Now, let me first say that I believe that the Earth is warming. Second, let me be very clear that humans are not the sole cause for it; and here is why I believe this:
Although there are many theories and computer models that predict catastrophe based on the data supplied, the models are not perfect, and they don't include every variable involved. These models are based on our current understanding of the climate, which is not total. We are learning more every day, and as we do, those models are being changed. Have you noticed how notoriously bad your local weather forecast has become over the last few years? That's because they switched models, and although those models included more variables, they were prone to be wrong more often because the information fed into them was either inaccurate or the model was not calibrated properly. The same happens with global climate modeling.
Again, I do believe that the climate is warming, but I believe it is 99% due to natural cycle and 1% due to human activities (rough estimate of percentages). Why do I believe this? Because of several things:
