World Environment Day is a day that is supposed to stimulate awareness of the environment and enhance political attention and public action. The official day is June 5. This was the day that the United Nations Conference on the Human Environment began. The first World Environment Day was on 1973. The theme this year is Forests-Nature At Your Service. Forests cover one third of the earth’s land mass, performing vital functions and services around the world which make our planet alive with possibilities. In fact, 1.6 billion people depend on forests for their livelihoods. They play a key role in the world ecology, releasing oxygen into the atmosphere while storing carbon dioxide. Thousands of activities are typically organized worldwide, with beach clean-ups, concerts, exhibits, film festivals, community events and much more. Each year there is a different host city. For 2011 it is New Delhi, India.