A huge number of private companies are going to invest trillions of euros in limiting global warming.
Hundreds of firms - which control 40% of the world's money - have agreed.
In his closing remarks, The US President also criticised China and Russia for not attending the Cop26 climate conference.
Meanwhile Bill Gates says he "doubts" the target to limit global warming to 1.5 degrees celsius can be met, warning it "will be very difficult".
Speaking at the summit in Glasgow, the billionaire philanthropist stressed the need to drive down the cost of green technology to make it affordable for everyone:
"Together we must drive a green innovation revolution, one that stops climate change, protects vulnerable communities, and continues the world on a path to progress."
