<Tr> <Th> Date </Th> <Td> 5 June </Td> </Tr> <Tr> <Th> First time </Th> <Td> 5 June 1974; 43 years ago (5 June 1974) </Td> </Tr> <P> World Environment Day (WED) occurs on 5 June every year, and is the United Nation's principal vehicle for encouraging worldwide awareness and action for the protection of our environment . First held in 1973, it has been a flagship campaign for raising awareness on emerging environmental issues from marine pollution, human overpopulation, and global warming, to sustainable consumption and wildlife crime . WED has grown to become a global platform for public outreach, with participation from over 143 countries annually . Each year, WED has a new theme that major corporations, NGOs, communities, governments and celebrities worldwide adopt to advocate environmental causes . </P> <P> World Environment Day (WED) was designated by the UN General Assembly in 1972 on the first day of United Nations Conference on the Human Environment, resulting from discussions on the integration of human interactions and the environment . Two years later, in 1974 the first WED was held with the theme "Only One Earth". Even though WED celebrations have been held annually since 1974, in 1987 the idea for rotating the center of these activities through selecting different host countries began . </P>

When do we celebrate world environment day and why