British tycoon Sir Richard Branson has announced a $25 million (€19 million) prize for the first scientist to come up with a way to extract greenhouse gases from the atmosphere.
The Virgin Group chairman was joined by former US Vice President Al Gore and other leading environmentalists as he announced the challenge.
Mr Branson compared it to the competition launched in 1675 to devise a method of estimating longitude accurately. It was 60 years before English clock maker John Harrison discovered an accurate method and received his prize from King George III.
"The Earth cannot wait 60 years. We need everybody capable of discovering an answer to put their minds to it today," Mr Branson said.
Mr Gore said the planet had a "fever" that had to be taken seriously.
"Up until now, what has not been asked seriously on a systematic basis is, is there some way that some of that extra carbon dioxide may be scavenged effectively out of the atmosphere? And no one knows the answer to that," Mr Gore said.
In September, Mr Branson pledged to invest $3 billion to fight global warming, saying he would commit all profits from his travel firms - including Virgin Atlantic airline and Virgin Trains - over the next 10 years.
As part of that pledge, he launched a new Virgin Fuels business, which is to invest up to $400 million in green energy projects in the next three years.
Environmentalists have welcomed today's announcement but have warned against depending solely on competitions to solve the problem of climate change.
Green Party environment spokesman Ciarán Cuffe warned "This competition should not distract people from the immediate need to reduce emissions, both in Ireland and globally. We must look at this as one aspect of tackling climate change, rather than as a possible cure-all solution.
"It is of the utmost important that governments, individuals and the private sector play their part in the emissions challenge. This means promoting cleaner fuels and renewable energy, investing in clean, efficient transports solutions and improving the energy efficiency of the buildings we live and work in," he said.
Additional reporting AP