Amazon boss Jeff Bezos has pledged $10bn (£7.7bn) to help fight climate change.
The world’s richest man said the money would finance work by scientists, activists and other groups.
He said: “I want to work alongside others both to amplify known ways and to explore new ways of fighting the devastating impact of climate change.”
Writing on his Instagram account, Mr Bezos said the fund would begin distributing money this summer.
Mr Bezos has an estimated net worth of more than $130bn, so the pledge represents almost 8% of his fortune.
Some Amazon employees have urged him to do more to fight climate change. There have been walkouts and some staff have spoken publicly. Also, Mr Bezos is financing the Blue Origin space programme, criticised for its carbon footprint.
Compared to some multi-billionaires, Mr Bezos had done only limited philanthropy. His biggest donation before Monday’s pledge is thought to have been $2bn in September 2018 to help homeless families and fund schools.
He has also been criticised for not signing the Giving Pledge, under which the super-rich promise to give away half of their wealth during their lifetimes.
The Seattle-based company is a neighbour of Microsoft, which in January unveiled a plan to become carbon negative by 2030.