I would argue that the data doesn't go back hundreds of years, and that only remotely solid data only goes back 40 years. Automated systems for data gathering have really only widely been available for the past 20 years and economically feasible for mass distribution for the past 10 years.
That said i'm not arguing at all against human caused global warming, just posting data that screams the sky is falling. My stance is that doing anything to try to affect the rate of warming at this point is a drop in the pond. All the green initiative here in the states is just nothing to what china and india are doing to the climate, and as Africa experiences a rapid and explosive industrialization over the next 50 years we will be even more negligible. Money better spent would be on relocating people from areas that will either be flooded or protecting low lying areas as water levels rise.
Additionally, what if we are wrong and there is some other forcing that is driving climate change? Then all of this time and money that could have been spent on preparing for the worst would have been wasted on trying to prevent it.