1970- Millions in United States gather for first Earth Day.
1972- Scientists report most acid rain in Sweden originates in other countries.
1973- Convention on International Trade in Endangered Species of Wild Fauna and Flora protects endangered species.
1973- Arab countries in OPEC announce oil embargo against United States.
1974- Chlorofluorocarbons are first hypothesized to cause ozone thinning.
1976- Dioxin (poisonous chemical) released in industrial accident at pesticide plant in Italy.
1979- Worst nuclear accident in U. S. history occurs at three Mile Island nuclear power plant in Pennsylvania.
1982- Convention on the Law of the Sea developed to protect ocean's resources.
1984- World's worst industrial accident at pesticide plant in India kills and injures thousands.
1985- Scientists discover and measure size of ozone hole over Antarctica.
1986- World's worst nuclear accident occurs at nuclear power plant in Chornobyl, Soviet Union.
1986- International Whaling Commission announces moratorium on commercial whaling.
1987- Montreal Protocol requires countries to phase out ozone-depleting chemicals.
1989- Exxon Valdez oil tanker creates largest oil spill in U.S. history.
1990- First intergovernmental Panel on Climate Change.
1991- World's worst oil spill occurs in Kuwait during war with Iraq.
1992- U.N. Conference on Environment and Development (Earth Summit) held in Brazil.
1994- International Conference on Population and Development held in Egypt.
1995- Second IPCC Assessment warns of human influence on global warming.
1997- Forest fires destroy more tropical forests than ever recored before; Indonesia is particularly hit.
1999- Human population reaches 6 billion
2000- Treaty on Persistent Organic Pollutants requires countries to phase out certain highly toxic chemicals.
2001- Third IPCC Assessment cites strong evidence humans are responsible for most of observed global warming in past 50 years.
2001- President Bush decides the U.S. will not ratify the Kyoto Protocol, which mandates the reductions in CO2 emissions to combat global warming.
2002- World Summit on Sustainable Development held in South Africa.
2002- Oil spill off Spain's coast raises awareness of ocean's vulnerability.
