Open hdrake opened 2 years ago
Note: this example requires making some small changes to the diagnostic functions to make cost exponents a keyword argument. See branch https://github.com/ClimateMARGO/ClimateMARGO.jl/tree/multiple-equilibria
@CommonClimate, this is somewhat related to questions you had about exploring multiple policy equilibria. In this case I've gotten here by modifying the economic functions, but you could also introduce multiple equilibria through non-linear physics.
Interesting. I'll take a look later this semester when I prepare that lab. Thanks for keeping that question in mind!
I came up with a simple example of multiple equilibria, which could be used to test the limits of optimization schemes (cc @danielkoll). All I had to do was decrease the exponent of the control costs (here for geoengineering and mitigation) to below p=1, which can be thought of as a crude parameterization for "economies of scale" or "learning rates". This is because marginal costs scale like p-1 and thus decrease with more deployment and so it makes more sense to put all of your eggs in one basket. In this example I tuned the parameters so that it happens that the two local minima are roughly similar, so that there are two roughly equivalent policy options.
Here is a minimal example to reproduce the plot.