A Blood Feast
History of a Lethal Disease
Changing Climate / Changing Habitats
Tracking Temperature Trends
The Carbon Cycle
The Greenhouse Effect
Molecules on the Move: Greenhouse Gases
Fossil Fuel and a Fiery Future
What We Do Now...
Our use of fossil fuels is having a serious impact on our environment.
to this podcast to find out more.
The dinosaurs hadn't even been heard of when fossil fuels started to develop. These fuels -- coal, oil, and natural gas are as old as ... well, fossils. They began as very tiny creatures in seas and lakes and plants and trees on the land. Over time, these living creatures, full of carbon, died. The water creatures fell to the bottom of the seas and lakes. The trees and plants fell into the numerous swamps where they grew. Where time ... Pressure ... And heat forced them to decompose - into the carbon-based substances that we now call fossil fuels. Fossil fuels weren't a very active bunch. They stayed buried in the seas and underground ... "living" in great reservoirs of carbon called carbon sinks. not that kind of sink. And there they stayed. Their carbon didn't circulate through the planet as part of the carbon cycle. It just stayed put. Well, most of it did. Some of it seeped up to the surface from time to time. And people were so entranced with its properties that they eventually went searching for more of it. And what they found astounded them. Fossil fuels could be used for all sorts of things. Like running cars and machinery Heating homes And making playing games on computers and such part of our everyday lives. (Well, not at first) Sounds good, right? But, consider this. When fossil fuels burn, they release their carbon into the air as carbon dioxide. Once it's released, carbon dioxide moves up into our atmosphere and falls into our oceans. And what's happened as a result of moving all those fossil fuels out of the sinks where they stayed for about 300 million years or so? Once in the atmosphere, carbon dioxide begins its work. When heat radiating from the earth strikes the carbon dioxide molecules, the molecules vibrate like crazy, deflecting some of the heat back down to the Earth's surface. And the more carbon dioxide molecules there are in the atmosphere, the more heat. The molecules not only redirect heat back toward Earth. They also slow down heat's escape into outer space. Net effect? Earth's temperature is on the rise. And no, not everywhere. And not all the time. But the trend is definitely there. There are other factors that are pushing up the carbon dioxide levels - such as cutting down the world's forests. But, scientists say that burning fossil fuels - in our cars or to make electricity, for example - now accounts for about 65 percent of the additional carbon dioxide that has accumulated in our atmosphere since the beginning of the Industrial Revolution. Extra carbon dioxide we didn't need in the first place. Haven't we ever heard of letting sleeping dogs lie?