Elon Musk is putting up $100 million as part of a new X Prize Foundation competition focused on carbon removal technology. The contest, announced Monday morning, will run for four years and is open to teams around the globe.

Axar.az reports citing foreign media that fifteen teams will be selected for the competition within 18 months. They will each get $1 million, and 25 separate $200,000 scholarships will be given to student teams who enter. The grand prize winner will be awarded $50 million, second place will receive $20 million, and third place will get $10 million.

Winners will have to “demonstrate a solution that can pull carbon dioxide directly from the atmosphere or oceans and lock it away permanently in an environmentally benign way,” according to the X Prize Foundation. Judges will be looking for solutions that could remove one ton of CO2 per day that can scale to gigaton levels. Full competition guidelines will be published on April 22nd.

“We want to make a truly meaningful impact. Carbon negativity, not neutrality,” Musk says in a statement. “This is not a theoretical competition; we want teams that will build real systems that can make a measurable impact and scale to a gigaton level. Whatever it takes. Time is of the essence.”