Month: June 2012

Minds are like parachutes, or are they dumpsters?

Open Minds has yet another post in a long series demolishing bizarre views of climate skeptics, particularly those from WattsUpWithThat. Several of the targets are nice violations of conservation laws and bathtub dynamics. For example, how can you believe that the ocean is the source of rising atmospheric CO2, when atmospheric CO2 increases by less than human emissions and ocean CO2 is also rising?

The alarming thing about this is that, if I squint and forget that I know anything about dynamics, some of the rubbish sounds like science. For example,

The prevailing paradigm simply does not make sense from a stochastic systems point of view – it is essentially self-refuting. A very low bandwidth system, such as it demands, would not be able to have maintained CO2 levels in a tight band during the pre-industrial era and then suddenly started accumulating our inputs. It would have been driven by random events into a random walk with dispersion increasing as the square root of time. I have been aware of this disconnect for some time. When I found the glaringly evident temperature to CO2 derivative relationship, I knew I had found proof. It just does not make any sense otherwise. Temperature drives atmospheric CO2, and human inputs are negligible. Case closed.

I suspect that a lot of people would have trouble distinguishing this foolishness from sense. In fact, it’s tough to precisely articulate what’s wrong with this statement, because it falls so far short of a runnable model specification. I also suspect that I would have trouble distinguishing similar foolishness from sense in some other field, say biochemistry, if I were unfamiliar with the content and jargon.

This reinforces my conviction that words are inadequate for discussing complex, quantitative problems. Verbal descriptions of dynamic mental models hide all kinds of inconsistencies and are generally impossible to reliably test and refute. If you don’t have a formal model, you’ve brought a knife, or maybe a banana, to a gunfight.

There are two remedies for this. We need more formal mathematical model literacy, and more humility about mental models and verbal arguments.

Computational gains in complex modeling

Interesting approaches to crowd simulation by abstracting agents to fluid fields (around 6:20), and model reduction for fast simulation of high-dimensional fluid problems (around 23:00) and realtime control (33:00):

I haven’t really digested the implications of this, but it’s interesting to consider what the implications might be for simulating lumpier systems, like traditional SD or economic models, where model reduction has not been very widespread, or for large-scale computing like climate models.

Reading between the lines

… on another incoherent Breakthrough editorial:

The Creative Destruction of Climate Economics

In the 70 years that have passed since Joseph Schumpeter coined the term “creative destruction,” economists have struggled awkwardly with how to think about growth and innovation. Born of the low-growth agricultural economies of 18th Century Europe, the dismal science to this day remains focused on the question of how to most efficiently distribute scarce resources, not on how to create new ones — this despite two centuries of rapid economic growth driven by disruptive technologies, from the steam engine to electricity to the Internet.

Perhaps the authors should consult the two million references on Google scholar to endogenous growth and endogenous technology, or read some Marx. Continue reading “Reading between the lines”