A Norwegian billionaire Kjell Inge Roekke has promised to give a large percentage of his money away.
Roekke, a former fisherman who made his fortune in the oil industry, will begin by funding a research ship that will remove plastic from the ocean.
It will operate in partnership with the environmental organisation World Wide Fund for Nature.
He joins other billionaire philanthropists including Bill Gates, Warren Buffet and Mark Zuckerberg.
Mr Roekke has an estimated wealth of US$2 billion.
The research vessel will have a crew of 30, with space for up to 60 scientific staff and some laboratories and it will remove from the water and melt up to five tonnes of plastic a day.