Two weeks ago, British economist Nicolas Stern suggested the reasonableness of 350 ppm as a target for atmospheric CO2 if we hope to preserve the climate as we know it. It was the latest in a slew of commentary about 350 ppm, including support from IPCC chief Rajendra Pachauri.
This is a much sounder scientific and ecological goal than the 2007 IPCC assessment calling for 450 ppm. Mounting evidence suggest catastrophe is incipient. For some, it's already here.
NASA scientist James Hansen has been calling for 350 ppm for close to two years now, so Pachauri and Stern may be a little late to the party, but the flip side is that it may be a little early to celebrate.
To see why, it's worthwhile to remember why Stern used to call for 450 ppm — or even 500 ppm — as opposed to the 350ppm or lower level that many climatologists and ecologists now think is necessary in order to avert the cataclysm.
In his book, The Global Deal, published in 2009 — published in 2009 — Stern writes that a target of 400 ppm of CO2e, or less, is not only scientifically reasonable but probably ecologically necessary if we're to maintain betting odds of avoiding the deluge. However, such a target may be socially difficult. As he phrases it,
"To push hard for a lower target could disrupt the possibility of agreement in the very near future. It might look to some people like an abandonment or reversal of growth and development, and we risk appearing to ask for the impossible."
On this basis, Stern suggests an outline for a plan to hold atmospheric CO2e at 500 ppm and suggests cutting total emissions by 50 percent by 2050, with emissions peaking in 2020.
This would be fine. Except just pages earlier, Stern writes that the scientific arguments
"convince me that 500 ppm of CO2e with its high probability of exceeding 2ºC above pre-industrial levels (96%) and a 44% probability of being above 3ºC would indeed be a risky place to be. The problem with a target of 400 ppm CO2e is that we are already at 430 ppm CO2e (around 380 ppm CO2) and we are adding about 2.5 ppm per annum."
I could go on quoting Stern, but the surface tensions in this argument — and in his current statement that 350 ppm is a reasonable long-term goal — seem like outright contradictions, to the point that it's difficult to make sense of them.
If 350 ppm is a reasonable long-term goal, but stabilizing at 500 ppm CO2e is an economically reasonable short-long-term goal, how are we to move from 500 ppm to 350 ppm when there's a marked probability that warming will go above 2 degrees Celsius and a decent chance of global temperatures rising more than 3 degrees? It would be useless to belabor the point here—we all know that 2 degrees is the Rubicon.
So where does one go? And what's the broader point?
It's this: There's a chink in Stern's argumentation. That chink is in the clause that reads that pushing for the ecologically sane target and its attendant and sharp mandated reductions "might look to some people like an abandonment or reversal of growth and development."
We know that "development" for its own sake shouldn't be the ultimate target of economics — we need to discuss development's contribution to making human beings; the logical precursor to creating human beings is making sure the world is safe for them. Stern skips over that because it might look bad to "some people." Worse, it might appear "impossible." This should sound familiar to anyone listening to Congressional opponents of climate action.
There's no point in laboriously writing on the strangeness of a viewpoint which, when confronted with irreparable harm to nebulous concepts like "growth" or "development," or irreparable harm to the planetary environment that physically supports that growth and development, falls down on the side of avoiding irreparable harm to our economy of "growth" instead.
Stern must be aware of these tensions. In a just-published Guardian column, co-written with Tony Blair, the two call for, sequentially, a "green new deal," the possibilities of synergistic international cooperation, note that "The economic case for action on climate change is becoming ever more powerful," remind us that "Moreover, strong action on climate change will lay the foundations for a more sustainable, energy-secure future," and observe that "It should be obvious that all countries – developed and developing – should undertake the actions that are in their own economic interest, even if they require new capital investment to do so," e.g. from the capital-rich developed world, adding that "This is not an argument about transfer of resources, but about a sensible way to manage global risk and an investment in our economic health."
But not a word breathed about the necessity of 350 ppm as a hard maximum target, to be striven for immediately, nor a word about which will yield first: "growth" or ecology. There is also scarcely a word from them about the hard recognition of China and India's rights to development, dismissal of the notion of a "transfer of resources," an absolute necessity, and scarcely the barest mention of the fact that without a functioning planetary ecosystem, there is no growth, period.
Stern knows the science. Is there any reason he can't mention it?