Big name rock stars and musicians from around the globe performed at concerts on six continents to raise awareness about climate change.
A sold-out crowd rocked London's Wembley Stadium, and other concerts were held in Sydney, Tokyo, Shanghai, Hamburg, Johannesburg, Rio de Janeiro and New York.
"Wembley Stadium, this is the greatest show on the planet, and for the planet. It's Live Earth."
The London show like the shows at other venues attracted some of the biggest names in the music business, including Genesis, Red Hot Chilli Peppers, Foo Fighters, Black Eyed Peas, John Legend and Madonna, to name but a few.
They all came together to draw attention to what former US Vice President turned environmental activist Al Gore called "an SOS, a wake-up call to the entire world."
Gore, who is one of the organizers of the concerts, spoke to the London audience live via satellite from Washington. He explained the idea for the concerts, which organizers hoped would reach up to two-billion people through broadcasts on radio, television and the Internet.
"In Africa, there is a proverb that says, 'if you want to go quickly, go alone. If you want to go far, go together.' We have to go far quickly. So, today, we are gathered on all seven continents in eight giant concerts -- two billion people, we are gathered with one message."
While the shows have a lot of support, there are some who question the idea of the Live Earth concerts. The music is an obvious draw, but some people attending the concert in London also were divided about the long-term impact of the concerts.
"It's something that the world really needs to wake up to, climate change. I think we are all a bit too na�ve, and I know there has been a little bit of criticism towards today -- is it actually going to cause more harm than good?"
"There is a lot of awareness out there already. People know that there is global warming. So, a concert is not going to help us.
"It's all for a good cause. We all try to do our bit, recycling and everything else.
"It's good to think that you are actually making a difference, as well."
There are also those who believe that no matter how well intentioned the organizers of the concert are, governments need to take the lead in ensuring a reduction of carbon emissions.
Zac Goldsmith is the editor of the Ecologist magazine.
"The government can raise the bar in this, and there is a lot it can do. The government spends each year 125-billion pounds on goods and services, tax payers' money. It should be investing that money in the most sustainable goods, in the most sustainable services."
Gore says he hopes the concerts will jump-start "an unprecedented and sustained global movement" against climate change.