The United Nations Environment Programme (UNEP) is an international institution (a programme, rather than an agency of the UN) that coordinates United Nations environmental activities, assisting developing countries in implementing environmentally sound policies and practices. It has its headquarters at Nairobi, Kenya.

Oceans absorb approximately 1/3 of CO₂ produced by humans, which has detrimental effects on marine environment. The increasing level of CO₂ in oceans changes the seawater chemistry by decreasing the level of pH. This process is also known as acidification.

2011 was the International Year for Forests. 2007 was the International Year of Dolphins. 2010 was the International Year of Biodiversity.

Stockholm Convention on Persistent Organic Pollutants is an international environmental treaty, signed in 2001 and effective from May 2004, that aims to eliminate or restrict the production and use of persistent organic pollutants (POPs).

The Melbourne Principles for Sustainable Cities are ten short statements on how cities can become more sustainable. They were developed in Melbourne (Australia) on 2^nd April 2002 during an international Charrette, sponsored by the United Nations Environment Programme (UNEP) and the International Council for Local Environmental Initiatives.

All the mentioned three conventions were adopted as the result of discussions at the 1992 Earth Summit at Rio De Janeiro.

Wangari Muta Maathai (1^st April, 1940 - 25^th September, 2011) was a Kenyan environmental and political activist. In the 1970s, Maathai founded the Green Belt Movement, an environmental non-governmental organisation focused on the planting of trees, environmental conservation and women's rights. In 1986, she was awarded the Right Livelihood Award, and in 2004, she became the first African woman to receive the Nobel Peace Prize for her contribution to sustainable development, democracy and peace.

Ex-situ conservation means literally, off-site conservation. It is the process of protecting an endangered species of plant or animal outside its natural habitat; for example, by removing part of the population from a threatened habitat and placing it in a new location, which may be a wild area or within the care of humans.

The Global Strategy for Plant Conservation (GSPC) is a program of the UN's Convention on Biological Diversity. The GSPC sought to slow the pace of plant extinction around the world by 2010. The GSPC began as a grass-roots movement in 1999 with discussions at the 16^th International Botanical Congress in St. Louis. A group of specialists subsequently met in Gran Canaria and issued the Gran Canaria Declaration Calling for a Global Plant Conservation Strategy.

The North American Model of Wildlife Conservation is considered to be one the most successful conservation models in world. It has its origins in 19th century conservation movements, the near extinction of several species of wildlife (including the American Bison) and the rise of sportsmen with the middle class. Beginning in the 1860s sportsmen began to organise and advocate for the preservation of wilderness areas and wildlife.

The Intergovernmental Panel on Climate Change (IPCC) is a scientific intergovernmental body, set up at the request of member governments. It was first established in 1988 by two United Nations organisations, the World Meteorological Organisation (WMO) and the United Nations Environment Programme (UNEP), and later endorsed by the United Nations General Assembly through Resolution 43/53.

The Nagoya Protocol on Access to Genetic Resources and the Fair and Equitable Sharing of Benefits Arising from their Utilization (ABS) to the Convention on Biological Diversity is a supplementary agreement to the Convention on Biological Diversity. It provides a transparent legal framework for the effective implementation of one of the three objectives of the CBD: the fair and equitable sharing of benefits arising out of the utilization of genetic resources. The Cartagena Protocol on Biosafety is an international agreement on biosafety, as a supplement to the Convention on Biological Diversity. The Biosafety Protocol seeks to protect biological diversity from the potential risks posed by genetically modified organisms resulting from modern biotechnology.

GEF is the largest public fund provider for projects to improve the global environment. An independently operating financial organization, the GEF provides grants for projects related to biodiversity, climate change, international waters, land degradation, the ozone layer, and persistent organic pollutants.

On March 15, 2011, a record ozone layer loss was observed, with about half of the ozone present over the Arctic having been destroyed. In 2006, a 2.5 million square kilometer ozone hole was detected over Tibet. Again in 2011 a ozone hole appeared over mountainous regions of Tibet, Xinjiang, Qinghai and the Hindu Kush. The discovery of the Antarctic ozone hole by British Antarctic Survey scientists Farman, Gardiner and Shanklin was announced in a paper in Nature as early as in May 1985.

Minamata disease was first discovered in Minamata city in Kumamoto prefecture, Japan, in 1956. It was caused by the release of methylmercury in the industrial wastewater from the Chisso Corporation's chemical factory, which continued from 1932 to 1968. This highly toxic chemical bioaccumulated in shellfish and fish in Minamata Bay and the Shiranui Sea, which when eaten by the local populace resulted in mercury poisoning.