Tyndall Center Director Anderson: Rapid Emissions Reduction Hard: 4-6C Far, Far Worse

[GliderGuider]

11. Both the article and the comments are deeply flawed IMO.

The assessment of our physical situation is realistic. The flaw is that everyone is talking about solutions while being utterly unrealistic about the potential.

The first comment following the article on Resilience.org says this:

We are going to emit enough GHGs by 2050 for at least 0.6C of further warming. Adding this to 0.7C of warming now timelagged "in the pipeline" of ocean thermal inertia, plus the 0.8C of warming already realized, would give 2.1C of warming as a total, but for one critical factor.

Ending our fossil fuel emissions means ending those of fossil sulphate which maintain the 'Sulphate Parasol' that veils the planet. As Hansen & Sato reported, the loss of the Sulphate Parasol will mean a rise of warming by 110%, (+/- 30%), raising the projected 2.1C to a total 4.41C (+/- 0.6C), that would be realized by about 2080 due the timelag of around 30 years after 2050. Our 'best case' for emissions control would thus give between 3.8C and 5.0C of warming.

However, there is a further critical factor, namely that of the interactive mega-feedbacks, of which at least six are already accelerating and several have the potential to dwarf anthropogenic GHG emissions. The most advanced of these, cryosphere decline (loss of snow & ice cover) causing albedo loss, is reportedly already causing warming equivalent to around 30% of our CO2 emissions. This feedback alone is already nearing the capacity to offset the 43% average annual intake of of our CO2 output by the natural carbon sinks.

From what I've read, this is a realistic assessment of the situation we are now in. There is no backing out of it, except for some small proportion of the 0.6C that will be brought about by our continued BAU emissions to 2050. Given the magnitude of the problem, the tiny difference that even draconian action would make, and the uncertainties involved, the only sure bet is that almost nothing will be done within the next 40 years. Politics and human nature will simply not support anything even remotely resembling a solution commensurate with the scale of the problem.

So we're looking at 3.8 to 5.0C of warming, even before the methane feedbacks get underway for real. When they do, we're looking at what - 6.0 to 10.0?

All this talk of solutions is hopeless twaddle. We're so done it's really not funny any more.