Climate Signals - New York Times

In an editorial this morning (Climate Signals - New York Times), the NYT suggests that perhaps the strength of the link between the carbon cycle and international politics is strengtheing....

Earth System (singluar)

Imagine a surface of constant, but very low, nitrogen concentration that encloses Earth. That surface is closed and it bounds the Earth System.

While that surface is closed, it does not mean that there are no fluxes across it. Mass crosses in both direction: incoming mass includes meteorites, but also, depending on what nitrogen concentration is chosen to define the surface, a selection of space junk; outgoing includes helium and space probes. The energy balance across that surface determines, among other things, Earth's room temperature.

The scale of that surface defines the largest scale in the hierarchy of Earth systems. The fluxes across that surface connect the Earth System to the Solar System and other systems beyond. That is clearly a loose coupling, but it is just the sort of thing that allows a hierarchical scale to be defined.

Within the Earth System, there are many subsystems. Those subsystems include the carbon cycle, international economics, my body and the computer on which these ideas are being composed. Many of those subsystems are linked and the links between them can be stronger or weaker. The link between the carbon cycle and international economics is reasonably strong; for better or worse the link between the carbon cycle and international politics is weaker than that with economics.

Our challenge then is to work out the connections and workings of subsystems of the Earth System and in so doing find levers we can pull to ensure that the possible futures for our planet include a reasonably large set that are satisficing.

Sustainability as Satisficing

I would like to propose yet another definition, or perspective anyway, for the idea of sustainability. The classical definition of the Bruntland report suggests that sustainability is a state of meeting the needs of today without sacrificing the needs of the future. Joel Cohen has pointed out that the Bruntland definition assumes that we have some idea of what the needs and capacities of the future will be, which we don't. He introduces a more dynamic notion of sustainability that incorporates changing needs and abilities.

Both the Bruntland and Cohen approaches to sustainability bring our responsibility to future generations into the picture. This is important and they do it through an emphasis of the future and on an implied sense that if we are good then we might achieve sustainabilty sometime in the future.

I would like to propose that we move our sustainability focus closer to the present. In particular, I propose the following:

Sustainability is the existence at any given time of a set of possible futures which are acceptable in some satisficing sense.

Central to this recasting is the idea that sustainability is something that we have or don't have at the moment. My definition does a couple of other things:

• It recognizes that decisions that we make today, determine what is possible and what is not possible as we move forward.
• It introduces the notion that sustainability is not optimizing, but satisficing and through that notion brings ideas of bounded rationality to bear on our discussions of Earth management.
• By introducing ideas related to administration and organizations, it introduces the idea that sustainability is a management problem.
• By focusing on the present, it recognizes that there are some messes that we are simply going to have to deal with (an ice free Arctic for example).
  

The notion of an evolving set of satisficing possible futures is central. It does not imply futures are given, but that they are created. The need to steer toward desired possible futures will illuminate priorities with respect to resource allocations.

For instance, I expect that Earth will burn a lot of coal in the coming century. There is a possible future where this happens and we avoid acidification of the oceans, but that future requires the development of technologies to suck CO2 out of the atmosphere. CO2 sucking technologies are also possible both theoretically and economically. I think we should decide to develop such techologies so that the possible future of cheap energy for economic development along with continued functioning of surface ocean ecosystems is attained.