Thank you for the time you have spent identifying, documenting, and linking several climate change and energy elements. I wish to share some thoughts that I hope will engernder further discussion.
1). I agree the cheapest watt is the watt saved. EE should be aggressively pursued NOW.
2). We need to think in terms of delivered cost of watts and not only generated cost of watts. When watts travel there is loss, and we must build expensive transmission lines.
3). An honest accounting of the end-to-end costs of the energy supply chain would reveal there are many hidden costs and much collateral damage resulting from certain types of generation.
4). Some forms of generation are far more water intensive than others both in fuel extraction and in generation.
5). Many regions of the world are operating at severe water deficits and one should not assume the water will always be there for generation.
6).Generally RE has far fewer hidden costs and far less collateral damage. For example, the USA might not station the Fifth Fleet in Bahrain if it were not for the oil supply chain, and RE does not require mountain tops to be torn off that not only spoil the view but also the water supply.
7). The plan, site, build, commission, operate, and decommission cycle for generation plant may exceed 100 years. If we aggressively pursue EE we may be able to delay building some traditional generation while R&D on RE can drive down costs.
8) Electrcity storage has made great strides during the past 5 years and is poised to be ready for prime time this decade. Advanced Li battery power factors have increased an order of magnitude during the past 2 years, and a 5 minute vehicle charge is within sight.
9). Electrcity storage has been called a "game changer" by the Edison Electric Institute and can serve to smooth the demand curve, assist with frequency regulation, and solve the problem of intermittency associated with RE.
10). Yes natural gas is cleaner than coal by 50%--yet as global demand for electrcity doubles we wil be treading water if we over rely on NG.
11). We do not yet know even the unknowns associated with climate change and are only beginning to understand certain feedback systems. It would be dangerous to assume that it is a linear model--since it is a highly complex system the state-changes are more likely to occur rapidly fashion in a non-linear than incrementally.
12). Small changes in climate can have major impacts on human systems. A relatively modest climate change around 1320 brought unseasonal rains to England in the winter. The population had increased during the Medieval Optimum climate period and marginal land had been put into production. The resulting famine resulted in a 25% death rate and was followed 20 years later by the Black Death (and the Hunred Years War).
13). Our just-in-time agricultural system has been successful in reducing the % of people on the planet subjected to famine while reducing the number of days of food supply significantly. (I belive the most recent figure is 42 days of supply assuming efficient distribution). A relatively monor climate fluctuation could result in deep famine and rising prices especially in the developing world.
14). Famine historically destablishes governments and the bigger they are the harder they fall. Many dynastic changes in China can be traced to famine events.
15). You mention methane clathrates existing in ocean beds and in the tundra. CH4 also is being emitted in gaseous form from melting permafrost and rect studies suggest vast quantities exist beneath Artic Ocean ice (rapidly melting) and beneath Antarctcia. The permafrost belt extends across Siberia, Alaska, and Canada (not to mention Greenland) and the Yedoma region of Siberia (twice the size of Sweden) has seen millions of thermokarst lakes form within the period of satellite imagery--and many of these lakes have CH4 bubbling up out of them sufficient to prevent freezing in the winter.
16). CH4 release potential dwarfs human ghg emissions and has the appearances of a powerful positive feedback loop over which we have no control. It is extremely dangerous to take a wait-and-see approach with the permafrost as it might be a runaway train and could force a cliamte state-change. reducing anthropogenic ghg emissions can only slow the train down and might buy us time to adapt.
17). Yes humans have successfully adapted during the past severe ice age cycle and we live in most environments on the planet. Species survival is one thing--societal survival is another. Geneticists have observed several "bottlenecks" where human population was all but wiped out. A major volcanic eruption 70,000 ybp is perhaps the best example (Mt. Toba if I recall correctly). More recently the 17th century expansion of Sweden was terminated when famine prevailed for several years following eruption of a volcano in Iceland.
18). Assuming we might just squeak by without anthropogenci ghg's forcing a climate change we will cannot assume natural factors will not inconveniently occur.
In summary: Agressive Energy Efficiency NOW and Aggressive Renewable Energy R&D NOW. Through efficiency we buy time, and if we use the time wisely to drive down the cost of renewables we might just avoid a train wreck.
Thanks again for your post--I took the time to reply because of the high quality of work you shared.