June 5, 2004
World Environment Day was established by the United Nations General Assembly in 1972 to mark the opening of the Stockholm Conference on the Human Environment. Another resolution, adopted by the General Assembly the same day, led to the creation of UNEP（联合国环境规划署United Nations Environment Programme）.
World Environment Day can be celebrated in many ways, including street rallies, bicycles parades, green concerts, essay and poster competitions in schools, tree planting, recycling efforts, clean-up campaigns and much more.
Heads of State, Prime Ministers and Ministers of Environment deliver statements and commit themselves to care for the Earth. More serious pledges are made which lead to the establishment of permanent governmental structures dealing with environmental management and economic planning. This observance also provides an opportunity to sign or ratify international environmental conventions.
World Environment Day, commemorated each year on 5 June is one of the principal vehicles through which the United Nations stimulates worldwide awareness of the environment and enhances political attention and action.
The World Environment Day theme selected for 2004 is Wanted! Seas and Oceans - Dead or Alive? The theme asks that we make a choice as to how we want to treat the Earth's seas and oceans. It also calls on each and every one of us to act. Do we want to keep seas and oceans healthy and alive or polluted and dead?
The main international celebrations of the World Environment Day 2004 will be held in Barcelona, Spain in close collaboration with the Universal Forum of Cultures. UNEP is honoured that the City of Barcelona, the Catalan Regional Government and the Government of Spain will be hosting this important United Nations day. (来源：http://www.EnglishCN.com)

                                               Previous Themes
2003 Water - Two Billion People are Dying for It! 水－20亿人生命之所系！
2002 Give Earth a Chance 使地球充满生机！
2001 Connect with the World Wide Web of Life 用全球网络联接世界万物！
2000 The Environment Millennium - Time to Act 环境新纪元，时候已到，行动起来！
1999 Our Earth - Our Future - Just Save It! 拯救地球就是拯救未来！
1998 For Life on Earth - Save Our Seas 为了地球上的生命，拯救我们的海洋
1997 For Life on Earth  为了地球上的生命
1996 Our Earth, Our Habitat, Our Home 我们的地球、我们的生境、我们的家园
1995 We the Peoples: United for the Global Environment 我们世界各族人民：为保护全球环境而携手努力！
1994 One Earth One Family  我们的地球－我们的家园
1993 Poverty and the Environment - Breaking the Vicious Circle 贫困与环境－打破这一恶性循环
1992 Only One Earth, Care and Share 只有一个地球－让我们关爱和分享它
1991 Climate Change. Need for Global Partnership  需要为应付气候变化而建立全球伙伴关系
1990 Children and the Environment 儿童与环境