Next Generation Climate Policy Models

Today I’m presenting a talk at an ECF workshop, Towards the next generation of climate policy models. The workshop’s in Berlin, but I’m staying in Montana, so my carbon footprint is minimal for this one (just wait until next month …). My slides are here: Towards Next Generation Climate Policy Models.

I created a set of links to supporting materials on del.icio.us.

Update Workshop materials are now on a web site here.

California Punting on Cap & Trade

Bloomberg reports that California’s cap and trade program may still be some way off:

[CARB chair] Nichols told venture capitalists and clean-energy executives last week in Mountain View, California, that she was “thinking of punting,” saying the specifics of the emissions-trading program may not be ready for 1-2 more years.

“I think the cap-and-trade system needs to be thought through and I don’t think that has been done yet,” said Jerry Hill, a member of the Air Resources Board. “It would be a good idea to take our time to be sure what we do create is successful.”

Greentech VCs aren’t thrilled, but I think this is wise, and applaud CARB for recognizing the scale of the design task rather than launching a half-baked program. Still, delay is costly, and design complexity contributes to delay. California has a lot of balls in the air, with a hybrid design involving a dozen or so sectoral initiatives, a low-carbon fuel standard, and cap & trade. As I said a while ago,

My fear is that the analysis of GHG initiatives will ultimately prove overconstrained and underpowered, and that as a result implementation will ultimately crumble when called upon to make real changes (like California’s ambitious executive order targeting 2050 emissions 80% below 1990 levels). California’s electric power market restructuring debacle jumps to mind. I think underpowered analysis is partly a function of history. Other programs, like emissions markets for SOx, energy efficiency programs, and local regulation of criteria air pollutants have all worked OK in the past. However, these activities have all been marginal, in the sense that they affect only a small fraction of energy costs and a tinier fraction of GDP. Thus they had limited potential to create noticeable unwanted side effects that might lead to damaging economic ripple effects or the undoing of the policy. Given that, it was feasible to proceed by cautious experimentation. Greenhouse gas regulation, if it is to meet ambitious goals, will not be marginal; it will be pervasive and obvious. Analysis budgets of a few million dollars (much less in most regions) seem out of proportion with the multibillion $/year scale of the problem.

One result of the omission of a true top-down design process is that there has been no serious comparison of proposed emissions trading schemes with carbon taxes, though there are many strong substantive arguments in favor of the latter. In California, for example, the CPUC Interim Opinion on Greenhouse Gas Regulatory Strategies states, ‘We did not seriously consider the carbon tax option in the course of this proceeding, due to the fact that, if such a policy were implemented, it would most likely be imposed on the economy as a whole by ARB.’ It’s hard for CARB to consider a tax, because legislation does not authorize it. It’s hard for legislators to enable a tax, because a supermajority is required and it’s generally considered poor form to say the word ‘tax’ out loud. Thus, for better or for worse, a major option is foreclosed at the outset.

At the risk of repeating myself,

The BC tax demonstrates a huge advantage of a carbon tax over cap & trade: it can be implemented quickly. The tax was introduced in the Feb. 19 budget, and switched on July 1st. By contrast, the WCI and California cap & trade systems have been underway much longer, and still are no where near going live.

My preferred approach to GHG regulation would be, in a nutshell: (a) get a price on emissions ASAP, in as simple and stable a way as possible; if you can’t have a tax, design cap & trade to look like a tax (b) get other regions to harmonize (c) then do all that other stuff: removing institutional barriers to change, R&D, efficiency and renewable incentives, in roughly that order (c) dispense with portfolio standards and other mandates unless (a) through (c) aren’t doing the job.

My Bathtub is Nonlinear

I’m working on raising my kids as systems thinkers. I’ve been meaning to share some of our adventures here for some time, so here’s a first installment, from quite a while back.

I decided to ignore the great online resources for system dynamics education and reinvent the wheel. But where to start? I wanted an exercise that included stocks and flows, accumulation, graph reading, estimation, and data collection, with as much excitement as could be had indoors. (It was 20 below outside, so fire and explosions weren’t an option).

We grabbed a sheet of graph paper, fat pens, a yardstick, and a stopwatch and headed for the bathtub. Step 1 (to sustain interest) was turn on the tap to fill the tub. While it filled, I drew time and depth axes on the graph paper and explained what we were trying to do. That involved explaining what a graph was for, and what locations on the axes meant (they were perhaps 5 and 6 and probably hadn’t seen a graph of behavior over time before).

