An engineering class at MIT has released the results of a study of carbon emissions based on the full range of USA-based lifestyles, and their findings show that no matter how poor you are – no matter how little you own or how many resources you personally use – there is a floor to your carbon emissions portion – your footprint – below which you cannot sink. And that floor is twice as high as the minimum emissions footprint of people living in any other country.

This is not encouraging news for all of us who are making an honest effort to reduce our impact by changing the way we live, for it indicates that simply by living in this country and enjoying its benefits – even if they amount to using the cast-offs of others – we each carry the karma of American affluence and energy profligacy.

While it may seem surprising that even people whose lifestyles don’t appear extravagant–the homeless, monks, children–are responsible for significant greenhouse gas emissions, one major factor is the array of government services that are available to everyone in the United States. These basic services-including police, roads, libraries, the court system and the military-were allocated equally to everyone in the country in this study. Other services that are more specific, such as education or Medicare, were allocated only to those who actually make use of them.

The students conducted detailed interviews or made detailed estimates of the energy usage of 18 lifestyles, spanning the gamut from a vegetarian college student and a 5-year-old up to the ultra-rich-Oprah Winfrey and Bill Gates. The energy impact for the rich was estimated from published sources, while all the others were based on direct interviews. The average annual carbon dioxide emissions per person, they found, was 20 metric tons, compared to a world average of four tons.

But the “floor” below which nobody in the U.S. can reach, no matter what their energy choices, turned out to be 8.5 tons, the class found. That was the usage calculated for a homeless person who ate in soup kitchens and slept in homeless shelters. The person with the lowest energy usage was a Buddhist monk who spent six months of every year living in the forest and had total annual spending of $12,500. His carbon footprint was 10.5 tons.

Go spend a year or two in an underdeveloped country, then return to the U.S., with its wealth of highways, vehicles, buildings, services and store inventories – and its obscenely huge defense budget – and it’s pretty clear how the findings of the class could be so. Plus, as Timothy Gutowski, the class’s professor, explains, we are SO affluent that even when we take green steps, we’re likely to offset them with other choices available to us in this culture of unlimited choices.

“When you save energy, you save money,” Gutowski explains. “The question is, how are you going to spend that money?”

The students looked at the factors within each person’s control that might lead to a reduction in their carbon output. They found that achieving significant reductions for the most part required drastic changes that would likely be unacceptable to most people. As a result, they said, “this all suggests to us very significant limits to voluntary actions to reduce impacts, both at a personal level and at a national level.”

Maybe, then, my 12 years of living collectively and sharing resources, had some merit. That lifestyle was certainly “unacceptable to most people.” Back to the future, everyone.

Thanks to Smart Mobs and ZDnet for the link.