Even though I agree that we should be trying to minimize our negative impact upon the environment, I frequently have doubts about environmental claims. The biggest problem is that people tend to equate environmental impact with the stuff that they can see (e.g. deforestation). Yet even when they calculate for the invisible stuff (e.g. carbon footprint), the calculations often aren't rigorous. For example: why should the carbon footprint be a valid proxy in the case of ebooks vs. pbooks? We know that pbooks are disproportionately skewed towards carbon due to transportation (of raw materials and finished goods). Is that also the case for ebooks? ereaders, for example, are highly dependent upon the refinement of materials. That involves other chemical processes that can be incredibly damaging.

But let's take that 20 pbooks per 1 ereader argument anyhow. Then you have to consider things like how many books do people read? If a typical ereader lasts 2 years (probably longer for eInk devices and shorter for tablets, just because of the upgrade mentality) then you need to read at least 10 books per year to reach the environmental break even point.

Overall, I do agree with the taxation to offset environmental impact philosophy, but it needs to be done at the manufacturing level. If a semiconductor components manufacturer or a pulp mill goes in, their environmental impact should be assessed and they should be taxed based upon the expected cost of environmental clean-ups. This will force consumers to make better decisions because the costs will be passed on to them, and it will entice manufacturers to clean up their act.