Although the United States has not yet passed national legislation to reduce greenhouse gas emissions, there have been other important legal developments. The federal courts have directed the government to take action regarding climate change under existing laws, and state governments have made aggressive efforts to limit emissions. The federal government has begun to plan for adapting to climate change, and it has returned to the international bargaining table in order to play a constructive role in climate negotiations. Although the lack of national legislation is unfortunate, the American system of separation of powers allows other legal action to be taken despite the paralysis in Congress.
In comparison to Europe, the United States has been a notorious laggard in the area of climate change. The US never ratified the Kyoto Protocol. For most of the first decade of this century, the White House was occupied by George W Bush, a fervent opponent of action to limit greenhouse gas emissions. Even when the White House changed hands, the situation remained frustrating because of the inability of the new administration to pass climate change legislation through Congress. Nevertheless, it would be a mistake to assume that U.S law has ignored the issue of climate change. The American constitutional system diffuses power between Congress, the executive branch, the federal courts, and state government. When one or more of those institutions fails to act, others may step in to fill the breach. That is exactly what has happened with climate change. Due to the vigorous efforts of federal courts and of many state governments, important and constructive steps have been taken to address climate change.
The first part of this article discusses the activities of the federal courts concerning climate change and shows how they have pressed the federal executive branch to take action. The second part of the article discusses the role that state governments have played in creating climate policy. That section also introduces some of the constitutional issues regarding federalism that may restrict state regulation. Finally, the article discusses the evolving U.S. efforts climate change adaptation plans, and the evolving US role in international, climate negotiations, particularly in relation to China. Because the US. and China are the two largest emitters, it is crucial to understand the differences between their positions.