In total, the private jet tied to President Biden's point person in the effort to lower greenhouse gas emissions took 16 flights since January — raising questions about how much his family contributed to the problem.
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.
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 confirmed 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." It "FLYING SQUIRREL, LLC - 12/31/2020" with a value "Over $1,000,000."
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. Other reporting indicates he's been using commercial flights.
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. It's unclear what the trip was for but the Idaho Press reported last year that he and his wife, Teresa, have been part-time residents in the nearby Sun Valley for decades.
Some of the 2021 flight logs showed multiple trips between Massachusetts and Idaho. A handful of trips involved flights to California.
Private jets have been estimated to emit upward of 40 times as much carbon per passenger as commercial flights.
Kerry has said he offsets his emissions, although it's unclear how. Flight logs indicated that his family's private jet spent over 20 hours in the air from February of last year to January — culminating in an estimated 116 metric tons of carbon emissions.
For comparison, a March 2018 report from Environmental Protection Agency estimated that the typical passenger vehicle emits about 4.6 metric tons of carbon dioxide per year. That calculation assumed a car that drives around 11,500 miles per year with a fuel economy of about 22.0 miles per gallon.
Kerry's most recent financial disclosure valued the private plane at more than $1 million.
The White House did not immediately respond to Fox News' request for comment.
Fox News' Peter Hasson contributed reporting.