The bathtub in question is the analogy Linda Booth Sweeney and John Sterman use to illustrate a dynamic stock-flow system, such as the relationship between greenhouse gas emissions (a flow) and the accumulation of greenhouse gases in the atmosphere (a stock). Gernot Wagner and Martin Weitzman stress the importance of the bathtub analogy in their new book, Climate Shock.Econospeak
What's fascinating about the bathtub analogy is how consistently people get the dynamics of accumulation wrong. Or at least how often business school graduate students with backgrounds in science, technology, math and economics get it wrong. Sterman has pioneered a cottage industry publishing articles dabout the inability of large numbers of students to correctly identify the effects of flow variations on stock levels. A frequent source of error is something Booth Sweeney and Sterman call "correlation heuristic": students often expect that changes in stock will have the same shape as changes in flow.
This common error has implications for people's attitudes about the action and policy needed to mitigate climate change, Booth Sweeney and Sterman point out. According to the correlation heuristic logic, many people would assume that a reduction in greenhouse gas emissions would directly translate into less greenhouse gas emissions in the atmosphere. It doesn't.....
Of Bathtubs, Bombshells and Boilerplate
Sandwichman
6 comments:
Students often expect that changes in stock will have the same shape as changes in flow.
I find the semantics confusing. As an engineering student I was trained to model "stocks" and "flows," but we used a different language -- math !
many people would assume that a reduction in greenhouse gas emissions would directly translate into less greenhouse gas emissions in the atmosphere.
It's important to note that we don't actually measure greenhouse gas emissions, it's merely an armchair estimate. Many types of emissions are not even included in the estimate -- i.e., arctic tundra thawing, Western wildfires, natural gas leaks. So I take the emissions estimate with a grain of salt.
There are statistical series that seriously, relentlessly correlate: energy consumption and hours of paid employment. ... Greenhouse gas emissions per hour of paid employment does not decline. .... To cut greenhouse gas emissions in half, we must cut hours of paid employment at least in half. ... the actual leverage point—voluntarily limiting our consumption—remains largely undiscussable
That is similar to the point I was debating with Auburn Parks a few weeks ago -- that if MMT could launch a massive Green New Deal, it would actually cause an increase in emissions, because there would be more activity and most of that activity produces emissions. I.e, it takes carbon to manufacture solar panels.
So I agree with Sandwichman's main point and I'm glad he said it so now I'm not the only one.
"There are statistical series that seriously, relentlessly correlate"
A bit like oil consumption and GDP.
Until it suddenly didn't because of a change in behaviour.
Another fallacy is the idea that things are locked in step forever. They are not.
Dan-
A short-term boost to emissions due to increased manufacturing and infrastructure activity (followed by the downstream consumer multiplier effects) in order to permanently transition away from fossil fuels is exactly what we should be doing. Unless you think the carbon problem is just going to take care of itself.
The carbon problem will take care of itself, just not within a timescale relative to human existence.
@Auburn, the budget that we should be focused on is the carbon budget. If we emit more than "X" amount of emissions then a tipping point will have been crossed and there is no going back.
The quantity "X" is debated and no one knows for sure. Or we may have ALREADY passed a tipping point, as evidenced by the unstoppable thawing of the poles and the melting permafrost.
It takes time to build green infrastructure and we may not have that much time, so I agree with Sandwichman that in the short run, the focus should be on reducing consumption. Rationing and a one child policy would be at the top of my agenda.
The low hanging fruit is conservation. It's the place to start, logically but not temporally. Temporally, a broad approach is required but the quick and easy gains can be reaped from conservation rather quickly. Other things aren't quite as simple to accomplish.
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