agree with everything except the last sentence.
If you do a weighted cost benefit analysis.
For example lets say that global warming has a 10% chance of happening, and if it happens at the rate predicted it will cost 5,000 dollars in damage. Not using real numbers. Lets say investing in new technology will cost us 1,000 and has a 80% chance of saving us.
Do nothing
10% * 20,000 = 2,000
Invest and does not work
1,000 + (10% * 20% * 20,000) = 1,400
Invest and saves us
1,000
Working on the assumption that it is 20X more expensive to loose the majority of the coast line, famine, hurricanes, etc. than to invest in technologies that can stop and reverse global warming. Global warming might just be a small change in our generation, it is the generations to come that will have the real problem.