inconvenient realities

From the San Francisco Chronicle:

1. Building a new "green" house has a bigger (negative) impact than making an existing house more energy-efficient.
2. CFL lightbulbs use less energy than incandescents, but as a product they pollute more (they contain mercury). LEDs are better, but too expensive and difficult to find.
3. In some places you can get a rebate for installing energy-efficient appliances, but this encourages us to send old appliances to landfills.
4. The carbon impact of manufacturing new triple-glazed windows can be bigger than the benefit in heat savings.

This does not mean we shouldn't make low-carbon choices. It does mean that every decision involves a tradeoff. This applies not only to individual householders, but also to city planning processes. One reason why planning needs to be integrated across government departments (and various other stakeholders) is that sometimes, the best plan overall will require some aspects of the plan to be suboptimal.

For example, city planners may decide that they want to encourage high densities in residential areas in order to achieve economies of scale in the provision of bulk services (water, sewers, and so on) and to increase public transport ridership. But in some areas the targets may not be achievable because developers are not prepared to build to the target densities, or for some other reason. Then planners may need to work with lower densities, and focus instead on arranging the orientation of streets and buildings so that buildings can incorporate passive solar design and rooftop photovoltaic panels for micro generation of electricity - something that is harder to achieve in high-density areas.

This strategy would require, as a minimum, interaction between the spatial planners, urban designers, traffic engineers, land developers and the local power utility. If these players are working in isolation, as they so often are, then the strategy won't work. In planning a low-carbon world, as with so many other things, there is no universal strategy. There are, perhaps, general principles that can be used to guide decisions, but reaching appropriate decisions requires a coordinated approach.

Comments

[Atul]

Like the blog, as it has good info. Have you run across stats for environmental impact from manufacturing of a new car, (especially a hybrid), relative to keeping an older vehicle running well?

Take it easy,
Atul
www.thingsivenoticed.com

[Rory]

Here's an interesting debate on whether the lifecycle impacts of a new hybrid car negate the savings in operating cost. As with the examples in my original post, the answer is not always clear. It would be interesting to see a more thorough analysis.

My gut tells me to keep the old clunker running until I decide to scrap it for other reasons, like reliability or maintenance costs, and this is one of the reasons why adapting to peak oil will take a long time. It would take years to replace the world's fleet of conventional cars even if zero-carbon vehicles were on the market at competitive prices right now.

P.S. I had a Saturn, once.