Leonardo DiCaprio, one of Hollywood’s biggest environmental advocates, is getting ready to host his annual gala to fund his Climate and Biodiversity projects. The event will take place late July in St. Tropez, forcing star studded attendees to fly 12,000 miles to the event from Los Angeles, releasing tons of carbon dioxide along the way.

A source close to DiCaprio told FOX411 the actor “is flying commercial." 

The actor’s event, The Leonardo DiCaprio Foundation Annual Gala To Fund Climate and Biodiversity Project, reportedly raised $40 million last year. According to the Daily Mail, if one of A-listers travels from LA to St. Tropez privately, the 12,000 mile round trip will burn 86 tons of carbon dioxide. But the source also claimed, "Many donors and guests are already in or near St. Tropez during this time of year." No more specifics were given.

Kate Hudson, Kevin Spacey, Robert DeNiro, Charlize Theron, Cate Blanchett, Penelope Cruz, Marion Cotillard, Scarlet Johansson and Arnold Schwarzenegger are just several of the A-listers that are expected to attend.

Chip Knappenberger, Assistant Director Center for the Study of Science Cato Institute, told FOX411 the actor’s passion has gotten in the way of practicality, and he is setting a poor example.

“Putting on this type of ‘Hollywood’ gala is very energy intensive,” he explained via email. “Doing so in a ‘green’ way is very expensive. So the example he is setting is a poor one. You can’t live it up and go green simultaneously unless you are very wealthy. In a practical sense, going green, affordably, means sacrifice. Sacrifice is something that is perhaps palpable to some in the wealthy class (although not on display when it comes to DiCaprio’s lifestyle) but something that the less well-off are not as keen on.”

It is possible the actor will fly commercial because he has, in the past faced, accusations regarding his love of pollution-causing private jets and yachts. In May, he took a private jet 8,000 miles to collect an environmental award from Cannes to New York and then back to France. That flight emitted 55 tons of carbon dioxide in the air.

And hacked emails from Sony, released by WikiLeaks, revealed the environmentalist traveled by private jet six times over the course of two weeks on the studios’ dime in 2014.

Knappenberger said the environmental impact of the gases emitted by DiCaprio’s gala are negligible but the social impact is significant.

“While the direct environmental impact of the greenhouse gas emitted by Leo’s gala are negligible (because in the grand scheme of things, the annual global carbon dioxide emissions are far greater and the climate is not very sensitive to greenhouse gas emissions), the social impacts are not — they highlight the hypocrisy of elite 'green' class, and probably turn off more folks than they bring to his cause.”

And while DiCaprio drives environmentally friendly cars, including a Fisker electric car and a Prius, and rides a bike around New York City, he owns multiple homes which use a lot of energy, including a $4 million apartment in New York, a Malibu beach house with a guest house, and a $5 million Palm Springs mansion.

And just months ago the actor dedicated his acceptance speech at the Oscars to climate change.

“Climate change is real, and it’s happening right now,” he said. “It is the most urgent threat facing our entire species, and we need to work collectively together and stop procrastinating. We need to support leaders around the world who do not speak for the big polluters or the big corporations, but who speak for all of humanity, for the indigenous people of the world…and for those people out there whose voices have been drowned out by the politics of greed.” 

In 1998, DiCaprio launched the Leonardo DiCaprio Foundation to support environmental and sustainability issues, which has granted over $30 million to projects in more than 44 countries.  

Professor Michael Hoffmann, a climate change expert at Cornell University, says we all can do a better job at helping the environment, DiCaprio included.

“As individuals our individual contribution is small but as aggregate it’s important,” Hoffmann says. “If we drove a little less, turned the lights out at home, that would reduce our energy use. Many of us who own homes can install solar. The opportunities for individuals are wide open. Everyone can also raise their voices, all of us can do that for the sake of the future. Everyone can do a better job.” 

You can follow Blanche Johnson on Twitter @blancheFOXLA.