When the tub was full, we made a few guesses about how long it might take to empty, then started the clock and opened the drain. Every ten or twenty seconds, we’d stop the timer, take a depth reading, and plot the result on our graph. After a few tries, the kids could place the points. About half way, we took a longer pause to discuss the trajectory so far. I proposed a few forecasts of how the second half of the tub might drain – slowing, speeding up, etc. Each of us took a guess about time-to-empty. Naturally my own guess was roughly consistent with exponential decay. Then we reopened the drain and collected data until the tub was dry.

To my astonishment, the resulting plot showed a perfectly linear decline in water depth, all the way to zero (as best we could measure). In hindsight, it’s not all that strange, because the tub tapers at the bottom, so that a constant linear decline in the outflow rate corresponds with the declining volumetric flow rate you’d expect (from decreasing pressure at the outlet as the water gets shallower). Still, I find it rather amazing that the shape of the tub (and perhaps nonlinearity in the drain’s behavior) results in such a perfectly linear trajectory.

We spent a fair amount of time further exploring bathtub dynamics, with much filling and emptying. When the quantity of water on the floor got too alarming, we moved to the sink to explore equilibrium by trying to balance the tap inflow and drain outflow, which is surprisingly difficult.

We lost track of our original results, so we recently repeated the experiment. This time, we measured the filling as well as the draining, shown below on the same axes. The dotted lines are our data; others are our prior guesses. Again, there’s no sign of exponential draining – it’s a linear rush to the finish line. Filling – which you’d expect to be a perfect ramp if the tub had constant volume per depth – is initially fast, then slows slightly as the tapered bottom area is full. However, that effect doesn’t seem to be big enough to explain the outflow behavior.

Bathtub data

I’ve just realized that I have a straight-sided horse trough lying about, so I think we may need to head outside for another test …

Update: the follow-on to this is rather important.

State Emissions Commitments

For the Pangaea model, colleagues have been compiling a useful table of international emissions commitments. That will let us test whether, if fulfilled, those commitments move the needle on global atmospheric GHG concentrations and temperatures (currently they don’t).

I’ve been looking for the equivalent for US states, and found it at Pew Climate. It’s hard to get a mental picture of the emissions trajectory implied by the various commitments in the table, so I combined them with emissions data from EPA (fossil fuel CO2 only) to reconcile all the variations in base years and growth patterns.

The history of emissions from 1990 to 2005, plus future commitments, looks like this:

State emissions commitments, vs. 1990, CO2 basis

Note that some states have committed to “long term” reductions, without a specific date, which are shown above just beyond 2050. There’s a remarkable amount of variation in 1990-2005 trends, ranging from Arizona (up 55%) to Massachusetts (nearly flat).

Continue reading “State Emissions Commitments”

This is going to be big …

I stopped by the county offices here in Montana to register my car. SpongeBob Squarepants was wandering down the sidewalk. More amazingly, there was a line of early voters stretching out the door of the Clerk’s office, down the hall, and up the stairs to the second floor. The motor vehicle registrar told me that 20,000 people have registered to vote in the last few weeks. That’s 1/4 of the population. It looks like turnout is going to be huge.

I hope the system can keep up. It seems reasonable to think that many jurisdictions have become habituated to low turnout, and simply don’t have the capacity to handle everyone exercising their rights.

Vote early, vote often.

Is the BC Carbon Tax Fair?

That’s the title of a post today at The Progressive Economics Forum, introducing a new report from the Canadian Centre for Policy Alternatives.

The bottom line:

In this study, we model the distribution of BC’s carbon tax and recycling measures. Our results conirm that BC’s carbon tax, in and of itself, is regressive. However, the overall carbon tax and recycling framework is modestly progressive in 2008/09 ’” that is, low-income families get back more in credits, on average, than they pay in carbon taxes. If the low-income credit is not expanded, however, the regime will shift to become regressive by 2010/11. It is important for policy makers to rectify this situation in the 2009 and future budgets by minimally ensuring that the credit grows in line with the carbon tax.

A related problem:

A second concern with the carbon tax regime is that tax cuts undermine a progressive outcome at the top of the income scale. In 2008/09, personal and corporate income tax cuts lead to an average net gain for the top 20% of households that is larger in dollar terms than for the bottom 40%.

I plotted the results in the report’s tables to show some of these effects. In 2009, the lowest income groups (quintiles 1-3) come out a little ahead, but the 4th quintile faces a net loss, while the top income group is overcompensated by the corporate tax cut:

BC carbon tax incidence and rebate distribution

Continue reading “Is the BC Carbon Tax Fair?”