Limits to Growth, The

The Limits to Growth, written in 1972 by a team of researchers from the Massachusetts Institute of Technology (MIT), presented the results of a study in which a computer model attempted to predict the fate of society. The model studied the interrelationships between the world's population, agricultural production, natural resources, industrial production, and pollution.


Litigation, a case, controversy, or lawsuit, is a contest authorized by law, in a court of justice, for the purpose of enforcing a claimed right. Participants (plaintiffs and defendants) in lawsuits are called litigants.

Malthus, Thomas Robert English Classical Economist and Clergyman (1766–1834)

Thomas Robert Malthus is best remembered for his 1798 treatise titled An Essay on the Principle of Population as it Affects the Future Improvement of Society. Thomas Robert Malthus.

Marine Protection, Research, and Sanctuaries Act

Although officially named the Marine Protection, Research, and Sanctuaries Act of 1972, this statute is better known by its common name, the Ocean Dumping Act. An amendment known as the "Ocean Dumping Ban Act of 1988" significantly superceded certain aspects of the original act.

Mass Media

Before the 1960s, the media reported sporadically on the environment—often then referred to as the 'ecology' issue.


Mediation is a facilitated negotiation in which a skilled, impartial third party seeks to improve relations between parties to resolve a conflict by improving communication, identifying interests, and exploring possibilities for a mutually agreeable resolution. The mediator has no power to impose any solution.

Medical Waste

Medical wastes are generated as a result of patient diagnosis and/or treatment or the immunization of human beings or animals. The subset of medical waste that potentially could transmit an infectious disease is termed infectious waste.


Mercury is a metal with chemical similarities to zinc and cadmium. The metal is liquid at room temperature, with a freezing point at –31°C, and it is one of the most volatile metals.

Methane (CH4)

Methane is an invisible, odorless, and combustible gas present in trace concentrations in the atmosphere. It is the major component of natural gas, a Chemical structure of methane (CH4).

Mexican Secretariat for Natural Resources

The Mexican Secretariat for Natural Resources (La Secretaría del Medio Ambiente y Recursos Naturales or SEMARNAT) is the government office in Mexico responsible for creating sound national environmental policy, reversing existing damage to the environment, and establishing programs for sustainable development. SEMARNAT oversees the management of natural resources and coordinates development with other agencies.


Modern mining is an industry that involves the exploration for and removal of minerals from the earth, economically and with minimum damage to the environment. Mining is important because minerals are major sources of energy as well as materials such as fertilizers and steel.

Mining Law of 1872

The General Mining Law of 1872 was enacted to promote the exploration and development of domestic mineral resources, primarily in the West. The law permits U.S.

Mixing Zone

A mixing zone is an area of a lake or river where pollutants from a point source discharge are mixed, usually by natural means, with cleaner water. In the mixing zone, the level of toxic pollutants is allowed to be higher than the acceptable concentration for the general water body.

Mold Pollution

Mold pollution is the growth of molds in a building resulting in damage to or the destruction of the structure itself (or its contents) and adverse health effects on the building's occupants. It is estimated that about 10 percent of U.S.

Montréal Protocol

Following the discovery of the Antarctic ozone hole in late 1985, various governments recognized the need for stronger measures to reduce the production and consumption of a number of chlorofluorocarbons (CFCs). CFCs, which are human-made chemicals widely used in manufacturing, have been found to deplete the ozone layer that shields the surface of Earth from harmful forms of solar radiation.

Nader, Ralph American Consumer Advocate and Environmentalist (1934–)

When a young Ralph Nader wrote a book about automobile safety, it made him a household name across America. The experience sparked a lifetime of service to numerous safety, political, and environmental causes.

NAFTA (North American Free Trade Agreement)

On December 17, 1992, Canada, Mexico, and the United States entered into a historical trade pact called the North American Free Trade Agreement (NAFTA). It aims to increase trade by expanding market access and reducing investment barriers across North American borders.

National Environmental Policy Act (NEPA)

When signed into law in 1970, the National Environmental Policy Act (NEPA) was a visionary and wide-reaching statute that required U.S. agencies to fully identify, analyze, and weigh the environmental impacts of their decisions.

National Oceanic and Atmospheric Administration (NOAA)

Established in 1970 under the Department of Commerce, the National Oceanographic and Atmospheric Administration (NOAA) guides the United States' use and protection of its air and water resources. With respect to air resources, the agency conducts research and gathers data about the earth's air, and engages in subsequent technical analyses.

National Park Service

Established in 1916 under the National Park Service Organic Act, the National Park Service (NPS) manages over 83.6 millions acres of federal parks, including battlefields, cemeteries, historical sites, lakeshores, memorials, monuments, parkways, preserves, recreation areas, rivers, seashores, and trails. The NPS is supervised by both a director and the assistant secretary for fish and wildlife and parks, and serves as a Department of the Interior bureau funded by Congress.

National Pollutant Discharge Elimination System (NPDES)

Under the Clean Water Act, the National Pollutant Discharge Elimination System (NPDES) helps control the discharge of pollutants into water bodies by regulating point sources. By definition, point sources are discrete conveyances such as man-made ditches, tunnels, channels, or pipes that directly discharge into surface waters.

National Toxics Campaign

The National Toxics Campaign (NTC) was once a leading environmental organization, dedicated to helping local communities seek environmental justice. From its inception in the 1980s until it ended in 1993, this grassroots organization helped many citizen groups develop strategies to hold industry and government accountable for damages to human health and the environment.