I can agree on some common ground, I think it is important to evaluate the evidence and carefully weigh costs and benefits of any action. With that being said, I think there is significant evidence of rising temperatures and changing weather patterns, and consequently there are three different categories of actions people should be considering: adapting to the changes that are already here and are going to be here in the near future; limiting greenhouse gasses to reduce long-term changes; and finally, carefully consider some geoengineering solutions as a counter to man-made greenhouse gasses that are already released.

To me, the first category is the easiest, most obvious thing we should be doing. Consider the fact that Florida state officials are banned from using the words "climate change," "global warming," or "sustainability;" that is the kind of pants on head behavior that should change. The Republican debate last night (unsurprisingly) didn't even mention global warming. Coastal cities need to be looking at maps of sea level rise predictions to discourage development in the most vulnerable places, and increase infrastructure development in areas that are the least vulnerable. The California drought is another event where changing weather patterns could mean that the drought just doesn't end, and unless new sources of water can be found, the public needs to change water consumption patterns. Obviously the third world is going to have to adapt too, and their challenges are much greater, but I'm not sure what you mean by your question of what "the present, urgent problem" is. Eventually every community on the planet will be faced with present, urgent problems that need to be addressed, and understanding what those problems will be sooner rather than later will make adapting to them much easier.

The second category, limiting GHGs is probably more controversial. Personally, from what I've seen and read, I'm fairly convinced that anthropogenic GHGs are significant driving factor in the global warming phenomenon. To be sure, the climate system is very complex, it's not the only factor, and perhaps, we have crossed a threshold where other feedback loops have taken over and it's no longer the primary driving factor; however, to the extent that reducing human-emitted GHGs can positively affect global warming, I think we really need to make an effort there, even if it is costly.

Speaking as someone from the United States, which emits one of the highest quantities of GHGs per capita, I'm of the opinion this is an issue we should be leading on, not dragging our feet. Furthermore, how could we expect other developing nations to believe that you can have a high-quality of life and industrial development without a massive carbon footprint if we can't even do it here? Is it unfair that everyone on the Indian subcontinent can't have a coal-powered AC unit? Yeah, but I'll be the first to admit, the great injustice was that the western world has spent the last hundred plus years burning fossil fuels with furious abandon, providing us with inexpensive energy and a high quality of life, pushing the costs onto the rest of the planet and future generations. My parents and grandparents are guilty of this (even if perhaps unknowingly), and I'm guilty of enjoying its benefits, but the appropriate course of action is not to perpetuate this inequality.

Of course, anything we do about GHGs has to be tempered with a cost benefit analysis. I'm assuming (and correct me if I'm wrong) that you're unconvinced anthropogenic GHGs are a driving factor in global warming, which would give you a very low bar for any benefit to reductions in GHGs. What do you think alternative driving factors could be? I know you mentioned increased volcanism, which I'll admit, I did some brief research into and I'm not sure I really came away convinced that there was a significant causative link there, perhaps I'm missing something. I've also heard changes in solar radiation bandied about, although again, I haven't seen much evidence indicating that's the case. As I've said, I'm a layperson who can easily be manipulated or misled (coupled with the fact that this is a highly politicized issue with many groups seeking to maintain profits by explicitly misleading people), and I recognize that, so I'm open to the idea that maybe I'm wrong; perhaps you can instill me with some of your doubt and my perspective will change. I look at the worst-case scenarios (obviously not likely, but still a possibility worth considering), where there is multi-meter sea level rise, extinction of the majority of ocean species and significant proportion of land species, and if we have the possibility of mitigating some of that, it's a very big benefit, worth a high price.

The third category of actions is a little more tenuous I think, and should reserved for if it becomes clear we're going to have a Permian extinction level event. My fear is that by the time it's apparent that's happening and we all agree on that, anything we're capable of in the geoengineering category will be too little too late, so perhaps we've already sealed our fate here. Anything we do here would likely be expensive and risky, but I still think it prudent to actively research what could be the cheapest and easiest methods to reduce carbon dioxide concentrations in the atmosphere. Methane, from what I understand, breaks down much faster, so perhaps there is less we need to actively do about that, but plans of action and their cost/benefit analysis is best left to scientists who have a much better grasp of what's happening.

In conclusion, I'll say that nobody wants to "pay more for energy," obviously. Modern civilization is predicated on cheap energy, and it certainly is very unfair that the western world got fat on fossil fuels while the true costs were hidden for a century. To me, the prudent choice is to (through research and evidence) make clear what the true costs of fossil fuel usage are for the ecosystem and pursue a new economic model that accounts for that. If the developing world doesn't want to be a part of a new paradigm, I can't say that I blame them given their position, but humanity's future should be in their hands; the western world has already blindly failed on this issue for the last century. Everyone will feel the pain of global warming, the only thing we can do is reduce our footprint, prepare and adapt.

Would you know if you were wrong? Could you make measurable predictions now that someone could check five, ten, or more years from now to see if your concerns today are justified?

So do I. It's one of my worst fears - that civilization would not end incinerated by a nuclear flash, but slow-cooked by it's own carelessness.

But there's very little we can do but wait and hope for the best.

Yeah, that was a big skepticism fail on my part.