The United Nations Environment Programme has set up an attractive website with a world map indicating all of the day's events, which can be found here. You can find initiatives undertaken by governments, individuals, NGOs and community groups, the private sector and youth andschool groups.
For instance, in Jalisco state, Mexico, volunteers will be cleaning streets, beaches and a lagoon.
In Antananarivo, Madagascar, the Association of Catholic Scouting will sensitize and involve girls and young women members of the association to the green economy, according to a listing on the UNEP website.
Every continent save Antarctica is participating in World Environment Day, which is held every June 5 and raises awareness on how to improve the planet's environment.
In Paris, the Organization for Economic Co-operation and Development held daylong activities, including a free breakfast for OECD staff who commute to work by bike; a documentary screening and panel discussion on waste and sustainable materials; and sessions on what the organization is doing to reduce its carbon footprint.
In Cebu City in the Philippines, residents will be planting trees and cleaning streets.
Achim Steiner, executive director of the United Nations Environment Programme, marked World Environment Day 2012 at the presidential palace in Brazil, where the Rio+20 conference on the green economy is set to start later this month.
In celebrating World Environment Day in Brazil in 2012, we are returning to the roots of contemporary sustainable development in order to forge a new path that reflects the realities but also the opportunities of a new century, Steiner said. In celebrating World Environment Day in Brazil, we recognize that in a new world the leadership and the answers to the globe's challenges are being formulated in an ever more diverse range of nations and peoples than has ever been the case in the history of humanity.