Yesterday's "Ask An Expert" feature on Scientific American
dealt with the question of carbon dioxide – a lot of which comes out of our tailpipes – and its connection to global warming. Pieter Tans, a senior scientist at the NOAA Earth System Research Laboratory, answered the question and does a good job explaining the greenhouse effect, how a small change in the amount of CO2 affects temperatures on the entire planet and how the overall rise in heat due to the long-lived greenhouse gasses is about the same as if the sun "had started to shine 1 percent more brightly during the 20th century". The trend will continue, he writes, since the oceans are still heating up and as they do, the Earth's surface will warm at least another half-degree Celsius (and that's if we stopped putting CO2 into the atmosphere right now, which will not happen).
[Source: Scientific American]