Getting Back to 350

Three hundred fifty parts per million is the latest estimate of the maximum amount of CO2 our atmosphere can tolerate and still maintain the sort of climate to which human civilization is adapted and accustomed. Why should we care in Acton, and what can we do? An International Day of Climate Action has been called for October 24, and you can participate here in Acton, in Concord, or both. I share here what keeps me going, in the hope that it reminds you of what keeps you going.

Environmentalism is one part science and one part love.

The scientific lessons from ecological studies are straightforward: In any system complex enough to support life, energy and materials travel in cycles without waste. More accurately, incomplete cycles that accumulate waste do happen temporarily, but they call forth one of two types of responses from an ecosystem: (1) new or transformed organisms use that waste as a source for energy or food; or (2) the accumulation of toxins removes one of the players in that system and the species re-arrange how energy and materials are cycled. More starkly: breakthrough or breakdown.

But science can take us only so far. Our love of particular places or particular ways of being in the world is what motivates us to environmental action after we understand the science. In my case, the woods of Acton are a haven that provides a constant source of emotional and spiritual renewal. I go there to remind myself that I am only a part of a much larger and more complex world. I also remember that I have a certain responsibility to sustain these magical places — to understand what threatens them, and to understand what I might do to deal with the threats. As a human in love with the woods, I prefer breakthrough to breakdown.

Back to the science. One result of these constantly adjusting cycles on our planet is the climate. Plants use more carbon dioxide (CO2) than they generate, and animals generate more CO2 than they use — a fine bargain. Levels of CO2 in the atmosphere have remained mostly stable over the eons, absent big breakdown events such as major volcanoes and giant meteor crashes, or big breakthrough events such as the emergence of animal life. Stable CO2 levels have the important side effect of keeping Earth's average temperature in a range that is helpful for both plants and animals. Carbon dioxide is one of the key components of the greenhouse effect that keeps our planet from freezing: our atmosphere lets energy in from the sun, and then lets only a portion of it reflect back out. But too much CO2 means too much energy accumulation, and a resulting rise in average temperatures. Changes in average temperatures, in turn affects the spatial and temporal ranges of plants and animals, each species in a different way. A big shift in temperature is a breakdown event — species die off and ecosystem functioning degrades. Ecosystems become simpler and more dominated by a few generalist species, such as the invasive plants that are turning parts of our forests into monocultural wastelands.

Humans are in the middle of creating one of these breakdown events. We are taking carbon-intensive materials out of the ground for energy, mostly in coal and oil, and putting most of the residual carbon into the atmosphere in the form of CO2. We are doing this extraction millions of times faster than the normal cycles that bring carbon back into the ground.

In Acton, a largely residential town, what we do with these materials from the ground can be approximated as follows: We use gasoline to power our cars, and we use electricity generated from coal to power our houses. Everything else that happens in town has a much smaller impact on CO2 levels, so transportation and residential electricity reductions will give us the biggest bang for our conserving buck.

What can we do to use less fuel for car transportation? Many Acton residents are switching to less fuel-intensive cars, or driving less. Consider supporting the efforts of the Economic Development Council to bring more jobs to Acton. Or consider telecommuting. Or support the Transportation Advisory Council's shuttle pilot program. Or help the South Acton Train Station Advisory Committee wrestle with how to expand parking options for train commuters without making the traffic situation around South Acton even worse than it is today.

What can we do to make our houses use less fossil-fuel energy? The first step is to call your energy provider, such as NSTAR, and get a free energy audit. It's now more cost effective in Massachusetts for utilities to reduce energy use than to finance new power plants, so they are offering a variety of incentives to get you to use less. There are also state and federal tax incentives and rebates to support efficiency efforts. You could sign up for NSTAR’s renewable electricity program — NSTAR Green — through which you can purchase either 50% or 100% of your electricity from an upstate New York wind farm. You might install an on-demand hot water heating system. Or you could call a local installer and get a free quote on putting up solar panels or solar hot water heaters.

Much of what we need to do goes beyond Acton. To get the power of the national and world economies moving toward “decarbonization” requires strong legal and tax and trade agreements to shift incentives. World leaders are meeting in Copenhagen in December to settle on what should replace the aging Kyoto accord. The October 24 day of action is designed to send a strong signal to those leaders that people do want effective agreements and action to move us back toward a livable climate system, where CO2 makes up 350 parts per million or less of our atmosphere. And I want to continue to be able to go into the woods and see recognizable plants and animals making up the forests that surround us and sustain us.

Join me on October 24, at 2:00 PM in Concord at the Old North Bridge, or at 12:00 in Acton (in the parking lot behind Town Hall), where we will form a bike caravan, and a hybrid-car carpool caravan, to make our way over to Concord. Join me because we love it here, because we want our rich natural heritage to be preserved, and because we are willing to stand up and say so.