HourglassPhoto: Xava duCross-posted from Real Climate Economics.

The elections earlier this month saw the breaching of the 2016 deadline set by NASA’s Jim Hansen for global CO2 stabilization, and also moved us well beyond IPCC Chair Rajendra Pauchuari’s statement that action beyond 2012 “will be too late“. So where does this leave us? For what are we now, officially, too late? 

Until this year, one could envision, just barely, a “politics-as-usual” scenario that set us on track to stabilizing C02 concentrations at 450 parts per million (ppm). The 450 goal would, according to the IPCC’s best guess, have held global temperatures to 2.1 degrees C (3.78 degrees F) above pre-industrial levels — a further 1.5 degrees C (2.7 degrees F) warming this century. Getting there would have required U.S. policy that initiated cuts in 2012, and delivered 80 percent reductions by 2050. These would have had to have been coupled with Chinese and Indian commitments to stabilize emissions by 2025, and then start down their own aggressive emission reduction pathways.

The 450 ppm goal could have been accommodated by (ambitious) politics-as-usual, because nothing radical, or particularly costly, was required. Instead, a gradual ratcheting down of fossil fuel consumption, coupled with policies to promote the rapid spread of efficiency and renewables, could have, more or less seamlessly, gotten us to 2050 and the 450 ppm goal. Up until this year, the challenge was neither technical nor economic, but rather political. And, at least in the U.S., we were almost there. Had Ted Kennedy not died, I think we would have had first-step climate legislation in place last April.

Now, with U.S. policy stalled for six to 10 years, 450 ppm is simply off the table under politics-as-usual. It is still within reach assuming extraordinary politics post 2020: a World War II style mobilization to rapidly rewire of the world with clean energy. It may still be achievable via the unforeseen development of truly cheap solar cells. But barring those two developments, toward what ambitious goal are we now realistically working?

The IPCC’s B1 scenario is still, just barely, on the politics-as-usual table. B1 has a CO2 equivalent of 600 ppm, implying CO2 concentrations of perhaps 550, and would lead to a 2100 temperature increase of, IPCC’s best guess, 2.3 degrees C (4.14 degrees F) above pre-industrial, or a further 1.7 degrees C (3 degrees F) this century. In contrast to the 450 scenario, B1 allows global emission increases by 2050 to 40 percent above 1990 levels, giving us a little wiggle room. But just a little. While European emissions have stabilized around 1990 levels, the U.S. has already eaten up close to half of that space.

At first blush, B1 doesn’t seem so bad: only a .2 degree C (.36 degree F) temperature increase over this century from the 450 ppm target. But unlike the case of 450 stabilization, global temperatures would keep rising significantly beyond 2100, unless our grandkids can figure out a way to dial back the CO2 concentrations, to 450, 400, or even 350. And of course, every tenth of a degree matters, because of the possibility that we may cross some biophysical tipping point — methane releases from thawing permafrost, fire-driven deforestation — that would cause even further warming.

At second blush, following November’s elections, something like B1 is now the best we will do under ambitious politics-as-usual. Folks dedicated to stopping global warming — so-called climate hawks — need to understand that, short of climate-disaster-driven politics, or unforeseen economic break-throughs, the likely best-case-scenario is that the road to 350 will go through 550. 

That said, B1 won’t happen without extraordinary dedication to the current political process, and the rebuilding of a powerful, inclusive clean-energy movement over the next two years, and the next decade. Pre-recession, global emissions growth exceeded the IPCC’s high end scenario, A1F1, a nightmarish 1550 C02 equivalent scenario by 2100. So while our current political system could deliver B1 as an alternative, it simply will not, without the kind of widespread political engagement that goes beyond what we saw with the Obama phenomenon in 2007-2008: sustained, focused on clean energy, and occurring in a less disastrous economic environment.  

How does this “climate-realist” road go?

  1. For the next 6-10 years, the Clean Air Act, California’s policies, RGGI, and other laws can be used to hold U.S. emissions steady, and maybe even cut them 5-15 percent. This means fight like hell to keep the policies strong. In 2012, the presidency, not Congress, will be the key, in determining the speed at which the EPA moves forwards.
  2. In the meantime, rebuild a grassroots political movement demanding clean energy. Support all efforts at the state and local level, and work all levers to drive investment into clean energy.
  3. By 2016 or 18, or even 20, rebuild super-majority congressional support for clean energy, and pass comprehensive carbon legislation. The timing will depend on the degree to which climate disasters unfold.

So we stabilize as low as we can, and then leave it to our kids and theirs to then drive levels back to 450, and within a century or two, back to 350. Hope and pray that all our combined work catalyzes some cheap clean technology, that solves the problem in ways we can’t imagine, and sooner than we ever thought possible. And hope and pray also that we don’t cross tipping points along the way, triggering runway warming in the process.

For those of us who have been, for many years, working toward a 450 or even 350 goal for this century, the elections this month have created a harsh new reality, a profoundly depressing reality. Yet we all still know that keeping the CO2 blanket as thin as we possibly can will preserve a dramatically more livable world, and will protect many more of the beautiful creatures of this earth, than will a blanket of 650, or 850 or 1000 ppm.

In our lifetimes, it will never be too late to fight global warming. Every degree will matter. Over the coming years and decades, there will be no better fight, no victory that will more enrich the lives of countless human generations to follow, than to stabilize the climate.