It's a fair question, given his lifestyle.
His interviewer Anderson Cooper asked: "Are you the right messenger on this, because you fly private planes a lot and you're creating a lot of greenhouse gasses yourself?"
Gates replied: "Yeah, I probably have one of the highest greenhouse gas footprints on the planet, my personal flying alone is gigantic.
"Now, I'm spending quite a bit to buy aviation fuel that was made with plants. You know, I switched to an electric car, I use solar panels, I'm paying a company at a very high price to pull a bit of carbon out of the air and stick it underground, so I'm offsetting my personal emissions. "
He continued: "So, it's costing like $400 (£288) a tonne, it's like $7m."
Gates was then asked: "So you're paying $7m a year to offset your carbon footprint?"
He then replied: "Yep."
That's lot of dough to be spending on offsetting emissions, but Gates has got the cash to do it, and he wants to encourage others who can afford it to do the same.
Wouldn't that be nice?
During the interview, which handily lasted 60 minutes, Gates also said that he believes it is possible to prevent a climate catastrophe.
However, he thinks we need breakthroughs in science and technology, and global participation on an unprecedented scale if we're to stand a chance.
Cooper asked: "You believe this is the toughest challenge humanity has ever faced?"
Gates responded: "Absolutely. The amount of change, new ideas. It's way greater than the pandemic. And it needs a level of cooperation that would be unprecedented."
He later added: "We have more educated people than ever.
"We have a generation that's speaking out on this topic. And, you know, I got to participate in the miracle of the personal computer and the internet.
"So, yes, I have a bias to believe innovation can do these things."
Gates also used the platform to call upon US President Joe Biden - who recently undid Donald Trump's work and re-joined the Paris Climate Accord - to lead the world on green energy and green-thinking.
Let's hope that this is another of Gates' predictions that comes true.
Featured Image Credit: PA
- Bill Gates Says He’d Choose To Marry Ex-Wife Melinda ‘All Over Again’
- Bill Gates Says He Fully Intends To Lose His Rich List Spot While Still Alive
- Billionaire once wealthier than Bill Gates explains what it was like losing $70 billion
- Bill Gates says he's done some 'weird cr*p' in his life, such as drinking 'water from fecal sludge'