Can't say as I see how 
, but suit yourself. You're pulling a bait and switch with the acidification remark. How high CO2 can go before the oceans become untenable for marine life is another topic entirely. The discussion is whether the planet is warming due to man-made influences. If that's not the scientific problem, then quit talking about GW and let's talk instead about acidification.
It's not a bait and switch at all. It was a direct response to your claim that we should weigh the alternative of reducing warming in ways other than CO2 reduction...
The percent certainty is important in determining if it is more cost effective to attempt to reduce CO2 (and hopefully but not certainly) slowing warming, take other proposed measures to counter-act warming, or instead to mitigate it's effects.
...Because that misses the point that increasing atmospheric CO2 has other negative impacts that go beyond average temperature. If that were not the case, then you would be right that we could apply a more traditional cost/benefit calculus to the correct course of action.
I understand that the point goes beyond global warming, but that's also why the term "climate change" is preferable. The ocean is just as important to our climate as the air we breathe.
It's a good one..... but it requires a little thinking.
The person I quoted said that GW was a possibility so we should do something about it now.
I asked this question of him.... not you..... to see if he did the same in his daily life. His vehicle could break down at any time. Was he prepared. It could be catastropic for him and his family if he was not.
No, your analogy is crap, but I will answer it anyway. I have a jack and a spare (oh wait, also have some flares, water, flashlight, quart of oil). If anything goes wrong beyond that, I have AAA...because hey, it's not like the sea level's rising or something.
