Maybe Danielion can interject and list the number of errors of logic in the preceding three posts.
1. the fact that there is not a lot of CO2 in the atmosphere does not mean that it has no effect, just like me taking mere 0.0001% of potassium cyanide in my drink does not mean it will have no effect on my health.
2. Extensive modeling of the greenhouse effects on C02 has been done and shown that not only does it cause warming, but the amounts we have contributed can cause significant warming.
Some years ago I've worked with a scientist who was a co-author of one of the UN Reports on Climate Change who's also written several pamphlets debunking common myths and misconceptions (more on that below). He was the first to admit that the precise extent of the warming is very hard to predict. A lot of uncertainty still exists but not in the actual fact of warming, just in the extent. Here's pretty thorough info written by some of the top people in the field (if anyone is interested in getting informed on the subject):
And it's also a good idea to try to inform oneself on the concept of a "trend". For the impatient and the time-challenged:
Here's an interesting read for everybody on how vital issues have been obfuscated by the special interest groups: