In 1992 the Earth Summit in Rio de Janeiro joined together ideals of environmental movements with realities of politics in discussing five major headings of global concern: climate change, biological diversity, deforestation, Agenda 21 and Earth Charter. The summit underscored the diverse environmental interests of developed and developing countries. Though US organizations are often the most visible in world conferences, hundreds of governmental and non-governmental organizations (NGOs) concerned with the environment have been established in other countries. However, many criticized the summit as little more than a global, political attempt to risk-control and manage environmental challenges through science and technology without consideration of cultural and ecological consequences.

Critics of early environmentalism noted that issues generally concerned middle-aged people from upper-income levels who were mainly interested in the preservation and management of wilderness for future generations. Both the focus of environmentalism and the age group concerned shifted in the 1970s as young people, influenced by antiwar movements and the counterculture of the time, began to recognize that environmental degradation threatened the future of life on Earth. Nonetheless, there were still strong stratifications of the movement with voices of the poor and of minorities notably missing.

The current wave of environmental activities in the US can be traced to the 1960s and early 1970s when people like Murray Bookchin (Our Synthetic Environment, 1962) and Rachel Carson (Silent Spring, 1962) began to question the rapid advancement of technological innovation without social and environmental constraint. In 1970 Americans celebrated the first Earth Day, focusing attention on human interactions with the Earth and laying groundwork for groups such as the Environmental Defense Fund and the Natural Resources Defense Council. Additionally roots of the National Environmental Policy Act (1970) (creating the Environmental Protection Agency), Clean Air Act (1970), Clean Water Act (1972), Ocean Dumping Act (1972), Endangered Species Act (1973) and Safe Drinking Waters Act (1974) grew from this early interest. In 1978 Love Canal (Niagara Falls, New York) refocused national attention on the detrimental effects of hazardous waste on humans and their environment. Divergences also grew within environmentalists: The term “deep ecology” was coined by Naess in 1973 to champion self-realization and biocentric equality in contrast to the utilitarian treatment of nature by Western society This has underpinned radical action in environmental protests as well.

Agriculture in the US and worldwide became a focus for modern environmentalism with soil erosion, aquifer depletions, desertification, saline incursion into irrigated soils, climate change from land clearing, deforestation, resistance of pests to pesticides and loss of genetic diversity in food crops as problems with global implications. Despite the Green Revolution, importing high-yield agricultural techniques to developing countries to increase food production, concerns grew about population growth and what constitutes “sustainable development.” The notion that too many humans exist to allow coexistence with the rest of nature continued as deep ecologists suggested population reduction and a return to simpler ways of life. Early solutions for population control included zero population growth, the notion that reproduction should be for replacement or reduction in numbers only.

The 1980s brought more attention to the environment as implications of acid rain and heat pollution were recognized worldwide. Urban heat islands, created from high concentrations of concrete, human beings and combustion products from transportation, were identified as major contributors to build-ups of pollutants, especially particulates, around American cities and suburbs. Issues of urban pollution mobilized the Environmental Justice Movement to emerge from the shadows of mainstream environmentalism. It focused on racism and exposure to environmental hazards, noting the general lack of attention by mainstream, predominantly white, environmental organizations to problems concerning people of color. Out of this split grew the People of Color Environmental Leadership Summit in 1991 and many neighborhood projects, from Los Angeles, CA to the Northeast.

The 1980s and 1990s saw a strong backlash against environmentalism with environmental burdens placed on businesses and governments over-whelming available resources. The so-called “unholy trinity” of risk assessment, unfunded mandates and property rights emerged through the 1990s to threaten progress in environmental legislation. When the Exxon Valdez ran aground and dumped its oily cargo into one of the most pristine marine areas of the United States, there was a flurry of environmental activity from cleaning wildlife and shorelines to changing regulations for shipping such substances (see oil spills). However, as pictures of oil-soaked birds and marine mammals yielded to reports of cleanup fraud and environmental infighting, the event’s impact evaporated. During the early 1990s, many environmental organizations showed dramatic decreases in membership and financial support, perhaps as legislation intruded further into the lifestyles of the middle class. However, during this same time period there was an increased interest in ideas of ecofeminism (a term coined by Francoise D’Eaubonne in 1974) as a part of the environmentalist movement, connecting the domination of women and the domination of nature as scientific and political issues.

Free-market environmentalism emerged as a part of the backlash from earlier intensive centralized regulation of environmental concerns. These environmentalists suggest that decentralized tools such as market-value user fees, environmentally responsible incentives (such as rewards for recycling and waste reduction) and free markets will solve more environmental challenges than increased regulation and governmental control.

However, many critics of such ideas point to the lack of development of environmental economics to incorporate valuation of things such as scenic beauty in contrast with shoreline development. Further, questions of how to privatize management of assets such as coral reefs and migratory herds on a broad scale have received little attention. Testing of free-market environmental ideas in real situations has been conducted on a limited basis with some success, although strong concerns about the broader applications of such an approach to environmental problems remain.