Don't just do something, stand there! Reflections on the counterintuitive behavior of complex systems, seen through the eyes of System Dynamics, Systems Thinking and simulation.
I recently discovered a cool set of tools from MIT’s Simile project. My favorites are Timeline and Exhibit, which provide a fairly easy way to create web sites where visitors can interact with data. As a test, I built an Exhibit containing Richard Tol’s survey of assessments of the social cost of carbon (SCC):
From the latest National Journal‘s Congressional Insiders Poll. Perhaps this is another special case of the general phenomenon of elites being more politically polarized.
The history of long term energy forecasting is a rather mixed bag. Supply and demand forecasts have generally been half decent, in terms of percent error, but that’s primarily because GDP growth is steady, energy intensity is price-inelastic, and there’s a lot of momentum in energy consuming and producing capital. Energy price forecasts, on the other hand, have generally been terrible. Consider the Delphi panel forecasts conducted by the CEC:
In 1988, John Sterman showed that energy forecasts, even those using sophisticated models, were well represented by a simple adaptive rule: Continue reading “More Oil Price Forecasts”
The Climate Change Science Program web site has the newly-released Scientific Assessment of the Effects of Global Change on the United States frontpage, along with a Revised Research Plan for the CCSP.
Recently Pielke, Wigley and Green discussed the implications of autonomous energy efficiency improvements (AEEI) in IPCC scenarios, provoking many replies. Some found the hubbub around the issue surprising, because the assumptions concerned were well known, at least to modelers. I was among the surprised, but sometimes the obvious needs to be restated loud and clear. I believe that there are several bigger elephants in the room that deserve such treatment. AEEI is important, as are other hotly debated SRES choices like PPP vs. MEX, but at the end of the day, these are just parameter choices. In complex systems parameter uncertainty generally plays second fiddle to structural uncertainty. Integrated assessment models (IAMs) as a group frequently employ similar methods, e.g., dynamic general equilibrium, and leave crucial structural assumptions untested. I find it strange that the hottest debates surround biogeophysical models, which are actually much better grounded in physical principles, when socio-economic modeling is so uncertain.
Nature News and Climate Feedback report that cooling of sea surface temperatures ca. 1945 is an artifact of changes in measurement technology. ClimateAudit claims priority. Lucia comments.
Will this – like the satellite temperature trend – be another case of model-data discrepancies resolved in favor of the models?
Update: Prometheus wonders if this changes IPCC conclusions.
One observation from my recent experience with climate policy in California is that businesses – even energy intensive ones – are uncertain how to engage in the public debate. Climate policy is a messy space with many competing options, and it’s hard to know what to wish for. With that in mind, here’s a quick survey of what various business groups are saying.
Every year or two the “gas out” email arrives in my inbox. This year, it’s May 15th when “all internet users are to not go to a gas station in protest of high gas prices.” Wait – am I supposed to avoid gas stations, or protesting at gas stations? I’m amazed at the durability of this internet chain letter, which now claims a ten-year history: “In April 1997, there was a “gas out” conducted nationwide in protest of gas prices. Gasoline prices dropped 30 cents a gallon overnight.” A Monty Python tune from The Meaning of Life jumps to mind:
So remember when you’re feeling very small and insecure
How amazingly unlikely is your birth
And pray that there’s intelligent life somewhere up in space
Because there’s bugger all down here on earth.
The NYT reports that a switch to efficient cars is underway, as evidenced by, among other things, an increase in market share for small cars from an eighth of the market at the height of SUV-mania to a fifth today, together with a sharp drop in large truck and SUV sales.
If sustained, such a shift would signal a very significant sensitivity of vehicle efficiency purchasing habits to fuel prices – perhaps much larger than the low short run price elasticity of gasoline demand. However, I think there is reason to interpret these recent events cautiously, lest they prove a little less astonishing in the long run. Continue reading “The Switch to Small Cars – Not So Fast”
DeSmogBlog documents scientists’ outrage at inclusion on Dennis Avery’s list of 500 Scientists with Documented Doubts of Man-Made Global Warming Scares. Amusingly, the scientists concerned, a few of whom are deceased, are listed as “Co-Authors”. I’m going to put this new “open coauthoring” concept to work – I’m already working on abstracts. First, I think I’ll lower my Erdős number – Paul, dude, you can be my second. Next, I think I’ll team up with Einstein and Bohr to finish up quantum gravity.