I remember when stores first started saying, "Paper or plastic?"- I had the following conversation more than once:
"I guess you don't care about the Earth."
"Actually, if not reused and recycled properly, paper bags are worse for the planet than plastic."
"That's not true! What do you know about it, anyway?"
"I work in the industry."
"Well, the Vice President says using paper bags is one of the things we can do to save the planet. Who knows more about it, you or Al Gore?"
According to the Daily Mail, I did know more about it than Al Gore- paper bags need to be reused three times to fall below the environmental impact level of plastic bags- and that's assuming you didn't reuse the plastic bag. And that's simply not possible, because the paper handles come off of an third of them between the store and the car- I've learned to stoop and waddle when using paper bags, so that when they rip or the straps fail they'll only have a inch to fall, and hopefully the groceries won't break open.
Then came the cloth bags, with things like "I heart the Earth" on them- now there's a reusable bag that's definitely an improvement over the plastic! Or maybe not... "As a greater amount of energy goes into making a cloth carrier than a polythene one, a cotton bag has to be used 131 times before it has the same environmental impact than its plastic counterpart. And if a plastic bag is re-used as a bin liner, a cotton bag has to be used 173 times - nearly every day of the year - before its ecological impact is as low as a plastic bag on a host of factors including greenhouse gas emissions over its lifetime." I don't know how they got "nearly every day of the year", but if you normally shop once a week, you'd have to use the same cloth bag for three and a half years just to break even with the plastic bag. And that doesn't count the environmental impact of the vivid plastisol designs silkscreened on them- you don't want to know the impact of those chemicals!
Then there's those damn Compact Flourescent bulbs. I've written about them before, here and here, but here's a simpler way to think about it: you've heard the environmentalists' slogan, "Think globally, buy locally"? Well, no CFLs are made locally- all CFLs are imported, all of them.
I know what I'm about to say can be applied to a whole lot of things, but... why can't we think things through before committing so much to them?