Some 35 million of people across the globe will take to their local parks, waterways and forests this weekend in the annual United Nations-backed Clean Up the World campaign. Starting today, volunteers in 120 countries will take part in the three-day event, held in partnership with the UN Environment Programme (UNEP).

Clean Up the World Volunteers after cleaning up a beach in Israel. [UNEP]

This year's campaign, which works at the grassroots level to mobilize communities to clean and conserve their local environments, is in support of the 2010 UN International Year of Biodiversity.

"The current state of biodiversity and the implications of its continued loss threaten human well-being and economies, North and South," said UNEP Executive Director Achim Steiner.

"By acting locally, we can work towards reducing the impacts of land-based pollution and unsustainable consumption patterns, two of the factors underlying environmental degradation and the loss of natural capital."

He pointed out that ecosystems – and the biodiversity that underpins them – generate services worth trillions of dollars, supporting livelihoods around the world.

"It is our responsibility, as custodians of the planet today, to conserve and to promote sustainable use and to hand over a healthy, functioning and productive natural world to the next generation," the UNEP chief stressed.

This weekend, volunteers will take part in activities ranging from cleaning up small villages to implementing recycling programmes and planting trees.

Boy Scouts in the Philippines will help rehabilitate a protected mangrove, while 27,000 young people across Zimbabwe will embark on a campaign against veld fires.

"Clean Up the World brings the focus squarely on people as agents of change," Mr. Steiner emphasized.