在过去的半个世纪中，环境法已经从法律的专业领域发展成为法律实践的主要内容。它已成为主流，现在影响到法律的各个方面，从行政法规到房地产，再到涉及全球问题的主要国家和国际政策。环境法也与能源法有关，能源法是其自身的重要实践领域。电力供应是美国最后一个受监管的行业，州和联邦监管机构从事价格，能源技术选择和服务条款的实质性监管。能源法涉及监​​管实践，环境和公司法实践的结合。随着18个州对电力的基本放松管制，以及华盛顿州发起的一项大规模计划，以改变为更多的可再生能源，以及为提高能效和响应能力而进行的智能电网投资，
Environmental law has evolved over the past half century from a specialty area of law to a primary element of legal practice. It has gone mainstream and now affects every aspect of law from administrative regulation to real estate to primary national and international policy on global issues. Environmental law also is related to Energy law, which is its own significant and distinct practice area. Electric power supply is the last regulated industry in the U.S., with state and federal regulatory agencies engaged in substantial regulation of price, choice of energy technologies, and terms of service. Energy law involves a combination of administrative regulatory practice, environmental, tax and corporate law practice. With fundamental deregulation of electric power in 18 states, and smart grid investment in more energy efficiency and renewable energy, the energy law field is very active and designated as a hot area of law and employment opportunities. Conventional environmental law practice includes the permitting, and enforcement, of permit emission restrictions to the air, land, and water by state and federal environmental agencies for private companies. Second, a significant aspect of environmental and energy law practice involves the setting of environmental policy, involving environmental and nongovernmental organizations, state and federal legislative committees, and private entities. There is both a domestic and international dimension to current environmental regulation. Since many pollutants have now been shown to migrate in air from California to Massachusetts, from Massachusetts to Europe, and from Japan to California, there is a cross-border and international dimension to environmental practice. The ongoing debate on global warming is one primary example of the truly international dimension of environmental challenges and policy.