Joe Biden

Former vice president

Biden's campaign is offsetting emissions, a spokesman told The Post.

Bernie Sanders

U.S. senator, Vermont

“Our campaign offsets all carbon emissions produced from travel activities and events by investing in renewable energy and carbon reduction projects,” a campaign spokesman told The Post. “Bernie Sanders is a champion in the fight for climate justice and knows we need to address our emissions through action, not just rhetoric. Bernie is proud to lead the way in the fight against climate change by acting boldly to move our energy system away from fossil fuels and towards sustainable energy sources.”

Elizabeth Warren

U.S. senator, Massachusetts

“Climate change is a threat to the safety and health of Americans — and it disproportionately impacts our most vulnerable communities. I’m in this fight all the way — and that includes offsetting emissions in this campaign,” Warren told The Post.

Cory Booker

U.S. senator, New Jersey

“As a campaign we make every effort to reduce our carbon footprint, including by renting a highly energy efficient headquarters, encouraging public transit use for our employees, and engaging in recycling,” Booker told The Post.

Julian Castro

Former mayor, San Antonio

Castro's campaign is working to reduce its carbon footprint, he told The Post.

John Delaney

Former U.S. representative, Maryland

“We have implemented an environmentally friendly approach to all of our campaign offices and our use of renewable resources. We prioritized having LEED certified and Metro accessible office space for our MD headquarters and reducing the carbon footprint of our campaign travel,” Delaney told The Post.

Tulsi Gabbard

U.S. representative, Hawaii

Gabbard’s campaign is taking steps to reduce its carbon footprint, a campaign spokeswoman told The Post.

John Hickenlooper (Dropped out)

Former governor, Colorado

Hickenlooper is no longer running for president. Hickenlooper’s campaign is taking steps to reduce its carbon footprint, a campaign spokesman told The Post.

Amy Klobuchar

U.S. senator, Minnesota

Klobuchar's campaign is tracking its carbon footprint and working to reduce it, a campaign spokesman told The Post.

Wayne Messam

Mayor, Miramar, Fla.

“The Wayne For America Campaign has implemented environmentally conscience practices,” Messam told The Post. “Our offices have LED lights. When traveling we rent vehicles that have high fuel efficiency and look for options to use public transportation.”

Seth Moulton (Dropped out)

U.S. representative, Massachusetts

Moulton is no longer running for president. “We are working on tracking the carbon footprint of our campaign and are always looking to reduce it,” Moulton told The Post. “We as an office have a preference for rail transport, have gone paperless, and are located in a coworking space to share resources.”

Eric Swalwell (Dropped out)

U.S. representative, California

Swalwell is no longer running for president. “I have signed the No Fossil Fuel Money pledge, agreeing to not accept donations from the oil, gas, and coal industry,” Swalwell told The Post. “Our campaign headquarters leases space in a building with updated, energy-saving lighting and heating systems, earning city and regional green-business certifications. We’ve made energy-efficient choices in our computers, copiers and other office equipment. I always want to walk the walk, and my campaign is exploring options to make sure that we really undo our emissions and we're not just buying hot air.”

Andrew Yang

Tech entrepreneur

Yang’s campaign is taking steps to reduce its carbon footprint, the campaign told The Post.

Michael Bennet

U.S. senator, Colorado

“We just launched a few weeks ago, and we will certainly take a look at this,” Bennet told The Post.

Pete Buttigieg

Mayor, South Bend, Ind.

Buttigieg’s campaign is looking into how to address its carbon footprint, a campaign spokesman told The Post. “I’m interested in decarbonizing the fuel that goes into air travel. I also don’t believe we're going to abolish air travel. This is a big country. And while I absolutely think we can do more to provide alternatives, like trains, I don’t think that we’re going to solve the question on how to get around the world without air travel. This is the sort of thing that I think we need to look at in a commonsense kind of way. ... Sometimes I fly because this is a very big country and I’m running to be president of the whole country,” Buttigieg said when his use of private air travel was questioned at a CNN climate town hall

Bill de Blasio

Mayor, New York City

De Blasio's campaign said it was "looking into" reducing its carbon footprint.

Jay Inslee (Dropped out)

Governor, Washington state

Inslee is no longer running for president. “I believe that the most important thing that a presidential campaign can do to address climate change is to make it the top priority and put forward concrete plans to defeat climate change of the scale called for by the science, the existential threat posed by climate change, and the opportunity involved in the creation of a clean energy economy,” Inslee told The Post.

Beto O'Rourke

Former U.S. representative, Texas

“In order to reach our ambitious climate goals, everyone will have to sacrifice and do their part to reign in the use of fossil fuels. We are currently looking at various ways we can address the campaign’s carbon footprint through rigorously verified offsets certified by American Carbon Registry, Climate Action Reserve, or Verra — especially those that spur conservation and create new profit opportunities for farmers and ranchers.”

Tim Ryan

U.S. representative, Ohio

“I believe it is important for every citizen to do their own part, however small, to help reverse climate change. My campaign will lead by example and plans to stand by those goals,” Ryan told The Post.

Joe Sestak

Former U.S. representative, Pennsylvania

Sestak's campaign is looking into how to address its carbon footprint, he told The Post.

Marianne Williamson

Author

Williamson's campaign is looking into buying carbon offsets for travel and other activities, a spokeswoman told The Post.

Steve Bullock

Governor, Montana

Bullock did not answer this question by publication.

Kirsten Gillibrand (Dropped out)

U.S. senator, New York

Gillibrand is no longer running for president. Gillibrand did not provide an answer to this question by publication.

Kamala D. Harris

U.S. senator, California

Harris did not provide an answer to this question by publication.

Tom Steyer

Billionaire activist

Steyer did not answer this question by publication.