One of the reasons frequently cited for promoting denser development is the need to reduce greenhouse gas (GHG) emissions. In places like California and Massachusetts, projects may be required to assess their impact on GHG emissions. For example, California SB 375 requires regional planning agencies like the Southern California Association of Governments (SCAG) and the Association of Bay Area Governments (ABAG) to come up with 30-year plans, and they are required to show that those plans reduce GHG emissions. Coincidentally, not long after I started drafting this piece, Juan Matute published an article on SB 375, which I would encourage you to read.
On this sudden importance of this issue, I actually think none other than Randall O’Toole is spot on. Planners long ago decided that we should be building denser development, and GHG is just another thing to add to the list of justifications. If it were demonstrated that dense development increased GHG emissions, I would not be surprised if GHG quietly disappeared from the discussion, or if it was decided that the other benefits of density outweigh GHG impacts. (The difference between me and O’Toole, which will be seen as I develop this blog, is that O’Toole thinks we should lock in suboptimal low-density market outcomes for all eternity through deed covenants, while I think density will happen on its own without planners, if we allow it.)
Intuitively, it would seem to me that higher density development should have less GHG impact. O’Toole and company say this is not so. Objectively, I don’t know who’s right, and it seems to me that both sides have a vested interest in a predetermined outcome – that is, they are not interested in finding out what type of development has the lowest GHG impact, they are interested in proving that their preferred type of development has lower GHG impact. The one thing we can say for sure is that any type of development in a pleasant climate like Los Angeles will use less energy than any type of development in the increasingly hellish climates of places like Washington DC and New York, simply because of heating and cooling demands.
Fortunately for my point of view regarding development, the truth is that nobody can predict the GHG impact of development, and it doesn’t matter. There are two reasons why: the peculiar nature of carbon dioxide as a pollutant, and the portability of pollution.
By peculiar nature of GHG emissions, I mean that they are not an unintended consequence of energy production but the very essence of energy production using fossil fuels. Nobody wants the SO2 from burning dirty coal. But you can’t get the energy out of coal without creating CO2. So, if California reduces its energy use from GHG-emitting sources, it makes those sources cheaper in other places, including the developing world, and the incentive for those places to use those sources of energy increases. Reducing SO2 emissions doesn’t create an incentive for someone else to emit SO2. CO2 is different.
By portability of pollution, I mean the ability to move the source to a less restrictive jurisdiction. For example, sewage is basically non-portable. You can’t move your entire city to a less restrictive jurisdiction and it would be pretty hard to ship your sewage to somewhere else. You treat it, and it the result is a net positive for local water resources and the planet. Power generation has some portability. You can’t move your coal power plant from Los Angeles to China but you can move it to the Navajo Reservation and ship the power back to LA. You can also increase use of less polluting fuels, like natural gas, in the restrictive jurisdiction, and ship the more polluting fuels, like coal, to places like China – something the US energy industry is doing right now. In this case there is definitely a net positive for your city – LA’s air is much cleaner since we don’t have any coal-fired plants – but there may be a negative impact for another region, and the impact on the planet is unclear. GHG is the ultimate portable pollution. If planet-wide GHG emissions do not go down, there is no net positive for anybody – not locally, not regionally, not anywhere. It doesn’t matter for California’s climate if GHG is emitted in Los Angeles or Page or Linfen.
There are some important takeaways here:
- If California reduces its consumption of GHG-producing energy, that will drive the cost of that energy down, which will increase its use in other places.
- Restrictions on development in California help encourage more development in places that emit more GHG like Texas. That is, somewhat counterintuitively, local restrictions on GHG-emitting development may increase global emissions. Matute makes the same argument on an intra-California basis, using Berkeley and Barstow.
- Since there is no local benefit to California of reducing GHG, the merit of trying to do so is questionable in the absence of national and global solutions.
None of this to say that climate change is not real or that we don’t need to address it. It is the most serious environmental problem we have ever faced. The analysis is remarkably simple: either we will find renewable sources of energy that are cost-competitive with fossil fuels, or we will not and we will suffer the consequences. In the absence of cost-competitive renewables, marginal changes to GHG emissions are irrelevant, especially given that we are already past 400ppm CO2. If we do not get cheap renewable energy, all of the world’s fossil fuels will eventually be burned, and on a timescale short enough that its actual length is irrelevant.
What this does mean is that, as Noah Smith says, we should focus our efforts on bringing down the cost of renewable energy like solar and wind. If California’s AB 32 results in more efficient industry and cheaper renewable energy, the state will have done the world a huge favor. It wouldn’t be the first time that’s happened (catalytic converters have improved countless lives), and the state’s renewable energy capacity is growing quickly. We’ve got no shortage of sun and wind here in SoCal; all we’ve got to do is put them to use. On the other hand, if AB 32 just results in industries moving to other places, it will hurt California’s economy and accomplish nothing. The outcome remains to be seen. Hey, give us credit for trying.
When it comes to development, it means we should promote development that’s efficient. Coincidentally, that’s going to be one of my main points on this blog. I was going to elaborate on how we get efficient development, but that proved to be a topic worthy of its own post.