8 May 2013

Different paths to 20 by 2020

There are a LOT of initiatives to reduce x  (water, carbon, whatever) by 20 percent by 2020. Most of them are simultaneously ambitious ("unprecedented effort") at the same time as they are weak ("we intend to make good progress next year"), but what's interesting to me is how the path has a big impact on the eventual savings.*

Compare, for example, two paths to a 20 percent reduction:

The red path has no reduction for the first years, but then drops down to 80, a reduction of 20 percent by 2020. The blue path falls in the first years and then stays at 80 until 2020.

Against a baseline of do nothing by 2020, the cumulative "use of the resource" is down by 3 percent for the red line and 15 percent for the blue line.

So, the path does make a difference.**

Bottom Line: The next time someone says "next year," be sure to call them first on their potential laziness and second on the negative impact of that delay on cumulative resource use.

* I said four years ago that California could reduce (urban, agricultural) water use by 20 percent in a year by, respectively, raising urban water prices and using markets for allocating sustainable diversions of irrigation water. Neither reform has happened, and there's no sign of a reduction in demand. Call me when you want real change.

** Thanks to my lovely GF for this insight.