Here is my succinct opinion about climate change variables:
1. CO2 levels have been rising due to fossil fuel combustion. This is a simple fact. Isotopic analysis shows most of the additional CO2 is from fossil fuels.
2. CO2 is a greenhouse gas. This also is a fact. The IR spectrum of CO2 shows this to be the case.
3. More greenhouse gases in the atmosphere COULD result in less radiative cooling, also a fact. At some point, the effect can be saturated and more doesn't mean higher Ts. We're not there yet.
4. The pure effect of this can be calculated, as a single variable, reliably, and is a couple tenths of a °C by 2100. E.g., the specific primary effect is pretty small.
5. There are however many secondary effects which is what climate folks try and model, forcing factors, like when ice melts the albedo decreases leading to more heating. This is very tricky and complex stuff and I'm not sure anyone has it right, but it is reasonable that the heating impact is greater than what is in Item 4 above.
6. If one accepts the IPCC estimates, the heating range will be 2-7°C by 2100, the upper limits of that being pretty catastrophic if it happens. There is some chance it is "misoverestimated" and will be more like 1°C which would be "OK".
7. There isn't much we can do to stop this technically. This is the hard reality of the story. A massive and expensive shift to nuclear power would have some impact, but isn't happening. Wind and solar will remain in the margins when you look at how much electricity we derived from fossil fuels globally. The rate of CO2 generation is going to continue to rise whether we sign agreements or not.
The one far out hope would be power from nuclear fusion that would be a game changer, but we "I" have no idea when that might become reality. Perhaps in 30 years fusion power could start to replace current power sources, optimistically. The current ITER experiment is somewhat promising, but there would be a lot of work even if they are successful.
Doing the lord's work there, and I just plain agree -- among the better summaries I've seen. My only point of contention, and it isn't really full-on, has to do with item number 7. You don't explicitly state that it's hopeless, but the spirit there does welcome that counterargument -- that there's not much we can do, "So why try?"
To which I always like to emphasize that being a good steward of the planet isn't just for tree huggers at Burning Man, it's for well-intending citizens and grandparents of every kind. From that perspective, the production of greenhouse gases isn't the only way we taint things. The same driving forces have volatilized the constituents of smog in several major cities, which appear to measurably lower human lifespan. And though not directly related, insufficient stewardship of a different kind has also facilitated a growing island of floating plastic the size of Texas in Pacific. And that's still without mentioning contamination (be it from hydrocarbons, heavy metals, radionuclides, etc.) of our limited groundwater, fisheries, lakes and so on.
We can do a lot better, and until we start to brush up against those realistic limits of "try," we definitely should.
Then again, in my experience, getting people to agree on this value of stewardship is not hard. The hardest parts are (1) depoliticizing it so that real talking is possible and (2) being humble/patient enough that the listener doesn't get turned away by chest thumping about "my facts" and authority.
When it comes down to it, that disconnect is the case for most controversial scientific conversations of our time -- also including evolution, stem cell therapies, vaccines and so on. Too many people with the most persuasive evidence available end up delivering it in a terribly arrogant and absolute way. I don't mean that as finger-pointing either. I know there've been many times when I've been at my wits end trying to convey scientific information (trying the right way) to an online audience but failed and wrote it all wrong.
Because those behaviors (humility, patience) that these discussions need most are two of the hardest behaviors to consistently exhibit.