The long answer is the subject of this post (and my book and this entire blog).
Certainly regular readers know that the nation and the world currently lack the political will to stabilize atmospheric concentrations of carbon dioxide at 450 ppm or even 550 ppm.
The political impossibility is also obvious from anyone familiar with Princeton’s “stabilization wedges” — and if you aren’t, you should be (technical paper here, less technical one here). The wedges are a valuable conceptual tool for showing the immense scale needed for the solution (although they have analytical flaws).
Of course, if solving the climate problem were politically possible today, I would have found something more useful to do with my time (as, I expect, would you). But 450 ppm or lower is certainly achievable from an economic and technological perspective. Indeed, that is the point of the wedges discussion (since they rely on existing technology) and the Conclusion to Hell and High Water.
The purpose of my last post on the adaptation trap was to make clear that 800 to 1000 ppm, which is where we are headed, is a catastrophe that is far beyond human imagining, that makes a mockery of the word “adaptation,” that has a “cost” far beyond that considered by any traditional economic cost-benefit analysis. It is both a rationally impossible and morally impossible choice. So, I think is 550 ppm, assuming we could stop there, which as I argued, we probably can’t thanks to the carbon cycle feedbacks like the melting tundra.
What needs to be done?
STABILIZING BELOW 450 PPM
[Note: I am going to do this entire post in billions of tons of carbon (GtC) even though I just wrote a long post explaining why carbon dioxide is better. That's because the wedges were formulated in GtC and are much more intuitive that way.]
As Princeton’s Robert Socolow and Stephen Pacala (S&P) explain:
A wedge represents an activity that reduces emissions to the atmosphere that starts at zero today and increases linearly until it accounts for 1 GtC/year of reduced carbon emissions in 50 years. It thus represents a cumulative total of 25 GtC of reduced emissions over 50 years.
They wrote their Science paper when we were at 7 GtC and rising slowly — an ancient time you may remember as 2003, before Bush was reelected, before anybody ever heard of Reverend Wright or Paris Hilton or the need to stabilize below 450 ppm. An innocent time, really, but I digress.
So they said that 7 wedges would keep emissions flat for 50 years and then, assuming we invested in a lot of R&D, we could start cutting global emissions rapidly after 2050, and stabilize at 500 ppm. And everybody would live happily ever after driving fuel cell cars, watching YouTube, and popping the occasional Xanax.
Problem 1: The world is at 8 GtC annual emissions.
Just to stabilize emissions at current levels thus requires adopting at least 8 wedges.
Problem 2: S&P assume “Our BAU [business as usual] simply continues the 1.5% annual carbon emissions growth of the past 30 years.” Oops! Since 2000, we’ve been rising at 3% per year (thank you, China). That means instead of BAU doubling to 16 GtC in 50 years, we would, absent the wedges, double in 25 years. That would mean each wedge needs to occur in half the time, assuming our current China-driven pace is the new norm (which is impossible to know, but I personally doubt it is).
Problem 3: A wedge is a mind-bogglingly large amount of “activity.” For instance, a post last year on the Keystone report explained that one nuclear wedge would require adding globally:
- an average of 14 plants each year for the next 50 years, while building an average of 7.4 plants a year to replace those that will be retired;
- Plus 10 Yucca Mountains to store the waste.
If you believe 3% growth is the new norm, then double that — 43 nukes a year for 25 years — for one wedge.
One wedge of coal with carbon capture and storage means storing the emissions from 800 large coal plants (4/5ths of all coal plants in 2000) — a flow of CO2 into the ground equal to the current flow of oil out of the ground. That’s right — you have to re-create the equivalent of the planet’s entire oil delivery infrastructure.
So one wedge from nuclear and one from CCS would be a stunning global achievement. Those who want to rule them out need 2 more wedges.
Here are other typical wedges (these are examples, not endorsements):
- If we built two million large (one megawatt) wind turbines, or 2000 GW. “Last year’s global wind power installations reached a record 20,000 MW, equivalent to 20 large-size 1 GW conventional power plants.” So we’re at half the rate needed for 1 wedge of wind (or mayber a quarter).
- If the fuel economy of the 2 billion or so cars in the world in 2050 got 60 mpg, that would be one wedge.
- For the conservation/peak oil folks, if the 2 billion cars in 2050 travel 5000 miles a year, rather than 10,000.
- If we grew biofuels requiring one-sixth of the world cropland.
- For S&P, ending all deforestation and doubling the current rate of tree planting is one wedge. In fact, if we don’t sharply reduce deforestation, we probably need to add another two wegdes (S&P used optimistic numbers for deforestation).
Problem 4: Stabiling emissions at current levels for 50 years and then declining sharply would probably not stabilize us below 600 ppm (even assuming that 1.5% annual growth was BAU, and not 3%).
For 450 ppm, we need to average 5 GtC this century. So we must be back down below 4 GtC globally by mid-century (and then head to zero by century’s end). Thus we need a minimum of 12 wedges if we started last year, which we didn’t. We probably won’t start putting serious measures into place before 2010 at the earliest, when we’ll be at 9 GtC. So that is 2 more wedges.
[Yes, I know, know, why in God's name did we elect and reelect two oil men who would spend their entire time in office not merely blocking all domestic action, but all international action, too. That is one for the history books, I'm afraid. What is especially depressing is that China's torrid love affair with coal plants only began after 2000, after it was clear the U.S. wouldn't take any action.... As Richard the III might have put it, a time machine, a time machine, my Kingdom for a time machine....]
Problem 5: The baseline of the wedges is unknown even to the the original authors, S&P. This is related to Problem 2.