Environmental Science

Water is one of the most abundant substances on the planet. About 70 percent of our planet is covered by oceans, but just how much water is there on Earth?

By HowStuffWorks.com Contributors & Yara Simón

We know that paper comes from trees, but just how much does it take? Let's do the math and figure out how much paper your average tree can be made into.

During the summer I am always hearing about ozone warnings in my city. This ozone is bad. But then I hear about the ozone layer, which is good. How can ozone be both good and bad?

Charcoal is carbon. Activated charcoal is charcoal that has been treated with oxygen to open up millions of tiny pores between the carbon atoms. What does this have to do with its absorbancy?

Gravity is a force that we experience every minute of our lives, but hardly notice or give a passing thought to in our daily routines. Have you ever wondered what gravity is and how it works? Learn about the force of gravity in this article.

By Julia Layton & Austin Henderson

One way to store energy is to use a battery, but what other ways can we store energy? Learn about different ways to store energy at HowStuffWorks.

By Yara Simón

Let's say you have a nice fire going, and it's reduced down to a pit of hot "glowing embers." If you now toss a piece of wood, or even a sheet of paper, onto this fire, you see a huge puff of smoke as it heats up.

An oscilloscope measures the voltage and frequency of an electric signal. A machine uses "sweeps" and and an input signal. See how it all comes together.

You've probably seen solar panels on satellites, call boxes, road signs, homes and businesses. But how do solar panels work?

By Scott Aldous & Talon Homer

In its purest form, it's odorless, nearly colorless and tasteless. It's in your body, the food you eat and the beverages you drink. All forms of life need it. What substance is more necessary to our existence than any other? Water.

By Shanna Freeman

Water is just hydrogen and oxygen, so why can't we do what nature does and combine the two? Unfortunately, it's not that simple, and the results can be rather ... explosive.

By Josh Clark & Jennifer Walker-Journey

The Great Pacific Garbage Patch is the world's largest landfill, and it can be found in the middle of the Pacific. Millions of pounds of trash collect here.

By Jacob Silverman

How do we reduce greenhouse gas emissions? A carbon tax is one answer. A simpler alternative to cap-and-trade schemes, a carbon tax encourages energy efficiency and reduced consumption.

By Sarah Dowdey

The Sierra Club lobbies for environmental preservation and engages members in fun wilderness excursions.

By Sarah Dowdey

On a planet that is 70 percent water, people don't have enough clean, safe water to drink. We're in a water crisis, and water rights are becoming a big issue. What happens if we just plain run out?

By Josh Clark

The sea scorpion may have been the largest bug to ever live on the Earth, according to a recent find. Learn more about the giant sea scorpion.

By Josh Clark

It's evident the debate over climate change is a heated one. Are skeptics clouding the public judgment for money? Are climate-change believers merely alarmists who risk the present for the future?

By Josh Clark

Crews have to race to contain the damage from major oil spills to prevent damage to beaches, death to marine life and birds, and devastation to local wetlands. So how do they clean them up?

By Josh Clark & Sarah Gleim

Are dinosaurs real? Most people don't have to travel too far to answer that question in the affirmative with some kind of exhibit displaying dinosaur fossils. Or simply look at any bird you can see outside your home.

By Tracy V. Wilson

Hieroglyphics used to be a language that no one -- Egyptian or otherwise -- could decipher. With the help of the Rosetta Stone, that all changed.

By HowStuffWorks.com Contributors

Consumers are becoming more and more knowledgeable about food safety and their health. As a result, organic farming has entered the agriculture mainstream. But what methods must be used, and how is organic farming certified?

By Maria Trimarchi

The 1993 movie "Jurassic Park" did a good job of bringing the idea of cloning dinosaurs into popular culture. It portrayed dinosaur cloning in a way that made sense to a lot of people, but is it really possible?

By Tracy V. Wilson

Every time a new fossil is found, one of the first things scientists determine is how old that fossil really is. But how do they determine it, and how can they be completely accurate?

By Tracy V. Wilson

Have you ever wondered what happens when you flip a switch to turn something on? You're completing an electric circuit, allowing a current, or flow of electrons, through the wires.

By Sidney Soclof

Saber-tooth cats have long been likened to tigers, but they aren't tigers at all. While they share some physical traits and hunting practices with tigers, saber-tooth cats are also quite different.

By Tracy V. Wilson