[1][2] It was established by Maurice Strong, its first director, after the United Nations Conference on the Human Environment in Stockholm in June 1972.

The leadership of Canadian diplomat Maurice Strong convinced many of the developing nations' governments that they needed to prioritize this issue.

In the words of Nigerian professor Adebayo Adedeji: "Mr. Strong, through the sincerity of his advocacy, soon made it clear that all of us, irrespective of the stage of our development, have a large stake in the matter.

[12] Headquarters were established in Nairobi, Kenya, with a staff of 300, including 100 professionals in a variety of fields, and with a five-year fund of more than US$100 million.

The position was then held for 17 years (1975–1992) by Mostafa Kamal Tolba, who was instrumental in bringing environmental considerations to the forefront of global thinking and action.

Under his leadership, UN Environment's most widely acclaimed success—the historic 1987 agreement to protect the ozone layer—the Montreal Protocol was negotiated.

[33] Success in India's solar programme has led to similar projects in other parts of the developing world, including Tunisia, Morocco, Indonesia and Mexico.

In 2001, UNEP alerted about the destruction of the Marshlands when it released satellite images showing that 90 percent of the marsh had been lost.

[36] Climate change In 1989, UNEP published a statement predicting that "entire nations could be wiped off the face of the Earth by sea level rise if the global warming trend is not reversed by the year 2000".

[37][38] In 2005, UNEP issued a joint statement with the United Nations University predicting that "50 million people could become environmental refugees by 2010, fleeing the effects of climate change".

At this international conference 250 politicians and representatives of non-government organizations discussed future road transportation under the motto of "Sustainable Mobility–the Post-2012 CO2 Agenda".

[44] Launched in 2017, the initiative's goal is to encourage and collaborate with faith-based organizations to protect the environment and invest in green resources.

"[47] The book serves as an educational resource for students, teachers, and leaders across the world and highlights the role that faith-based organizations can play in addressing critical environmental issues.

Following the 2007 publication of the Intergovernmental Panel on Climate Change Fourth Assessment Report, the Paris Call for Action, presented by French president Jacques Chirac and supported by 46 countries, called for the UNEP to be replaced by a new and more powerful "United Nations Environment Organization", to be modeled on the World Health Organization.

[61] In December 2012, following the Rio+20 Summit, a decision by the General Assembly of the United Nations to "strengthen and upgrade" the UNEP and establish universal membership of its governing body was confirmed.

REPP was established with a five-year goal of improving energy access for at least two million people in Sub-Saharan Africa.

[64][65] In September 2018, a series of allegations were made against the executive director of the UNEP, Eric Solheim, at that time, including excessive number of days spent outside the headquarters in Nairobi, Kenya.

Several donor countries withdrew their donation in the aftermath of the allegation, including the Dutch government who announced it would withhold $8 million in funding to UNEP until nepotism issues were resolved.