Cupid must be spending some time in Knoxville, Tenn. At least that is the finding of a new poll by Amazon.com that named Knoxville the most romantic city in the

New research from the University of Kansas finds that ride-booking apps have helped to free up ambulances.

These are just a sample of the things we could lose if temperatures rise 5.4 degrees Fahrenheit over the next 200 years.

Volunteers help scientists understand birds and changing habitats.

Ford has announced the 19 markets that will receive the first wave of the Focus Electric in late 2011.

Denver and Oakland vote to decriminalize magic mushrooms, showing support for psychedelic drug psilocybin. Other cities have similar laws on tap.

Researchers have found 10,000 natural gas leaks under just two U.S. cities, hinting at a broader problem.

Kids living just outside the evacuation zone will be tested for cumulative radiation exposure.

Several German cities are planning to fight air pollution by eliminating fares on public transport.

The air at 85% of national parks is unhealthy at times, report finds, building on a study that said concentration of smog-forming ozone rivals that of cities.

More than 7,000 cities in 172 countries are expected to take part in the one-hour event on Saturday.

A new online investing platform will fund energy-efficiency improvements for churches and nonprofits in poor neighborhoods.

Six months after leaning they were or were not going to be getting one of NASA's retired space shuttles for display, museums in Los Angeles, Houston and New Yor

More than 100 cities across the globe get 70 percent or more of their energy from renewable sources, according to London-based CDP.

It’s time to ditch the word "senior" and all the ageist baggage that goes with it.

A new study by WHO finds that air pollution has worsened since 2011, signaling increased health risks for city dwellers.

When the Winter Olympics wrap up, Vancouver will be passing more than one torch. The city could light the way for green cities of the future by proving economic

Right now, we basically build cities in a way that worsens flooding events, but nature has solutions.

How do these global cities stack up in being green?

When you're out on the trail, a little etiquette can take you a long way.

Flash Drives for Freedom aims to take old USB sticks and smuggle them into North Korea loaded with Western media.

Eclipse glasses distributed to the homeless, plus where to donate your old eclipse glasses if you don't plan on reusing them.

With frigid weather throughout the country, communities offer the homeless respite from the dangerous temperatures.

St. Louis, Orlando and Minneapolis are featured in a new Sierra Club report on the growing number of American cities rejecting fossil fuels.

Perfect for blustery apartment balconies, the student-designed O-Wind Turbine is a national winner of the James Dyson Award.

The two cities will receive substantial financial and technical assistance from Bloomberg Philanthropies to help combat combat climate change.

Migration forecasts developed by researchers at Cornell University help cities and building owners determine the best time to flip the switch.

London, Houston and Bangkok are among the cities most vulnerable to sea level identified in a new report by London-based charity Christian Aid.

The World Cities Culture Forums' ranking of member cities with the highest and lowest percentages of urban parkland doesn't come without surprises.

Here are 14 of the oldest continuously inhabited cities in the world.

New research shows that urban green space largely benefits the wealthy and educated, not the underserved communities that need it most.

Many city dwellers leave urban areas to visit lakes and rivers, but these cities are ideal for people who don't want to travel far to swim, paddle or surf.

Researchers from the University of Wisconsin-Madison find that city blocks with 40% or more tree coverage are naturally cooler than blocks with fewer trees.

The Citi branch in Union Square received LEED Platinum certification.

You can make a difference for environmental science while traveling, whether you're going to the beach, visiting a park or sticking to cities.

Iconic landmarks and skylines all across the globe were plunged into darkness on Saturday for Earth Hour.

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

By reducing the urban heat island effect, mass adoption of electric vehicles may even cut our air conditioning bills.

The EveryDrop LA app makes it easier for ordinary Los Angelenos to identify and report sources of wasted water in their communities.

In its magnificent mini-epic 10-part series, "Moving Beyond the Automobile," Streetfilms has created a handy, eye-catching primer to the most important transfor

Paris can be pretty unfriendly to tourists, but SmarterParis is a friendly new app that can make it easier.

Miss the smells of home? Artist Kirill Rudenko is canning air from many of the world's major cities and selling it for 10 dollars a pop.

This is not a tempest in a disposable teacup, but a very big problem.

Volunteers can lend a hand, from categorizing whale songs to planting sunflowers.

The website FlightNetwork features 50 of the world's most beautiful cities, as chosen by 1,000 of the world's top travel professionals.

Americans are experiencing one of the worst allergy seasons in years. Here are the 12 worst cities out of 100 ranked by the United States for allergy sufferers.

30 of the world's largest cities have reduced greenhouse gas emissions.

The way we use our cities has changed, the forces that drive them, all driven by the phone. It's also likely that we ain't seen nuthin' yet.

We'd like to know your thoughts on sustainability initiatives and what's needed in your community. Participate in this quick sustainable cities poll.

If people from any age group can't move to a walkable city, then they're going to have to fix what they've got.