World Environment Day (WED) is celebrated on 5 June every year, and is the United Nations' principal vehicle for encouraging awareness and action for the protection of the environment. First held in 1974, it has been a flagship campaign for raising awareness on environmental issues emerging from marine pollution, human overpopulation, and global warming, to sustainable consumption and wildlife crime. World Environment Day has grown to become a global platform for public outreach, with participation from over 143 countries annually. Each year, WED has provided a new theme that major corporations, NGOs, communities, governments and all celebrities worldwide adopt to advocate environmental causes.