GreenYour.com

3Degrees

In addition to their carbon offset offering, 3Degrees is a leading national supplier of Green-e Certified RECs sourced from a variety of renewable energy technologies, including wind, biomass, geothermal, solar, low-impact hydro, landfill gas, and biogas. Use the footprint calculator to get started on your green energy path.

Atmosfair

This German offset company calculates only emissions from air travel. Funds support alternative energy generation.

Carbonfund.org

Carbonfund.org lets you offset emissions from air and car travel, energy use, and even special events.

Climate Care

Shrink the size of your carbon footprint at home, while you drive, fly, or bask on some faraway beach.

Climate Friendly

Tally emissions from driving, air travel, and home energy. Offset only what you choose. Or pick from one of Climate Friendly's custom packages (including driving, flying, etc.) that let you go carbon neutral just in that area for a year.

GreenLife

GreenLife lets you offset your carbon emissions from home energy use, air travel, and driving. Offset your entire yearly emissions or a portion via one of the company's pre-priced packages or use the online calculator for a more precise tally.

My Climate

Neutralize emissions from flying, driving, and powering your home or business.

Native Energy

Help fund community-based clean renewable energy projects, including methane reduction ventures and wind power initiatives.

Sustainable Travel International

Calculate your entire carbon footprint from air and car travel, energy use, and hotel stays with STI's easy-to-use carbon calculator.

TerraPass

Diminish your eco-impact from air travel, driving, and energy use with TerraPass offsets.

The CarbonNeutral Company

Whether you're a student or business owner, the CarbonNeutral Company lets you tally emissions from flying, driving, running your home, or powering your truck fleet.

Clean Air Limo (Austin, TX)

Austin-based Clean Air Limo—serving Central Texas and the Hill Country—offers "style, service, and sustainability" to green Texans. The company's fleet is composed entirely of hybrids, including makes by Mercedes and Lexus. Available for airport transfers, sightseeing, special events, and more.

DrivenEco (New York City)

Need chauffeured hybrid wheels? Look no further than DrivenEco. Serving New York City and its environs for events both business and personal.

ECOLIMO (Los Angeles, San Francisco, Washington DC)

Their fleet includes hybrids, biodiesel- fueled vehicles, and compressed natural gas (CNG) powered options.

EcoShuttle (Portland, OR)

All aboard! Hire one of EcoShuttle's nine-person, 100 percent biodiesel-fueled vans for a simple airport ride or for a slew of special group events.

Elite Green Car (Atlanta, GA)

Hail (well, hire) one of Elite Green Car's Lexus RX 400 Hybrids to cruise around the ATL in sustainable style.

Evo Limo (Los Angeles, CA)

Their fleet of uber-lux suburbans and sedans have been converted to run on compressed natural gas (CNG) yet still come with mini-bars, tinted windows, and entertainment systems.

Green Car Limo (San Francisco Bay Area)

Swapping traditional stretch limos with a Toyota Prius fleet, Michael Fadis' Green Car Limo service has been serving the Bay Area since 2005.

Green Limousine (Vail, CO)

Want your next trip to the Colorado Rockies to be a bit greener (and sans the hassle of navigating snowy conditions yourself)? Book a ride with Green Limousine, a car service with a fleet of biodiesel-fueled sedans and SUVs.

Green Shuttle of Cape Cod (MA)

Visit one of the Northeast's most popular summer playgrounds, Cape Cod, while curbing your carbon tiremark. Get picked up in a Prius, Altima, or Mercury Mariner at various points in New England such as Boston Logan Airport and Providence's Green Airport.

Greenfleet Car Service (New Jersey)

Garden State-based Greenfleet Car Service specializes in corporate travel to and from airports, personal travel, group outings, and conventions.

greentomatocars (London, UK)

With a fleet of private hire hybrids, greentomatocars is the greenest ride in London (they'll also transport you to other points in the UK). And they offset emission with tree-planting and various eco-friendly projects.

New York Hybrid Car & Limousine Services

Offering airport pickup and drop-off, special occasion, sightseeing, and out of town services with "all hybrids all the time," New York Hybrid is a great alternative for your transportation needs.

OZOcar (New York City)

Driving around the Big Apple can be a big pain in the you know what. Why not hire OZOcar, NYC's first hybrid luxury car service, to do the driving for you?

PlanetTran (New England, San Francisco Bay Area)

Are you a green-minded traveler flying into San Francisco, Oakland, San Jose, Boston, Providence, or Manchester, New Hampshire? Give PlanetTran a buzz and they'll pick up you and your bags in a Toyota Prius and deposit you at your destination the sustainable way.

Avis (nationwide)

Avis offers the Toyota Prius hybrid to renters in various locations.

Bio-Beetle (Los Angeles, CA; Maui, HI)

Bio-Beetle offers biodiesel-compatible cars including Volkswagen Beetles, Golfs, and Jettas to rental customers in Maui and Los Angeles.

Budget (nationwide)

Budget guarantees the availability of the Toyota Prius and Nissan Altima hybrids along with other fuel-efficient vehicles.

Electric Time Car Rentals (San Francisco, CA)

Enjoy the sights and sounds of San Francisco in an eye-catching, non-polluting electric car; GPS-based audio tour is optional.

Enterprise Rent-A-Car (nationwide)

Enterprise Rent-A-Car offers renters hybrid and flex-fuel vehicles at various locations.

EV Rental Cars (Los Angeles, San Diego, San Francisco, Oakland, Santa Ana, San Jose, CA; Phoenix, AZ)