I just did a quick search and found several graphs, but they only go back about 1000 years. They show the approximately 80ppm variations you refer to, and then they show the increase to about 100ppm above anything in the past 1000 years...coincidentally beginning around the time we started burning fossil fuels.Originally Posted by masdog
Ignore my comment about forests. I didn't mean to suggest that was a significant issue, just an example of something we know for certain.
I've heard the argument about volcanic activity before. I could be wrong, but I thought volcanic activity was something that is slowly decreasing as the earth's core cools. Is there any data to show volcanos started producing more CO2, around the same time we started burning fossil fuels?
Organic matter has always been decomposing, so I don't see how that argument works. If there is an increase in decomposing organic matter, I'd be surprised if humans didn't have something to do with it.
There was a time when they thought the earth was flat too. We'd be foolish to expect 100% accuracy from our scientific community, but relying on the statistically unlikely possibility that the scientists are all wrong would be much more foolish, IMO.Originally Posted by masdog
I may be wrong about that, in terms of largest temperature changes. What I meant to say is that the changes are most easily observed at the poles (or any extreme cold environment). And I don't think the concrete in urban environments has anything to do with what's going on at the poles.Originally Posted by masdog
The climate models don't change my opinion one way or the other. While I do think the data going in to the models is accurate for the most part, I don't know if all of the necessary data is being included. Any time a system as complicated as our climate is modeled on a computer, assumptions are made to simplify the algorithms. That's where I suspect most errors would appear, but I still think we can learn something from them.Originally Posted by masdog
I guess what frustrates me about this argument (and I'm not directing this to you specifically) is that so many people seem to just ignore the issue, or decide it's not an issue at all, just because there is a lack of certainty. People also exaggerate the level of uncertainty to make it sound like there is much more debate in the scientific community than there really is. For the most part, on the biggest issues, the scientists agree.Originally Posted by masdog
The only thing I know for sure is that we should take this seriously and not just dismiss it. If this were a foreign policy issue that involved national defense, we would be extremely cautious, maybe even preemptive. But since it's the scientists that are worried, instead of the politicians, we'd rather sit back and do nothing until it's too late. The politicians' track records are no better than the scientists' and they may be worse.
Paul