agw - for thinkers not blind followers, page-8

Not many thinkers around it appears, perhaps the politics of climate change is easier to grasp than the science, or more interesting. But I think this is a relevant, and perhaps important question.
Does the greenhouse effect work primarily as a cooling mechanism, or a warming mechanism? Without greenhouse gases would the planet be boiling hot or bitterly cold?
I believe the answer is the latter. If that is the case then the benchmark that measures how effective the system is working must be the average minimum temperatures.
I believe this is important because the graphs that are used to depict changes in average mean temperatures show a different trend to graphs that depict the average minimum temperatures.
I started out looking for temperature data on the BOM site that was collected at sites in my region of rural Victoria. I was looking for sites that had recorded temperatures over a long period, but had changed little in terms of infrastructure over that time. This meant small towns or agricultural research stations where the heat island effect would be negligible. When I started comparing graphs of average highest temperatures, and average lowest temperatures, the difference in trends were obvious.

Perhaps others might like to do the exercise for themselves. Choose a site close to where you live, but away from big population centres. Many old towns have records going back 100 years, and some of those towns may not have changed much in that time. Indeed many of the buildings such as Post Offices may have been built in the 1800's as were the buildings surrounding them, thus apart from bitumen roads little has changed.
I would be interested to see what you discover.