Global warming of +10C is ====>!!NOT!!<==== a reasonable expectation (erratum et apologia)

[CRH]

8. I think your study has a weakness that you have stated, ...

in the third to last paragraph of your post.

If we indeed do reach 4*C by mid century I feel this will greatly limit our ability to maintain the social and industrial order necessary, to rapidly burn off the rest of the hydrocarbons in the last half of the century. Therefore, what we already have baked in the CO2 concentration mix, will be about it. What is the planet's sensitivity to doubling CO2, who knows? But what we have seen at just .8*C rise, are undeniable feedbacks much ahead of the IPCC models' schedule.

Hurricane Sandy, before that Katrina and others, already show large disruption in large cities and commerce. 2011 and 2012 saw major drought on five continents, and subsequent crop failures. The Arctic ice melt guarantees continued and larger disruption of sea and atmospheric currents, leaving weather models useless for planning agriculture. This is all happening at .8*C.

At 2*C there will be far more disruption, and in addition almost certain fresh water restraints. Will these disruptions be linear in proportion, or exponential? At 4*C I think we will be very lucky to have much order remaining, starvation and nomadic migration will add stresses of their own. At this point I foresee industrial output chaotic at best, limited by the abilities of consumers as well as water and power considerations. There will still be plenty of hydrocarbons for power production, but I question seriously if the infrastructure and social order will remain at levels needed to continue rising production.

In short, I don't think it likely we have at our means the innovation necessary to adapt to 2*C then 4*C in an already faltering economy, climate, and society. On a global level, that would take cooperation and sharing of resource and intellectual property. Hasn't happened in the last 5,000 years, and I don't expect it to start now.

I also think anything more than 4*C is moot in the long run, as that bakes in 6*C minimum with chances of unknown feedbacks as well. And I don't agree with some that believe anywhere beyond 4*C is adaptable. It is easy to say PETM was survivable to most mammalian species, at 6*C, but how many died, how far did they have to migrate, and were they as fragile as humans in cold and warm conditions? What were the conditions of the earth before, PETM, pristine? What other land mammals except humans have depended on the oceans for a large amount of their sustenance? No, I can't image much above 4*C as survivable, with the variance in heat conditions in different latitudes.

Just a few of my thoughts. hrh