Many U.S. climate activists, including Biden administration climate envoys John Kerry and Mike Bloomberg, celebrated Earth Day on Thursday and praised the administration's latest emissions goal — even after facing questions about how their personal private jet use harms the environment.

Kerry and Bloomberg have been known to travel on private jets while addressing climate change, even as other environmental activists, like Greta Thunberg, travel across the Atlantic Ocean by sailboat. Private jets have been estimated to emit upward of 40 times as much carbon per passenger as commercial flights.


President Biden's climate czar Kerry, who took heat for flying private to Iceland to receive a climate leadership award in 2019, shared an Earth Day message Thursday.

"As @POTUS reminded us, 'We will lead not merely by the example of our power but by the power of our example.' This Earth Day we're working hard to lower our emissions [and] encouraging other countries to do the same. This is how we solve the climate crisis. Together," Kerry wrote on Twitter.

Kerry presented a bleak picture of the climate situation during a Washington Post livestream Wednesday.

"But the challenge is this: The United States could go to zero [emissions] tomorrow. ... We'd still have a problem. The world would still have a problem. If China went to zero tomorrow with the United States, we'd still have a problem," he said. "Every country has to come to the table. This is the single biggest multilateral, global negotiation that the world has ever needed, and the stakes could not be higher."

"We hear people talk about this being existential. For many people on the planet, it already is," Kerry said.

Special Presidential Envoy for Climate John Kerry speaks during a press briefing at the White House, Wednesday, Jan. 27, 2021, in Washington. (AP Photo/Evan Vucci)

Kerry appears to have flown across the country in a private jet as recently as last month. A jet belonging to Kerry's family made its way from Massachusetts to Idaho, where he and his wife reportedly live part time. FlightAware logs show that the jet traveled from Bedford, Mass., to Martha's Vineyard, which is also in Massachusetts, on March 26, and from Martha's Vineyard to Boston on March 28.

In the past, Kerry has encountered scrutiny over use of his family jet while speaking out against climate change. Most notably, when Kerry took his jet to receive a climate leadership award in Iceland, he called it "the only choice for somebody like me who is traveling the world to win this battle."


It's unclear how Kerry has been offsetting his carbon output, as he claimed in 2019, but flight logs indicated 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. 

Like Kerry, United Nations climate envoy Bloomberg has eschewed commercial travel for his emissions-heavy private jet. Flight records show that Bloomberg’s private jets took more than 1,700 trips and emitted at least 10,000 metric tons of CO2 from August 2016 to August 2020, a Business Insider analysis found. It's unlikely that Bloomberg himself was on every flight.

In this Feb. 3, 2020, file photo, Democratic presidential candidate former New York City Mayor Mike Bloomberg addresses supporters during a campaign stop in Sacramento, Calif. (AP Photo/Rich Pedroncelli, File)

Bloomberg praised the Biden administration Thursday for announcing a new goal of cutting U.S. greenhouse gas pollution in half by 2030.

"The Biden administration's new climate goal — to more than halve emissions by 2030 — is an important step that shows it is serious about leading on the climate crisis," Bloomberg said in a statement. "Cities, businesses, and other local organizations have been leading the fight and making important progress through groups like America Is All In. Now, they have the chance to go further and faster if the federal government backs them with real resources and support."

Actor Leonardo DiCaprio, who has spoken out about climate change for years, shared an Earth Day message as well.


"Our planet is in a state of climate emergency. But there's hope if we #ActNow. This #EarthDay, join me in demanding bold & credible #ClimateAction. For ourselves and for future generations," DiCaprio wrote on Twitter along with a link to the UN's climate action webpage.

However, the actor has also repeatedly drawn criticism for his use of a private jet to attend events. Following an appearance at Global Citizen in New York in 2019, DiCaprio was widely mocked for his use of yachts and private planes.

"I would love to hear what he is saying but his enormous carbon footprint is blocking the speakers," wrote one Twitter user in response to a Hollywood Reporter article.

Fox News' Sam Dorman, Morgan Phillips and Bradford Betz contributed to this report.