Pharrell Williams says he'll have all of humanity singing together at a worldwide concert June 18 to fight global warming.
The pop star is teaming up with Nobel Peace Prize-winner Al Gore and producer Kevin Wall to pull off a "Live Earth" concert on seven continents to build support for a U.N. climate pact in Paris among more than 190 nations in December.
"I think you guys know how serious the global warming thing is, and so for us we're taking it very seriously, and we wanted to do something very different this time," Williams said.
"Instead of just having people perform, we literally - and I can't go into it now because some interesting surprises are coming out soon - but we literally are going to have humanity harmonize all at once."
After giving a trademark slide show, in which he linked rising temperatures to the Arab Spring and the catastrophic Syrian war, Gore said the concert will engage "a billion voices with one message - to demand climate action now."
The U.N.-brokered climate negotiations have been simmering for years. Nations have agreed on the goal of stabilizing greenhouse gases at a level that keeps global warming below 2 degrees C (3.6 F), compared with pre-industrial times, but a legally binding agreement that puts that into action has remained elusive.
A key sticking point is how to pay for it. Another is how much historical responsibility nations must bear for polluting to industrialize versus developing countries that are polluting more now to grow their markets.
The world's two largest emitters of heat-trapping gases, China and the U.S., negotiated secretly for months in 2014 to reach a non-binding climate change agreement.
However, momentum from that deal dissipated in Lima, Peru, where a round of climate talks salvaged a compromise in December to try to set up a Paris deal.
Gore said that along with putting a price on carbon to speed up the transition to renewable energies, "we need to put a price on denial in politics. People need to stop financing denial."