A Fox News review of flight data and an industry emissions calculator found that the jet emitted an estimated 138 metric tons of carbon on trips dating from Jan. 10 to Aug. 6.
The numbers come as Kerry, President Biden's climate envoy, emphasizes the need for climate action amid the United Nation's latest report.
"Today's report from the @IPCC_CH shows that we cannot afford further delay," he tweeted. "The science has been certain for decades, but the latest report makes it abundantly clear – the climate crisis is not only here, it is growing increasingly severe."
Fox News reported last week that Kerry's family jet took at least 16 flights in 2021. With additional data, those numbers have been updated to include two flights on Aug. 6 and one on Jan. 10. Fox News previously excluded another flight because it was recorded as only 10 minutes long and had the same departure and destination location.
In total, Kerry's private jet has taken at least 20 trips this year (including the brief 10 min. flight) with 1597 combined minutes, or more than 26 hours. Many of these flights occurred within Massachusetts, including Martha's Vineyard and Boston International Airport. At least two flights took place between Massachusetts and New Jersey.
Based on Paramount Business Jets' emissions calculator, the Kerry family jet's carbon emissions would have reached an estimated 303,309 lbs. or 138 metric tons.
For comparison, the Environmental Protection Agency (EPA) says that the average passenger vehicle emits 4.6 metric tons of carbon dioxide in a given year. It's unclear how much more the Kerry family jet will fly this year but so far, it has racked up 30 times more than the annual amount for the average passenger vehicle.
"John Kerry’s climate hypocrisy is writ large," said Steve Milloy, a former member of President Trump's transition team and founder of JunkScience.com
In a statement to Fox News, he added that "[i]f climate is such an immediate and existential crisis, how does [Kerry] dare own a home on the island of Martha’s Vineyard? The only question about all this is the flavor of Kerry’s hypocrisy – elitist, cynical or both?"
"Elitist Kerry has justified his massive carbon footprint by saying that he is an important guy and must jet everywhere to save the planet. On the other hand, cynical Kerry has admitted that even if the world cut emissions to zero, that would not solve the ‘climate problem’ … Sure, Kerry makes a good poster child for climate hypocrisy, but he is not alone. Al Gore, Arnold Schwarzenegger, Leonardo DiCaprio, Barack Obama are some other mega-carbon footprint-making climate alarmists that come to mind. Having learned nothing from Marie Antoinette, these climate hypocrites sabotage their own efforts."
The news comes as Biden advances a plan to "make half of all new vehicles sold in 2030 zero-emissions vehicles, including battery electric, plug-in hybrid electric, or fuel cell electric vehicles."
Earlier this year, footage surfaced in which Kerry defended flying via private jet to receive an environmental award in Iceland in 2019. He called flying private "the only choice for somebody like me who is traveling the world to win this battle."
Since those reports, Kerry has remained relatively quiet about criticism that his family's travel habits are hypocritical. When Kerry appeared before Congress in May, he told a House committee that he needed to leave at a certain point as he was flying commercial.
A State Department spokesperson for Kerry told Fox News: "Secretary Kerry travels commercially or via military air in his role as Special Presidential Envoy for Climate." The spokesperson later clarified to Fox News that Kerry himself wasn't on any of the flights noted for this year. They did not respond to an inquiry as to whether he and his wife continued to benefit financially from Flying Squirrel LLC. That's the name the name previously reported for Teresa Heinz-Kerry's private charter jet company and the registered owner listed on the Federal Aviation Administration's website.
Kerry's 2021 financial disclosure recorded Flying Squirrel LLC under the section for "Spouse's Employment Assets & Income and Retirement Accounts." The financial disclosure estimates the LLC with a value of over $1 million.
It's unclear who chartered the flights. While Kerry was on an international trip in April, flight data showed that the jet traveled to Idaho from Boston. While the trip's purpose is unknown, the Idaho Press reported last year that he and his wife, Teresa, have been part-time residents in the nearby Sun Valley for decades.
Kerry has said he offsets his emissions, although it's unclear how.