Branson and Gore Launch $25m Climate Change Competition
The Earth Challenge Prize will offer $25m (£12.5m) to the person who comes up with the best way of removing significant amounts of carbon dioxide from the atmosphere, while a panel of judges will oversee the prize, including James Lovelock and Nasa scientist James Hansen.
Sir Richard said humankind must realise the scale of the crisis it faced.
"The Earth cannot wait 60 years," he said at the news conference. "I want a future for my children and my children's children. The clock is ticking."
He said if the planet was to survive, it was vital to find a way of getting rid of the greenhouse gas carbon dioxide.
Overseeing the innovations are James Hansen, the noted climate scientist and head of the Nasa Institute for Space Studies; the inventor of Gaia theory James Lovelock; UK environmentalist Sir Crispin Tickell; and Australian mammalogist and palaeontologist Tim Flannery.
They are looking for a method that will remove at least one billion tonnes of carbon per year from the atmosphere.
Al Gore, the former presidential candidate turned environmental campaigner, is also on the judging panel.
The man behind the hit documentary film An Inconvenient Truth said: "It's a challenge to the moral imagination of humankind to actually accept the reality of the situation we are now facing.
"We're not used to thinking of a planetary emergency, and there's nothing in our prior history as a species that equips us to imagine that we, as human beings, could actually be in the process of destroying the habitability of the planet for ourselves."