Here are two simple rules to keep in mind that will help us, perhaps, to avoid being unduly influenced by one side or the other:
1. No one who is not a climatologist or practices in a field closely related to climatology is unlikely to possess any particular expertise in climate change and his or her testimony should not be taken as dispositive.
2. Of the arguments made by those scientists who are qualified to speak with authority we should be suspicious of the testimony of anyone who is funded by either progressive organizations, the government, or corporations which themselves pump greenhouse gasses into the atmosphere. In other words, we should be prima facie skeptical of any argument made by any scientist who is paid by any organization which has a financial or political stake in the outcome of the debate.
Having said that, I offer here three questions I myself would like to see conclusively answered by independent climate scientists:
1. Is the climate definitively changing in a significant way?
2. If it is, is human activity definitely responsible?
3. Whether human activity is responsible or not, is the change certain to be a bad thing?
I have some thoughts on these three questions, but I certainly don't have any answers, and I'm not a climate scientist, so even if I did offer answers you shouldn't pay them any special heed, or any heed at all. The thoughts, however, are thoughts you might have as well:
Regarding question #1: When I was in Alaska I was shown compelling evidence that glaciers have been retreating over the last century, so I'm persuaded that something seems to be going on. On the other hand, despite predictions to the contrary, there's data to support the claim that there's been no significant increase in mean global temperatures over the last twenty years, and considered over the last couple of thousand years today's temperature fluctuations do not appear unusual (see chart below). Moreover, predictions a decade ago that the polar ice sheets would be diminishing have not, as far as I'm aware, been fulfilled. Nor have predictions of massive storms, increased numbers and ferocity of hurricanes, etc. come to pass. In fact, it seems to have been quite the opposite. So whatever is happening, whatever's causing the glaciers to retreat, seems, at least to me, to be very unclear.
Regarding question #2: The current thinking is that by pumping greenhouse gases like CO2 into the atmosphere we're inevitably creating conditions for runaway warming, but there are so many variables and unknowns that it's hard to say what effect our increase of atmospheric carbon is having. We don't know (or do we?) to what extent the biosphere (green plants) assimilate the extra carbon. Nor do we know what effect carbon has on the amount of water vapor in the atmosphere. An increase in water vapor could increase cloud cover which would result in more solar heat reflected back into space. Moreover, if the earth's climate is changing it's not clear whether the change is caused by greenhouse gasses or by variations in solar activity. Maybe I'm wrong and all those phenomena are actually well understood, but if so that knowledge has not been widely shared with the lay public. It isn't enough for scientists and politicians to urge us to just trust them. They have to give us facts.
Regarding question #3: Plants use CO2 to make nutrients. Increasing atmospheric CO2 (within limits) might produce greater crop yields, which would be a good thing. Furthermore, some warming could produce longer growing seasons. If the polar ice melted that could open up vast stretches of land (in Greenland and Siberia, for example) for mining, agriculture, and human habitation. Too much warming would surely have calamitous effects, but, moderate warming could be, on balance, a boon to humanity. We just don't know. Or at least I don't know, and I wish those who do know would make it more clear.
Because I have these questions and haven't encountered any definitive answers I remain dubious that global climate treaties, President Obama's war on coal, and talk of carbon taxes, etc are actually necessary, and since I'm very skeptical of the wisdom of giving government even more power than it already has I want to see more solid data that shows that the globe really is warming, that the warming really is caused by human activity, and that it really is a bad thing before I support policies that would put thousands, maybe tens of thousands, of people out of work and be potentially ruinous to the economic well-being of the country.
So far, the data supporting the conclusion that the climate is changing in potentially catastrophic ways, at least that I've seen, have not been incontrovertible, nor conclusive, and thus not very convincing. I'm certainly willing to be convinced, however, if someone can show me substantial and indisputable evidence that we really are on a collision course with disaster.