Why is the carbon dioxide in our atmosphere so important?

 Why is the carbon dioxide in our atmosphere so important?

We should all be thankful for the carbon dioxide in our atmosphere. This gas is important in maintaining the Earth's surface temperature by creating a greenhouse effect. Carbon dioxide (and smaller amounts of other greenhouse gases, such as methane) form a kind of "greenhouse glass" barrier, keeping temperatures higher than if there were no greenhouse gases. Carbon dioxide absorbs some of the heat, keeping it near the ground and raising the average surface temperature. In fact, without the greenhouse effect, the oceans would freeze, and life as we know it would not exist.

Scientists are debating whether the carbon dioxide that humans add to the atmosphere, as a result of industry, transportation, and sundry other processes, can eventually cause catastrophic changes in the Earth's surface temperatures. Many scientists believe we are already seeing the effects of the more than 25 percent rise in carbon dioxide that humans have added to the atmosphere since the beginning of the industrial age around 1750. Since that time, the planet's overall surface temperatures have warmed by at least 1°C. But no one knows how much extra carbon dioxide - even gas additions from natural causes - is truly detrimental.