Saturday, April 04, 2009

Ecologists cutting trees?

TILT: The reason for the seasons!

This story, about environmentalists seeking a permit to cut down trees, includes quite a few lessons in environmental geography.

Thanks to my friend Tom for pointing out the most obvious of these: this story results from the inability of an architect and two ecologists to account properly for winter sun angle. At 42 degrees north, the noon sun on the winter solstice does not go higher than 24.5 degrees above the horizon. (90-(42N+23.5S) = 24.5) Even in the summer, the sun does rise higher than 71.5 degrees, (90-(42N-23.5S) = 71.5) though it may seem to be directly overhead. Nobody should be involved in solar power without being able to map out this sort of thing.

Even without trees in the way, the solar panels are not going to be very productve in the winter, given that the winter sun provides far less energy than summer sun (otherwise, winter would be just as warm as summer). First of all, the energy is diffuse -- hold a flashlight perpendicular to a wall and then at a low angle to see this effect. The panels would need to be close to vertical to compensate fully for this factor. Secondly, although the earth is slightly closer to the sun in our winter months, the sunlight must pass through a thicker slice of the atmosphere, so less energy reaches the ground.

The story is a reminder that the "best" environmental choice may not always be obvious. An obscure folk duo known as the Pheromones once sang this about a common question at the grocery store:

Paper bag or plastic?
Going to make me spastic!
Either way we lose the trees,
Or the ozone by degrees!

They were not quite right about the ozone, but the point is well taken -- environmental purity, or simply figuring out how to do the most good or the least damage is difficult at times.

In this case, as with the grocery dilemma, more than two choices (to cut or not to cut) are available. The grocery customer can, of course, bring a canvas bag or simply carry small purchases by hand. Similarly, itwould be useful to look at the necessity of having such a large house, the total carbon impact of energy use plus landscaping, and the possibilities of using other sources of renewable energy in the low-sun season, such as electricity purchased from more productive sources elsewhere.

Finally, the story also points out an interesting conundrum about environmental decisions and spatial scale. To her credit, the homeowner in this case recused herself, as she would otherwise be ruling on her own application. This simply highlights the fact, however, that in Massachusetts the first line of enforcement of many provisions of the Federal Clean Water Act is a locally-appointed board -- very locally! I have actually completed the certification program for Conservation Commissioners in Massachusetts, and I still do not understand this: friends and neighbors get to decide if proposed actions (or completed actions) are in compliance with the Federal law. Of course some safeguards are in place and most of the people who do this work are trying to be honest, but it does politicize decisions that would be better left to professionals who are independent of the stakeholders.

1 comment:

  1. When I showed this post to my wife (and fellow blogger) Pam, she reminded me of our experience yesterday at the Borders book store in Kingston, Mass. At every register is a sign asking patrons to consider the environment before requesting a bag. Yet every clerk was pushing the bags like dope. We had to ask three times NOT to have a plastic bag for our purchase.

    So this environmental education thing has a long way to go!


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