First, does invoking action actually change the coarse of climate change? According to Wiki “burden of proof falls on those who would advocate taking the action.” Thus those who advocate taking action to curb climate change need to show us that taking action will actually achieve the desired goal. It’s not like some potential new drug coming to the market where the company needs to show that it is safe. There is no action on the part of the advocates of caution there as they just prevent the drug from coming on to market. What the advocates of PP on climate change want is for positive actions to take place. This includes spending billions on things like the carbon trade system and billions more on carbon sequestering. Thus the burdon of proof then falls on them to show that these actions they propose will actually work, and not do more harm than good.
But will the reduction in our emissions of CO2 actually happen if we have a carbon trading system and carbon sequestering? Evidence will show that the answer to this question is no, and a very large no at that. With non-signatories China and India dramatically increasing their economies and energy consumption with it (China building coal fired plants as fast as they can) then any reductions in CO2 from the “developed” world will be swamped (within 10 years China’s energy consumption will be greater than the U.S.’s). Thus CO2 emissions will continue to rise, and not even the rate of emissions can be curtailed. Thus, realistically speaking, there is no way, short of society collapse, that CO2 emissions will slow let alone be reduced. (I even had one person tell me that even if the current changes in climate are natural, we should take action to “fix” it anyway!)
Second, what is the cost of the proposed actions? Does the cost of action out trump the “costs” of inaction? This is a comon sidestep by those who advocate action by saying the cost of inaction will be much more. Really? They can actually show evidence of that? The economy is so complex, so interdependant, that there is no way that such evidence can be shown. They may resort to models, but economic models are notorious for being grossly wrong, worse than climate models.
Besides, this only assumes the worst case scenarios of the alarmist positions on climate change. That in itself has not been shown to be a correct prediction of the future. Past warm periods, including the Medival Warm Period, was warmer than current predictions and was in fact not a catastrophy at all, but a boon to the biota. The two periods in the geological past that produced the vast majority of oil deposits were from times of much warmer climates. Thus to make the oil there must have been a much higher concentration of biota at those times. Thus, unless the alarmists can show why the current warm trend will be contrary to past warm events, then we can claim that such alarmism does not provide enough evidence to invoke the PP as a reason to act. In fact, the exact opposite.