Matt Hickman unravels the mysteries behind offsetting CO2 and buying RECs. (Hint: One of them can fund tree-planting efforts.)

Norfolk Southern is working with GreenTrees LLC on a five-year reforestation project.

Buy a ticket for your chance to winning millions while fighting climate change.

A new website makes it super easy to help save the world, a little bit at a time.

COTAP will focus its carbon offsetting projects in impoverished countries.

Polio could be wiped out by 2018, but Gates says it will require investment and hard work.

Your car could capture and store carbon dioxide for later disposal, making it zero climate emission even without batteries.

Mary Barra is a GM insider, but she's also a change agent who will continue the company's aggressive comeback.

Olivine is a miracle green rock that absorbs carbon dioxide naturally from the air.

Rarely use your car but keep it around for emergencies? Try a car sharing service.

Traffic driving you crazy? Let MNN get you on track to a more astute commute with these carpooling and public transit tips.

Type in your destination, and Cost2drive figures out your gas costs and CO2 emissions.

An interview with author Alan Durning on his family's year of living car-lessly.

My new bike has a lithium-charged motor that kicks in just enough added oomp to power me through hills and headwinds.

Video: Sabrina Bryan and Robbie Amell give you their eco-tips.

Video: Get your green tips from Amanda Seyfried and Olesya Rulin.

Car-sharing service Zipcar is betting that name recognition will boost sales of its common stock in an upcoming initial public offering.

Officially called the "3D fast bus," the bus will literally straddle the road and carry passengers over cars and under overpasses.

Morieka Johnson can help you maximize those trips to school, tae kwon do, gymnastics, soccer ...

Many city dwellers are opting to give up driving their own cars for a month to take Zipcar's Low-Car Diet challenge. Could you go car-lite for 30 days?

If you're a San Francisco resident, 30+ years old, and have a clean driving record, you can rent a Tesla for $25 an hour through Getaround.

Car sharing service Zipcar will be adding Toyota Prius plug-in hybrids to its fleet.

"Why do you have to sing everything like you just swallowed a pair of jazz hands?!"

Video: When a 10-mile stretch of L.A.'s interstate 405 is closed this weekend, there will be only one way to get through the gridlock: Fly over it. Take a ride

If a celebrity endorsement gets kids using a phone app that prevents on-the-road texting, emailing and phone use, who am I to complain? But, for the record, Jus

Personal car-sharing spreads in the U.S., from California to Oregon and, very soon, to a neighborhood near you. The concept of hiring out your own vehicle has p

Driving with a burger in one hand and a cellphone in the other is a sure recipe for highway disaster. And all that old food is hanging out, just waiting to give

GM owners with an OnStar-equipped vehicle can earn some extra cash by renting out their autos.

A 10-mile stretch of Los Angeles' 405 Freeway — the most heavily trafficked road in the country — was completely shut down this weekend as part of a $1 bill

Avis acquires zipcar, but what does it really mean?

mexico city public transit

Save money and reduce your carbon footprint when you use one of these 7 apps to organize a carpool or book a carshare ride.

Apply to the 30-Day Electric Bike Challenge and you could be selected to receive an e-bike for a month in exchange for swearing off the use of your car.

Enterprise is expanding its carsharing services despite a company executive’s dismissal of the need for a separate carsharing industry.

Bicycle sales exceed cars in Europe, and there's compelling evidence that pedaling increases the national happiness quotient.

Studies show that drivers older than 85 get into fatal accidents almost 4 times as often as teens do, and intersections are a problem.

We're driving fewer miles and more of us are going car-free, yet we're only scratching the surface of car-isn't-king culture.

Two new studies decipher who prefers which kind of car, revealing unexpected attitudes that challenge many assumptions.

Which form of travel gives off the fewest emissions? Let's just say it pays to carpool.

Public transit has long been undervalued as a mobility option. Thanks to new technologies and new ways of living, that's changing.

Looking to reduce pollution and congestion, European cities are banning vehicular traffic — and creating vibrant shopping zones in the process.

Uber and Lyft are both offering discounted ridesharing services. Today in San Francisco; tomorrow the world.

Helsinki is experimenting with a plan to match people with rides, making cars unnecessary.

As millennials turn away from driving and car ownership, will college students finally stop keeping cars on campus?

Car2Go is now the world's largest service, with a million members and a new outpost in Brooklyn.

Automakers like Volvo, VW, BMW, Audi and Mercedes are going full speed ahead, aiming for autonomous cars on the road by 2025.

What is Uber anyway? Is it a taxi service or as it claims, a technology platform, or something else altogether?

FlightCar leverages all those idle vehicles in the long-term lots, and it's a lifeline for frequent flyers.

A new report from KPMG sees 500 billion annual miles from people who might have otherwise stayed home.

You can now get a charge out of its new go-anywhere GoCharger.