World Environment Day (WED) is celebrated annually on 5 June and encourages awareness and action for the protection of the environment. It is supported by many non-governmental organizations, businesses, government entities, and represents the primary United Nations outreach day supporting the environment. . First held in 1974, it has been a platform for raising awareness on environmental issues as marine pollution, overpopulation, global warming, sustainable development and wildlife crime.
https://en.wikipedia.org/wiki/World_Environment_Day