At the Zen Center, we precede each meal with a chant that begins with the verse, "Innumerable labors have brought us this food. We should know how it comes to us."

In the American service economy, the labors that have provided our food, our clothes, our heat, our electricity and so on are truly innumerable. We may be conscious of our recycling efforts at home, but what do we know of the efforts of the trucking company that carried our tomatoes from the farm to the supermarket? And what about the supermarket? We may be mindful of conserving gasoline by reducing the number of unnecessary trips, but what about the fuel consumption of the jet carrying troops to Iraq to fight a war to protect our access to oil?

Paul Hawken, one of the two founders of Smith & Hawken, is also a renowned author of environmental books - The Ecology of Commerce served as the wake-up call to Ray Anderson of Interface, Inc., and Bill Clinton called Natural Capitalism: Creating the Next Industrial Revolution one of the five most important books in the world today. Addressing the American consumer culture, Hawken noted that the average American family of four consumes four million pounds of material every year to support their lifestyle, or 11,000 lbs a day, 7.5 pounds per minute. Much of this consumption is out of sight and out of mind - it is offshore, in mines, stockyards, slag heaps, landfills, and wastewater treatment plants.

It's easy to fall into the trap of managing only a household's disposal end of the waste stream, and ignoring the upstream consequences of our consumption. But this ignores the fact that we are all part of a global web of supply and demand, and that our demand for fresh fruit in the dead of winter may create an oil slick in the waters of a Central American shipping port.

How can we take responsibility for a larger share of the impact? How can we personally move toward a more sustainable lifestyle?

Grist Magazine recently came up with an excellent idea for at least a part of the problem - instead of waiting for the United States to come around, if ever, to adopting the Kyoto treaty, adjust your lifestyle now and personally lower your greenhouse-gas emissions to 5 percent below 1990 levels, like the treaty calls for industrial nations to do. If enough people do it, it will make some difference in the national rate, and may change the national consciousnesss enough that the U.S. might actually ratify the treaty some day.

I decided to go ahead and take the plunge, and have committed to trying to achieve this goal.

The first step is to calculate your current GHG emission rate. This can be done using U.S. EPA's Personal Greenhouse Gas Calculator. It's pretty simple - you need only plug in your miles drove and average utility bills, and it even suggests nationwide "averages" in case you don't know those. Unfortunately, I don't have any records of my 1990 utility bills, and a guess at the weekly miles that I drove in 1990 would be, at best, haphazard. So, I am changing my personal resolution to a commitment to reduce my GHG emissions by 10% on their 2005 levels.

It turns out that this household emits 41,696 pounds of carbon dioxide per year, based on a four-month average ending December 31. That's already well below the 60,000 lbs/year U.S. average for a household of two, but I live alone and am still vowing a 10% reduction, or a goal of 37,526 lbs/year.

My biggest contribution to CO2 released is my natural gas consumption. However, with the coldest part of winter still ahead of me, that consumption is likely to increase before it goes down. But I can still program the thermostat to a lower daytime level for when I am out at work, and I can close off some areas of the house that don't require heating at all times (like the sitting room).

Realistically, how much difference will I really make in global CO2 levels as I freeze my ass off this winter? Alone, maybe not much, but if I blog about it and encourage others to follow suit, and they do the same, we might, collectively, make some difference.