Carbon Cycle BrainPop

Dear Tim and Moby. What can you tell me about the carbon cycle? From Atul. All carbon is the fourth most common element in the universe. It's the building block for all life on earth, every single cell in every living thing contains some carbon. Carbon is common in the nonliving matter too, in rocks and soil, dissolved in seawater, inside the earth's mantle, and in the air as carbon dioxide. Earth's carbon is constantly flowing from one of these forms to another. That's the carbon cycle. Beep. It's like the water cycle only a bit more complex. Animals add carbon dioxide to the atmosphere when they breathe. And plants soak up carbon dioxide during photosynthesis, storing the carbon in their cells, plants, especially trees are known as carbon sinks because they take more carbon out of the atmosphere than they add to it. The oceans are carbon sinks too, thanks mostly to marine life, ocean soak up more carbon dioxide than they release. When plants and animals die, the carbon contained in their bodies enters the earth's crust. Let's cross keeps carbon locked up for millions of years, eventually returning some of it to the atmosphere through volcanic eruptions. Normally, the carbon cycle keeps a pretty steady level of carbon dioxide in the atmosphere. Lately, the cycle seems to have been thrown out of balance, more and more carbon dioxide is entering the atmosphere every year. Beep. It's probably because of human activities. It creates tons of carbon dioxide by burning fossil fuels, and the clearing of rainforests in South America and Africa makes the problem worse in two ways. First, the burning trees add carbon dioxide to the atmosphere, and second, once the trees are gone, they're not soaking up any more carbon dioxide. Beep. Right, carbon dioxide is a major contributor to the greenhouse effect. That's the warming up that the earth experiences because of certain gases in our atmosphere. Gases like carbon dioxide trap heat in the atmosphere and keep the earth warm. Since the start of the industrial revolution about 200 years ago, the carbon in the Earth's atmosphere has increased by about 40%. Both scientists agree that this has warmed the earth up, and that the warming could have devastating effects on the environment. Planting forests and finding alternative energy sources will help restore the balance, but we've got a long way to go. That should help too.