You would think, listening to some environmentalists, that all that is holding us back from saving the earth is for the scales to fall from the eyes of greedy corporations and an ignorant, complacent populace. There is a simple way to tell who is environmentally naughty, and who is environmentally nice. Science knows what is best, but people aren’t listening to the science! There is a well-understood and well-accepted consensus of what is environmentally-friendly and what is not. And how apt that the naughties should get a piece of coal! But I will attempt to show here that it’s not even close to that simple.

Let’s begin with an example where even Talmudic scholars a difficult time choosing the right. Monterey Bay Aquarium publishes an annual “seafood watch” chart, which you can print out and carry with you, which you will need to do, because it is updated annually, and varies according to to region you live in. There is a separate chart for sushi. Turns out which fish are naughty to eat, and which fish are nice to eat, is not very easy to keep straight. I don’t mean this as a criticism of the good folks at Seafood Watch, only that here, at last, we have some people who have grasped the complexity of just one aspect of the many environmental problems we face, and considering our impact on the environment. You might just say, forget it, I’ll eat meat instead, but meat (especially beef, but it depends on where and how it was raised) is probably worse for the environment, and also less healthy for you. Or perhaps we should all go vegetarian altogether and not bother? Until we do so, however, fish cultivated in an environmentally-sustainable ways is one of the best sources of protein available, from a health as well as environmental impact and low energy standpoint. 70 percent of the planet is water, after all.

As long as we’re talking about eating plants, let’s consider the environmental and health effects of pesticides. Most people believe that pesticides are bad, and that therefore removing them from our food chain is good. However, cultivation methods excluding pesticides are less efficient: they take more land, and therefore more water, and they also cost more. As Steven Landsburg points out, the net effect is that poor people eat fewer vegetables, and therefore get more cancer than they would if they were eating pesticide-laden veggies. It is better to eat vegetables with pesticides than none at all, overall.

As an aside, I might mention that there may be some very good reasons to eat locally-grown meat and produce (i.e., it tastes better, you want to support your local economy for nativist reasons), but environmental reasons aren’t one of them. Locally grown food is produced less efficiently than agri-business food, taking up more land and using more resources (even when you factor in transportation costs) than high-density centralized farm operations. Also, speaking of organically grown vegetables, they use organic fertilizers rather than synthetic fertilizers, which tend to spread more disease. E coli outbreaks are much more common among organic vegetables than regular ones because organic vegetables are fertilized with chicken excrement, which carries a host of pathogens. Synthetic nitrogen, I shouldn’t have to add, doesn’t carry disease.

The two prior examples show something important, which is that supposed “environmentally-friendly” product and actions often have adverse health effects. That effect becomes even greater when you look at a cost-benefit analysis of environmental regulations. Bjorn Lomborg points out that providing clean water to the two billion people who don’t have it currently is two to three orders of magnitude cheaper than the global carbon cap and trade taxation schemes being discussed currently, and yet will save more lives than are lost in any of the IPCC’s prediction scenarios.

It does raise an important point in our quest to develop a Bentham-esque utilitarian approach to our personal environmental impact. What is our circle of concern? Our local region? Our nation? Our species? The entire planet? If the latter, then how are we to weight the claims of the various species? To take increasing carbon concentrations in our atmosphere, all the plants (at least the ones with C3 photosynthesis metabolic pathways) would definitely prefer much greater carbon concentrations than we have even now, they evolved during a time when CO2 concentrations were much higher than they are even now, and it costs them quite a bit (in water loss) to breathe carbon at these relatively low concentrations.

On the other hand, it appears that a lot of that excess CO2 goes into the oceans, where it acidifies them and seems to damage coral reefs and the vast number of species that depend on them.

If we take the other approach, and draw our circle of concern most narrowly, then it seems fairly clear that rising global temperatures would, on balance, help a farmer in Canada much more than it would harm him. Likewise, most computer models (though I personally don’t feel that any of them are worth the RAM they are stored in) predict rising temperatures will increase precipitation, so a Bedouin in the Sahara would feel likewise. Those inhabiting the coasts (which is much more of us, proportionately) would not agree.

If you feel, as many people claim they do, that increasing carbon in our atmosphere is the preeminent and most urgent environmental crisis of our time, then a number of actions should be taken that are not routinely. for instance, do you compost? This is seen as a “good” thing, but if you are worried about carbon emissions above all else, then you should not. You should double-bag your compost waste and put it in the trash where it can be buried in a landfill that won’t release the carbon dioxide from your decaying waste. You should do the same thing with grass clippings. Likewise, you should not recycle any paper products. Aside from the fact that recycling paper produces more waste and uses more energy than making paper from trees, we should be burying that paper waste where it cannot be released in the atmosphere (most landfills are like this nowadays), and growing more trees to suck yet more carbon out of the atmosphere, then chop them down, and grow more, and so on.

And speaking of trees, if we want to reduce carbon emissions above all else, then we should chop down all old growth forests, and to heck with the spotted owl. Old growth forests are carbon neutral, because the trees have stopped growing. They grow leaves every year, but they fall to the forest floor and decompose, releasing essentially all of the carbon back into the atmosphere that they’ve pulled out of it earlier in the year. New growth forests put that carbon into growth. When they stop growing, we should chop them down. (I do find it interesting that the spotted owl seems to count more than out-of-work lumberjacks in many peoples’ moral calculus. You might say it’s because the spotted owl is dead and the lumberjack is not. I would say, don’t be so sure. Have you looked at the death rates due to suicide, alcoholism, etc. among the unemployed?)

We might be inclined to give the old growth trees a pass, as I am (though in doing so we would have to admit that sometimes other considerations trump reducing carbon dioxide emissions), but everyone should be sobered at the huge contribution agricultural waste makes to greenhouse gases (not only CO2, but even more potent greenhouse cases like methane are released in significant quantities). Agricultural waste accounts for about 30% of human carbon emissions, roughly what automobile emissions contribute, even though many of these sources could be much more cheaply sequestered than the gaseous carbon emitted from our tailpipes.

Speaking of automobiles, it is not clear that the Prius, with its rather modest improvements in MPG, really does more for the environment than it costs when you factor in the environmental impact of battery production and the rest of the car, over its usable lifetime. We would probably be better off using that money to convert as many vehicles as we could to natural gas, which emits less carbon than gasoline and can be produced domestically.

I conclude by asking you to consider the humble dishwasher. Surely, we should wash our dishes by hand, saving energy and using some health-promoting elbow grease? Perhaps. That might save some energy, especially if you used cold water. But if you are concerned about saving water, then you should use the dishwasher instead. Even if the dishwasher is less than half full, your dishwasher uses less water than you do washing the same amount of dishes, just make sure you don’t rinse them beforehand.