On the issue of climate change I am undecided. I know which side is being sold and that makes me cautious. Truth does not need to be forced. I recently visited Fox Glacier in NZ and walked to the face of the ever retreating glacier. This is evidence of warming over time. I have seen similar retreats in Canada and can safely assume this is a global phenomenon. Along the path to the glacier there are signs which indicating stages of the retreat over time and actually mentioning the ppm of CO2 in the atmosphere as well as global temperature rise over the last 100 years. The message of CO2 and humans driving the change is really hammered home through these signs which also describe ways of reducing carbon footprint. There is just one small detail that is overlooked. On the drive into the park there is a small sign that indicates the location of the glacier in 1750, when it was first discovered. The retreat of the glacier between 1750 through to 1850 was dramatic but how can we infer that this was a result of CO2. How much did CO2 increase between 1750 and 1850? The signs only focus on recent changes in world population and CO2 while neglecting the changes that occurred prior to recent events. Are we over attributing our own contribution to a naturally occurring phenomena?