Billionaire philanthropist Bill Gates defended owning a private jet while warning about the dangers of failing to reduce carbon emissions.

The Microsoft co-founder said during an interview with Fox News host Chris Wallace on Sunday that the world needed to bring the amount of emissions from the current amount of 51 billion tons to zero in the next 30 years or there will be severe consequences.

Gates was on the television show to promote his new book, How to Avoid a Climate Disaster, and was asked about a passage that states he is an “imperfect messenger” because he lives in large houses and is known to use private jets.

“How do you answer people who say ‘well, who is Bill Gates to preach to us?” Wallace questioned, to which Gates appeared to suggest the stance was “absolutely right” but noted he takes steps to make up for his personal carbon footprint via his work.

Gates elaborated: “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.”

He continued: “I felt like, if we have this idealistic generation and this wonderful goal, we need a plan, and that my experience could help contribute to that plan.”

In January this year, The Guardian reported Cascade Investment, a fund that oversees Gates’ wealth, was in a “£3bn bidding war” ($4.2bn) after teaming up with private equity firm Blackstone to buy private jet services company British firm Signature Aviation.

In 2014, Gates said in a Q&A session on messageboard website Reddit he considered a private jet to be one of his more expensive “guilty pleasure” purchases.

He said: “Owning a plane is a guilty pleasure. Warren Buffett called his the Indefensible. I do get to a lot of places for Foundation work I wouldn’t be able to go to without it.”

Gates was referencing the Seattle, Washington-based Bill & Melinda Gates Foundation, the vast philanthropist organization founded back in 2000 with his wife Melinda. The Bill & Melinda Gates Foundation has been contacted for comment by Newsweek.

In the Fox interview, Gates said it was “completely unrealistic” to think the world can eliminate emissions by 2030, but it is possible to reach zero net emissions by 2050. “It’s hard, we are going to have to use all 30 years, but it’s not impossible,” he said.

Without slashing net emissions in the coming decades, Gates said the world will see “10 times as much migration” as areas of the world become uninhabitable.

He added: “The temperature just keeps going up, and it is going up more rapidly than it has in natural history. But the instability overall will be five times as many deaths as the peak of the pandemic, and going up every year.

When asked about critics of climate change, he conceded it was fair for people to have different views on tactics to combat climate change and having both political parties in the conversation is important to making progress in combating its effects.

But Gates also warned: “There’s no doubt that we are putting Co2 into the atmosphere, there’s no doubt that that increases temperatures and that affects the weather.”