In this post I will lay out “the solution” to global warming, focusing primarily on the 14 “stabilization wedges.”
Part 1 argued that stabilizing atmospheric concentrations of carbon dioxide at 450 ppm is not politically possible today, but that it is certainly achievable from an economic and technological perspective. It would require some 14 of Princeton’s “stabilization wedges” — strategies and/or technologies that over a period of a few decades each reduce global carbon emissions by one billion metric tons per year from projected levels (see technical paper here, less technical one here). The reason that we need twice as many wedges as Princeton’s Pacala and Socolow have said we need was explained in Part 1.
I agree with the IPCC, which concluded last year that “The range of stabilization levels assessed can be achieved by deployment of a portfolio of technologies that are currently available and those that are expected to be commercialised in coming decades.” The technologies they say can beat 450 ppm are here. Technology Review, one of the nation’s leading technology magazines, also argued in a cover story two years ago, “It’s Not Too Late,” that “Catastrophic climate change is not inevitable. We possess the technologies that could forestall global warming.”
I do believe only “one” solution exists in this sense — We must deploy every conceivable energy-efficient and low carbon technology that we have today as fast as we can. Princeton’s Pacala and Socolow proposed that this could be done over 50 years, but that is almost certainly too slow.
We’re at 30 billion tons of carbon dioxide emissions a year — rising 3.3% per year — and we have to average below 18 billion tons a year for the entire century if we’re going to stabilize at 450 ppm. We need to peak around 2015 to 2020 at the latest, then drop at least 60% by 2050 to 15 billion tons (4 billion tons of carbon), and then go to near zero net carbon emissions by 2100.
That’s why a sober guy like IPCC head Rajendra Pachauri, said in November: “If there’s no action before 2012, that’s too late. What we do in the next two to three years will determine our future. This is the defining moment.” Or as I told Technology Review, “The point is, whatever technology we’ve got now — that’s what we are stuck with to avoid catastrophic warming.”
If we could do the 14 wedges in four decades, we should be able to keep CO2 concentrations to under 450 ppm. If we could do them faster, concentrations could stay even lower. We’d probably need to do this by 2030 to have a shot at getting back to 350 this century. [And yes, like Princeton, I agree we need to do some R&D now to ensure a steady flow of technologies to make the even deeper emissions reductions needed in the second half of the century.]
I am not going to focus on the politics, policies, market factors, or mindset needed to achieve these 14 wedges. That will be the subject of Part 4. But, needless to say, none of this can happen without a serious price for carbon dioxide and a very aggressive technology deployment effort.
So here is the basic solution. I have thrown in a couple extra wedges since I have no doubt that everybody will find something objectionable in at least 2 of these wedges. This is what the entire planet must achieve: