Kendall, I'm afraid it does. The Mid-West dust bowl effect didn't happen naturally, it was caused by ppl farming the land unsustainably. It's even worse in rain-forest areas where land is being clear-cut for farming - in these areas, the Indians cut down a small area at a time, farmed it for a year and then moved on, allowing the trees to deposit leaf-mould on the site to maintain the topsoil. When it's clear-cut, it's nice and fertile for a year or two, but then the top-soil vanishes under the pressure of the rains, and the land becomes infertile. Then they have to cut down more rain-forest to get another fertile bit... And so on. FYI, the Sahara desert was originally fertile land until the trees were cut down for farming.
Even if the area's fertility is maintained (by application of natural/artificial fertiliser), there's other effects. Planting more crops than normal tends to interfere with the life cycle of the animals living in there, particularly birds which have to nest and feed young and have evolved to do this at times when the crop was historically in season. Ground-nesting birds suffer even more at harvesting time.
Off-topic, I know, but this is the general thing of the environment being regarded as something to exploit, and every industry does it - that's pretty much the definition of "industry", given that they have to produce something from raw materials, and the only raw materials are what we can find. Trouble is, I don't know of any way around this. Government subsidies are one way, but then taxes go up and that gets complaints. Besides, how do you judge how "good" someone's being? the whole system would be hopelessly open to abuse.
As far as the boycott's concerned, it seems pretty daft. It seems like the "protesters" aren't complaining about the way the oil companies are treating the environment, they're complaining that they have to pay too much to pollute the environment themselves! Excuse me if I don't sign up to this concept...
Sorcha, there's plenty of oil in Siberia. The reason we know is that a pipeline ruptured recently (year before last?) and flooded a vast area of Siberia with crude oil. It made the BBC news, at least. There was little or no clean-up, partly cos it was so difficult to get there and partly cos ecological concerns are fairly low on the list when your country's in the state Russia is. I doubt the US would get away without the clean-up operation if everything went wrong in Alaska (and with better investment it's less likely that it'd happen in the first place), but equally I doubt that they'd be able to do much once the damage has been done. All they can do really is stop the oil from spreading to other places - the area where it's been is either dead from the oil or dead from the powerful detergents used to break up the oil.