Modeled Behavior tells A Tale of Two Recessions, noting a rather shocking statistic:

as of the last few years the auto fleet in the United States has begun to shrink. That is, we are scrapping cars at a faster rate than we are producing them.

Unless something changes in the next 18 months, our scrappage rate will begin to exceed new cars sales by the millions of units per year. In a country that is still growing in population and still adding drivers every year its hard to explain why the optimal path is suddenly for the vehicle fleet to shrink.

Similarly, the Lesser Depression has resulted in reduced carbon emissions across the board, putting the US well on its way to meeting emissions reduction targets set in Copenhagen. But it also means that we may not even try to meet our commitments to invest in climate change mitigation and adaptation efforts in developing nations.

To a degree, this echoes a theme Grist's David Roberts discussed a month ago (we discussed it here). While various folks have taken stabs at devising economic systems that can be stable and happy without economic growth, that's not the system we have now. Those emissions reductions are coming because people are out of work, because factories are sitting idle, because vital infrastructure is being neglected. We're emitting less carbon dioxide because we aren't building as many cars, because the construction bubble burst and took with it demand for steel and concrete. But people still need houses, and they still need to get around. We can hardly celebrate the fact that less gas is being burned because fewer people have jobs to drive to.

We can hope, of course, that people who have decided to go without cars during this economic collapse will stick with that decision when they can once again afford a car. And we can hope that people who find ways to save on gas today will keep doing that when gas prices fall or salaries increase.

But it'd be far better if we as a nation, and as individual states and cities, could find ways to lock in those changes. Buying new buses and trains would make it easier for people to stick with their carless lifestyle when the economy turns around, and it'd put people back to work building trains and buses and laying new track, and maybe repaving streets and rebuilding bridges so that they can handle heavier bus traffic.

We're seeing some of that already. In Kansas, the Climate and Energy Project has been reaching out to communities across the state, finding ways to encourage investments in energy efficiency and clean technology. They've worked closely with utilities across the state to make it cheaper and easier for energy consumers to upgrade their homes and businesses. They created competitions between cities to see which could save the most energy.

Earlier this week, CEP board member Nancy Jackson came to Berkeley to speak with folks from Lawrence Berkeley Labs, including policy and consumer behavior scientist Merrian Fuller. In this year's competition, Jackson said, Lawrence and Manhattan are competing head-to-head, and it sounds like the competition is pretty intense. These competitions and other efforts have had a huge effect in Kansas, bringing together governments and utilities and communities to find ways to save energy, but the future of those gains remains to be seen. CEP and similar programs in other states got substantial funding from the 2009 stimulus bill, but that money will run out soon. The successes and the knowledge gained from experiments across the country could all be lost if with that funding.

If that knowledge is lost, we also lose the ability to build on those successes once the economy starts growing substantially, let alone to use that knowledge to create new jobs and to spur needed economic growth, and to direct it in environmentally safe directions.