emissions by 50 percent compared to current levels by 2030. To achieve this objective, New Orleans intends to take measures such as ending its reliance on any coal-fired power sources. Similarly, Mayor William Peduto of Pittsburgh signed a June 2, 2017, Executive Order directing the city to take various actions by 2030, including "divestment of the city's pension assets from fossil based companies." Most notably, when Governor David Ige signed SB 559 into law on June 6, 2017, Hawaii became the first state to express its commitment to the Paris Agreement through legislation. The bill obligates Hawaii to reduce greenhouse gas emissions consistent with the principles and goals of the Paris Accord. These and many other commitments are being tracked through "America's Pledge," an initiative that aims to aggregate and quantify the impact of climate change-related efforts being taken across the country.

These locally led matters also are not going unnoticed by the federal government. For instance, the Congressional Research Service ("CRS") recently issued a report titled Constitutional Limits on States' Efforts to "Uphold" the Paris Agreement. CRS concludes that to the extent that any agreements between states and foreign governments are nonbinding, they may be constitutionally permissible. CRS finds that state legislation, however, could be problematic to the extent that it "intrudes on the federal government's ability to conduct foreign relations." The test, CRS explains, is whether the "real purpose" of the state law is to respond to foreign affairs events rather than to address an area of traditional state responsibility.

Although some states and localities could potentially face legal challenges as a result of their efforts to support the Paris Agreement, pre-Paris programs are likely to persist. For instance, the Regional Greenhouse Gas Initiative ("RGGI"), a market-based program created in 2009 by nine northeast and mid-Atlantic states, is currently undergoing a program review. Following the review, RGGI's greenhouse gas emissions reduction targets may be adjusted downward for 2030, a move many are calling for in light of the reversal of certain climate change policies at the federal level.

These regional, state, and local efforts seem to signify a shift in climate change regulation away from the federal level. This may lead to a patchwork of differing requirements for regulated companies, and it could result in litigation testing the limits of non-federal climate change policy.