a_unique_person said:
But the they are seeing change, and it is caused by humans, and it is also possible that the worst case scenario will happen. Everyone seems to concentrate on the best case and say so what, they worst case is also possible.
The models are accepted by the majority of the experts in this area as being valid, and are being tuned all the time. For example, the affect of ocean currents on temperature are being incorporated into models. It is nothing new.
Seeing is believing? The central point is we do not know what exaclty we are seeing. The climate has always changed, that is what it does. Is this present phase anthropogenic or just as natural as changes in the past. Despite your own self assurance and in contrast to your claims, it is not obvious to me or to "experts".
The so called "global mean temperature" records are a classic example. It consists preominantly of land based data with a small coverage of the earth, it is not very reliable (accurate temperature monitoring across Africa - yeah right) it is distorted by micro climate effects around monitoring stations that tend to be in airports or urban centres.
Evidence:
1. read the link that Kodiak posted. One of a number of scientists who particpated in the IPCC but do not support its summary findings or policynprescriptions.
2. A link I have posted often enough before, I am getting sick of it (I will add it to my sig.) The Association of American Climatologists don't know what we are seeing either.
Policy Statement on Climate Variability and Change
So these people state that they cannot discern what they are witnessing from the information/data availble, but you can??

When I look at avaiable information I find myself agreeing with the stance of the skeptics (in 1 and 2 above).
Your second point. The models are not accepted. The GCMs used cannot even produce consistent results amongst themselves, they COMPLETELY ignore solar forcing (this is a BIG issue - again see Kodiak's link), They do not satifactorily account for feedback loops, in particular moisture and clowd cover. In short, these models are wildly unpredictable and poorly qualified to have any significant influence on policy decisions that could measurably effect our welfare.