Freight Train vs. Tornado. I’ve got my money on the tornado.

Congress apparently doesn’t want to mess with the way we’re messing with Mother Nature until September.

Political capital is obviously a finite resource for the politicians on the Hill – but let’s consider the potential complimentary policies:

• The economy continues to drag, numerous economists are calling for more stimulus;
• Even without that stimulus,  we’ve got a mountain of unfunded transportation needs – to say nothing of expansions and improvements;
• The highway trust fund will run out of funds soon, while Congress is just looking to ‘patch’ it and hold off real reform for another 18 months;

and it seems like we’ve got a number of complimentary ideas to pursue.  For what it’s worth, Jim Oberstar isn’t throwing in the towel just yet on the House side, but it remains to be seen if all the moving parts (House, Senate, Administration) can get on the same page.  Given the recent focus on healthcare, it doesn’t seem all that likely.

Trees! Steve Offut has a post up at GGW about improving DC’s tree canopy cover.  Steve proposes to establish a kind of cap and trade system to encourage a better tree canopy in the city:

A portfolio standard is the other side of the same coin as cap and trade, except instead of trying to reduce or limit something, we are trying to increase it. A minimum requirement is set and each entity has to meet or exceed that requirement, either directly or by purchasing enough “credits.” A common use of this concept is a Renewable Portfolio Standard, in which a state or other entity requires that a certain percentage of electricity generated will come from renewable sources.

What makes this concept attractive is that it creates an economic incentive to go above and beyond, because when one does, the extra environmental benefits can be sold to someone else in the market.

This is an interesting concept, but I’ve got some serious reservations about the specifics of such a policy, especially if tied to regulation.  Such a proposal seems ripe for some major unintended consequences, especially coming the day after Daniel Narin’s post warning of narrowly tailored regulations having far reaching unintended consequences.

The simplest way to apply the portfolio standard to the DC urban tree canopy is to require each property to meet the same minimum requirement and ratchet it up slowly over time. Let’s assume that the current canopy is still 21% as it was in 1997. The portfolio requirement could be set at 20% to start. (It’s a good idea to make the initial standard relatively easy to accomplish in order to get the system operating and keep prices low so there is less likelihood of backlash). If my property is 6000 square feet, then I would be required to have 1200 square feet of tree canopy — either actual canopy or “credits” from someone else. Suppose my lot is 50% covered with trees — 3000 square feet. This is good, because I have an extra 1800 square feet of canopy that I can sell.

There are a number of practical concerns.  How do you account for time?  You can’t plant trees that have a ‘full’ canopy right away – that takes time to grow.  What about trees that are planted on one property, but their canopy spreads over another?  What happens if you’ve met the standard thanks to a big old tree that suddenly is destroyed thanks to disease, a storm, or some other unforeseen circumstance?

Philosophically, Ryan Avent points out the bias such a uniform standard would have in favor of lower density development.  This is the exact kind of unintended consequence we want to avoid.  Urban trees are a tremendous asset, but there’s got to be a better way to encourage them – while still recognizing that a more holistic understanding of urban areas requires balancing of various interests – and considering the complex tradeoffs where a dense urban environment doesn’t need the same kind of tree canopy coverage as a residential area to be ‘green.’

Instead, why not offer incentives for private property owners to plant trees – have DC continue to plant trees in public areas, etc.