I generally assume that nearly all Americans are environmentalists. By this, I mean, we want to preserve our environment to be a healthy place for everyone to live in.
Our wedged political state makes it hard to acknowledge this. Environmental policy is a running proxy battle over other cultural identifiers.
Those who identify culturally as environmentalist probably tend to make more personal choices geared at being more environmentally friendly: compositing, bicycling rather than driving, eating organic, using reusable bags, and the like.
The Dilemma: Transit
Environmentalism is all about the numbers. If you want to reduce a certain pollutant like CO2, what you do is really "environmental" only if it reduces those pollutants.
Knowing whether you're doing that is hard. Often we do stuff that seems to have an intuitive link to improving the environment, but the link isn't always there, or isn't there in the way we think.
I actually first thought about this post while having dinner with a dear friend who had the following shirt:
My internal quibble seems semantic at first. "Well it's not technically infinite. If you bike a lot, you need to eat more, and that means more fuel's consumed in the production and transit of that food." But it's totally trivial, right?
Looking at a report from the Pacific Institute (which advocates reducing GHG emissions), they compare the GHG emissions of walking vs. driving. There are tons of variables and assumptions you can bake in (what kind of car? what kind of diet? etc), but they found that sometimes, especially if you eat a lot of beef, you create less GHG emissions by driving than walking. If your diet has lower GHG emissions, it's better to walk, but not by as much as you'd think.
If you have an electric car its lifecycle GHG emissions are actually less than half that of a gas car (and because there's a lot of GHG emissions in making the battery and other stuff, the marginal per-mile GHG emissions are even lower in comparison), so that changes the walking-driving comparison dramatically. (To be fair, I have neither found nor made a grand matrix of diets vs. vehicles for this comparison.)
Now in the case of bikes, you're actually consuming fewer calories per mile (about half), so it's a lower-GHG choice in the long-term (again, the bicycle has lifecycle emissions from its manufacture and transit). But the "infinity" logo is actually substantially misleading: there isn't a big gap in lifetime carbon emissions from biking vs. driving an electric car--and if you're in a country with lots of zero-emission electricity production, driving the car might be the lowest-GHG choice. That said, if your sources of electricity are almost all from coal (like in parts of the midwest US or Appalachia), then the electric car looks a lot more like a gasoline car.
Man, that's complicated.
More Dilemma: Diet
I got excited about the "diet" thing and did some more research there. Beef is so GHG-intensive that you might just have a bigger GHG impact giving up beef rather than your car. It also of course has much higher land usage per calorie than chicken, pork, or vegetables.
I know a lot of environmentalists who don't eat beef or any meat (vegetables still win on GHG per calorie) for this reason.
But many of them also don't eat GMO, or prefer organic food. GMOs, though, use less land and carbon per calorie (because they have higher yield rates and require less tillage) and require less pesticides (due to genetic resistance) than conventional foods. Organic foods fare the worst: their per-acre yield is on average 25% lower (with a range by product from almost no difference to over 33% difference) than conventional production, which means more land use and more gasoline in the equipment to work the land. In the case of organics vs. conventionals, an environmentally-conscious consumer will also need to think about how they balance GHG emissions with pesticide use--I don't even know how to begin comparing those mathematically.
When buying your food, things get even wackier. If you use a cotton tote bag, you need to use it 327 times to match the carbon emissions of a typical plastic HDPE grocery store bag--and that's if you throw out the plastic bag, rather than use it as a trashcan liner (then you double the usage requirement). But the same study shows that pretty much nobody succeeds in using their tote bag that much. For most people, plastic is the way to go to limit GHG emissions.
And when wiping down, your paper napkins use less CO2 and 60x less water (with an assumption of 50 napkins thrown out per one wash of the cotton napkin) per use than cotton.
Culture and Signaling
The math behind environmentally-friendly behavior is astoundingly complex, and even the meta-analyses I've looked into aren't always highly conclusive or decisive. Comparing different environmental factors (GHG vs other things) is tough to do unless you are able to put some equivalent economic damage factor on each unit of these pollutants.
Given that, it's not surprising that most people simplify. There is a chance that many people are using shortcut heuristics:
- If it's less industrial, it's better for the environment
- If it's reusable, it's better for the environment
Based on those heuristics, there's cultural pressure for people to use less industrial stuff (walking rather than driving, organics vs. GMO), and to use more reusable stuff (tote bags rather than recyclable bags).
But such heuristics may be ultimately counter-productive. Making a real difference to the environment will require abandoning a loose effort to fit into environmental culture, and instead dive deep into the data. It requires commitment: if you convert back to plastic bags, or start eating GMOs, you may take flak from people around you. You may need to explain yourself a hundred times.
And you'll need to decide to what extent your priority is to save the planet, or to fit in.