The Worldwatch Institute, based in Washington DC, has issued an Earth Day report card which details some of the organisers' concerns. It says:
It will be the 30th time the organisers have made their annual attempt to bring together the planet's population to "promote a healthy environment and a peaceful, just, sustainable world".
The Millennium Dome is leading the UK's participation, with "recycled" music. Mass plantings in Chile, a mock nuclear power station evacuation in South Africa and a car-free day in Sydney, Australia, are among other events, all on the theme of "clean energy".
"Agadoo is rubbish"
The Millennium Dome, the centrepiece of the United Kingdom's celebrations of the new era, is marking Earth Day with an Eco-Festival.
This will feature "an environmental band", Weapons of Sound, playing music on instruments recycled from junk including gas pipes and shopping trolleys.
The pop group Black Lace aims to recycle old rubbish (the organisers' term) in two concerts including their hit Agadoo.
The Dome, at Greenwich in southeast London, contains a range of permanent environmental features, prompting its operators to call it "the UK's biggest recycling machine".
It is trying to reprocess or re-use as much as possible, using rainwater to flush all visitor toilets and sewage sludge to generate electricity.
Half a billion involved
Earth Day has been marked annually since 1970, and this year will involve an estimated 500 million people in every part of the world.
The Worldwatch Institute, based in Washington DC, has issued an Earth Day report card which details some of the organisers' concerns. It says:
These include the rise of citizens' groups and the growing use of micropower, small-scale renewable energy schemes.