Live Earth concerts on Saturday meant to spur action to fight global warming must first tackle another environmental hazard -- mountains of trash and thousands of tons of greenhouse gases caused by the events.

We want to set a new global standard for dealing with waste and recycling, said John Rego, environmental adviser for the eight concerts meant to rock the world around the clock on a rolling basis from Sydney to New York and organized by an alliance led by former U.S. Vice President Al Gore.

Live Earth needs to lead by example to convince people to change their lifestyles in the long term to confront a climate crisis caused by rising emissions of greenhouse gases from burning fossil fuels, Rego told Reuters.

So all electricity to power the concerts will come from renewable sources, such as biodiesel. Greenhouse gases spewed out by stars' jets or by the audience's travel will be offset by investments in renewable energy and by safeguarding forests.

Concert props may live on long after stars such as Madonna, Shakira and Bon Jovi have left the stage -- old tires and oil drums used in the New York set will be re-used while some concert signs in Johannesburg will be used as roofing.

To cut use of plastics, burger boxes in London will be made of edible starch. Tickets to the concert in Hamburg include a 0.3 euro ($0.409) fee to absorb greenhouse gases. And in Sydney, the concert tickets allow free travel on public transport.

The goal of Live Earth is to have millions of people committing to make a few small changes in their lives and demanding change from governments and businesses, Rego said.

MILLION PEOPLE

Brazilian authorities, however, said on Wednesday they had obtained a court injunction suspending the Live Earth show in Rio de Janeiro on concerns about security in the crime-hit city.

Any cancellation of the free-admission concert on Copacabana beach would spare organizers having to clean up after a likely crowd of a million people. The decision can be appealed.

The other seven host cities are Tokyo and Shanghai along with Sydney, Johannesburg, Hamburg, London and New York.

U.N. studies this year forecast ever more droughts, heatwaves, easier spread of disease, floods and rising seas from global warming. Big events, ranging from U.N. conferences to rock concerts, have been trying to get greener.

In 2003, for instance, the Rolling Stones added a greenhouse gas clean-up fee to concert tickets to show, as they said, that rock and roll is not a gas. Soccer's World Cup and the Super Bowl in the United States have also tried to offset emissions.

But many fall short -- a U.N. Earth Summit in Johannesburg in 2002 only offset a fraction of emissions in a voluntary plan.

Even Live Earth is sometimes cautious. Its green guidelines say, for instance, that staff ground travel will be by hybrid or high efficiency vehicles where possible.

At typical concerts, more than half the greenhouse gases are emitted by thousands of people traveling to the venues by bus, train, subway or car. Those totals can only be estimated.

It's a dilemma for Live Earth -- they have to create carbon to save carbon, said Michael Buick, spokesman of Climate Care which helps invest in clean energy to offset greenhouse gases.

Rego said each of the Live Earth concerts aimed to produce about a quarter less greenhouse gases than the 3,000-4,000 metric tons pumped out by comparable concerts in the past.

Four thousand metric tons is roughly equivalent of annual emissions by 200 people in the United States or 800 in China.