After a one-year hiatus, hundreds of the world's most powerful people in tech, media and markets once again made a pilgrimage to Sun Valley, Idaho, to attend an exclusive conference organized by the investment bank Allen & Company.
With many of his fellow captains of industry, entertainment and technology having flown in by private jet, Gates stressed the importance of the problem.
Gates has in the past defended his use of private jets, insisting he took steps to mitigate their damage.
While promoting his book How to Avoid a Climate Disaster in February, Gates stated: 'I am offsetting my carbon emissions by buying clean aviation fuel and funding carbon capture and funding low cost housing projects to use electricity instead of natural gas and so I have been able to eliminate it and it was amazing to me how expensive that was, that cost to be green... we've got to drive that down.'
On Wednesday the conference kicked off with a presentation on e-commerce by Shopify by CEO Tobias Lutke, and a general discussion of the global economic climate.
A session on criminal justice reform was also on the agenda, as was immigration reform.
On Thursday, Allen & Co. regulars Barry Diller and his wife, fashion designer Diane von Furstenberg, held a session on creativity.
Diller - a Hollywood icon who was the former CEO of both Paramount and what was 20th Century Fox, which is now part of Disney - declared streaming services killed the film industry.
'The movie business is over,' proclaimed Diller, 79, in an exclusive interview with NPR on the sidelines of the conference on Friday.
'The movie business as it was before is finished and will never come back.
'The definition of movie is in such transition it doesn't mean anything anymore.'
Movie-making has become less of an art form and more of a factory-like production pushing quantity over quality to supplement other services, Diller said.
From the world of finance, Mala Gaonkar, co portfolio-manager of Lone Pine Capital, was seen with heavily-noted papers; Ted Weschler, investment manager at Berkshire Hathaway was spotted talking to Meg Lawler, director of the annual event; while Mike Speiser, a managing partner at venture capital firm Sutter Hill Ventures, was also in attendance.
Israeli-American venture capitalist Vivi Nero was spotted on Friday, as was Gates' money manager, Michael Larson. David Velez, CEO of Nubank, was also in attendance.
Richard Reeves, a British economist at the Brookings Institute, was also present, as was David Weinberg, chairman of the Coca-Cola Company.
In healthcare, Amy Vogel, of blood purification company CytoSorbents Corporation, was seen on Friday, as was Erica Hauver, an expert on Keto Nutrition Therapy and chronic disease reversal.