The Earth's mountains, rivers, animals and rocks have been around for millions or billions of years. Do you know which ones have been around the longest?

National Park and Earth Week are right around the corner — see how much you know about our nation's protected areas.

From the cheetah to the hare, so many creatures are wickedly quick. Test your trivia smarts on what makes them so swift.

Whether you're crying tears of joy or crying over spilled milk, how much do you really know about the tears rolling down your face?

Lightning is more than just a stunning spectacle. Take our quiz to see how much you really know about this electrifying natural wonder.

Think you know everything about that special day of scary movies and sugar highs? Test your Halloween smarts ... if you dare.

You use pasta in sauce, in soups and in salads. But do you know the names of the different pasta types?

It's time for some healthy change. Here are some fundamental truths you need to know about diet, exercise and other wellness goals.

When the going gets tough, some animals get going — to bed. Take our hibernation quiz to see how much you know.

Every two years, the National Science Foundation asks 10 questions to see how much Americans know about science.

Pickens: 'If you don't think that you're gonna see a $200 barrel of oil, you're joking.'

Matt C. Rogers, senior DOE advisor talks about awarding stimulus money for top energy projects.

UPDATE: Van Jones clears up the 'green czar' buzz.

Former Carter advisor and energy guru S. David Freeman will become the 'environmental mayor' of L.A.

Hearth and Home Technologies says 100 million homes can be heated sustainably with wood pellets.

OPT harnesses ocean power with some bright yellow buoys (VIDEO).

Google lays out a plan to make renewable energy cheaper than coal.

Climate activists call for action to strengthen the most important piece of environmental legislation in history.

When it comes to decisions on electricity and energy policy, women do not have the facts they need.

The vision of an energy-efficient super grid that allows powers companies to communicate real-time may be possible through Google-Spectrum Bridge partnership.

A dramatic film explores the physical and emotional challenges of living in a peak oil scenario.

Answer 20 questions to get your resiliency score -- and find out how self and community-sufficient you are.

A study from the Civil Society Institute reveals that party lines divide many people's feelings about global warming, energy independence and green jobs. Here a

Oilman's plan still aims for energy independence, but now focuses on conversion of tractor-trailers to natural gas instead of giant Texas wind farm.

Web site and mobile app help you find the lowest gas prices in your area.

The 57,000-acre San Andres Refuge, which works to restore desert bighorn sheep, launched its quest for energy independence in 2005 and has implemented several s

Renewable energy is a powerful force for the decentralization of Big Energy (and Big Government). It's odd that it isn't more popular in supposedly 'radical' an

Harish Hande launched his solar company to dispel the myth that renewable energy was too expensive for poor people. The West could learn something from him.

For almost 40 years, Art and Nan Kellam lived off-grid on a Maine island, eschewing modern technology, but not each other.

Music for Relief, a charitable network of music greats, wants to help light up the darkest homes in Africa though the Power the World campaign. The goal: Lift m

Rich natural gas deposits off the shore of Israel can meet the country's energy needs well into the next century, provided it can be extracted economically.

Japan's plan to wean off nuclear power could help lead a global push toward cleaner, more efficient civilization, says U.S. energy guru Amory Lovins.

If fracking techniques pollute water supplies, what will happen to beer production?

A well-known Chinese solar power company has filed for bankruptcy, but this may actually be a sign of health for the industry.

Impact Energies sells and leases solar panel systems to people making less than $6 a day in Ghana. It was acquired by Persistent Energy Partners.

El Hierro, the smallest of the Canary Islands, is becoming energy self-sufficient by relying solely on wind turbines and hydroelectricity.

MNN introduces you to the key characters in the Eco-bama drama including Steven Chu, Carol Browner and more.

The Guest-Imator is a digital portion calculator that even considers the amount of leftovers you want to have. It works for vegan meals, too.

Whether it's fresh or canned, pumpkin freezes really well.

Thousands of pounds of moldy cardigans and unsellable denim shorts are being burned in lieu of oil and coal at Västerås near Stockholm.

As far as creative ideas to keep food food from being wasted go, Toast Beer is pretty brilliant.

Sweden is to thank (go figure) for a hot new lifestyle trend known as plogging that encourages participants to beautify cities while burning calories.

Illegal dung dumping is on the rise as the already-strong Dutch dairy sector continues to grow.

Organic supermarket chain EkoPlaza teams with an anti-plastic waste group to launch a supermarket aisle liberated from plastic packaging.

A Product Impact Dashboard tells you exactly how much rubbish was used to create Pentatonic's cushions, tables and serving bowls.

A study found that while plastic bag litter has decreased in the U.K. seabed, other forms of pollution have increased.

While easy to focus on the gross-out factor, the tale of a stranded train filled with sewage sludge shines a light on the complicated afterlife of our waste.

From Buckingham Palace to the BBC, British institutions are putting the kibosh on single-use plastic.

A singular place to say 'I do' in the Seattle area, Brightwater Treatment Plant can process 36 million gallons of wastewater daily.

This weekend will feature several overlapping events meant to combat a growing plague of garbage around the world.