Very interesting environment blog post. Here it is part of the post with the link to the original.
"It’s not the bag. It’s what’s in the bag.
by Adam Stein
...The vertical axis is “embedded energy,” meaning the amount of energy required to produce and transport the associated goods. Embedded energy equates roughly to climate change impact.
As you can plainly see, the stuff in the bag matters a lot more than the bag itself. In fact, it matters about 186 times as much. The analysis compared “four servings of two different diets: the first, a meat-based diet that included beef, potatoes, tropical fruit, and drinks such as soda; the second a vegetable-based diet composed of produce grown within the country where is was consumed and a soy-based protein source.”
The moral, obviously, is not that we should waste bags. But if you’re looking to lower your environmental impact, paper vs. plastic is maybe not the only question to be pondering."