The "evidence" that exists is that it has been getting a bit warmer; few people disagree with that.
A lot more than a few people disagree with that, including a significant number of people who have the authority and responsibility to actually DO something about it.
The "debate" is about what that means.
No, we KNOW what it means; we have known for decades what it means to have global temperatures get "a bit warmer". Just like we have known for decades what it means to have global temperatures get "a bit colder". The only serious debate left is what we need to do about it. Not when, because the when is NOW, but what.
Is it going to continue to get warmer?
Yes. The science is VERY solid on this point.
Is there anything we can do about it?
Yes, of course. There are many things we can do about it, but realize that even if we did everything we could, right now, the warming trend will continue for some time due to the enormous inertia of the climate system. What we would be doing right now is reducing the future peak and extent of the warming that will occur for the next few hundred to few thousand years.
Simply put -- we need to STOP putting more excess CO2 in the atmosphere (I use the term "excess" as a pre-emptive anti-stupid-response for those who would counter with trollish strawmen like "ok, let's all stop breathing, then!"). It isn't going to happen in one day, but we need to make a sincere and concerted effort to make it happen as quickly as possible. We need to start looking towards CO2 sequestration technologies to remove the excess CO2 that we've already put into the atmosphere. We need to make plans for the changes that are going to happen anyway from all the past emissions excesses. Is it a big challenge? Yes, enormous; as enormous as the problem itself. Can we do it? I think we are capable; we have mobilized ourselves as a nation for other important tasks in our history.
Should we wash our hands after handling fecal matter and before handling our food? Should we purify drinking water? Should we rotate crops? That's the kind of common-sense question that really doesn't need to be asked, does it?
Indeed. What are the costs of NOT doing something about it, and now? Are they far greater than the costs of doing something about it? Well, see, there are some really smart people who have been working on this particular question -- insurance actuaries -- and we already know their answer. People who are experts in risk management are well aware that the costs of doing nothing on climate change are catastrophic, far more so than most practical abatement and mitigation plans combined, and they are already adjusting insurance plans and premiums to take it into account. I think we should take a cue from them as to what the costs are very likely to be and make decisions to do something NOW.
There are a lot of people who like to confuse the little bit of scientific fact we have with issues of extrapolation, prediction, and policy. That is not science, it is just dishonesty.
"Little bit of scientific fact" You're kidding, right? There are LIBRARIES full of scientific research on this subject. If that is to be considered "a little bit", perhaps we should start questioning the confusion related to the "little bit of scientific fact" we have with things like gravity, biology, chemistry, evolution, etc.
One of the main principles of science involves extrapolation and prediction. That's what the scientific method is all about. How do you think we got to the moon? We didn't have previous attempts by ancient civilizations to guide us, we extrapolated and predicted. We did so smartly and very carefully, but that's what we did.
When the weatherman predicts a big, dangerous storm heading your way, do you think it is a good policy to ignore it and do nothing to prepare for it until it is blowing your house down?
Do you really consider that *dishonest*? Really?