Dialectics: Big Business and being "green"

It seems that as Americans, we love to hate all those large, industrial businesses. I used to think so too. I thought that these large companies were only concerned with two things: money and power. I thought that they were the culprits leading the global warming crisis: overproducing, exploiting, and wasting. However, my opinion was very recently challenged...
I recently read an article that talked about the new incentives big companies have to cut back on greenhouse emissions, and become more sustainable. The article reported that big companies first started getting this idea when research showed that many of their problems would be cheaper to fix, rather than try to avoid. The companies beginning this revolution - Chevron, Coca-Cola, and.....Wal-mart!
At this point I almost stopped reading the article. Walmart?!?! You mean, the ring master of the global big-business crisis?
However, as I continued I realized that I was unaware of all these big steps Wal-mart was taking to become 'greener'. A separate article in BusinessWeek stated that Wal-mart has slashed its electricity bill by 17% since 2002, have saved 2.4 million in shipping costs by using less packaging, and currently ranks 5th in one of Brazil’s “greenest companies” list.
After reading the article, it seemed to pose the idea that these large companies are indeed the key to leading a green revolution. They certainly have the social aspect with them. However, I wasn’t completely convinced….
While although places like Wal-mart are becoming greener, they still are much more wasteful than smaller, locally run business they have replaced in urban towns and suburbs. We recently discussed a DBQ in social studies where a local supplier commented on the construction of a local Wal-Mart, and how it completely destroyed his business.
I’m trying to avoid completely jumping onto the Wal-mart bandwagon, but even after writing this post, I remain skeptical.
These large companies certainly have the power and money to start a global green revolution, it just depends on if they actually will. It seems that these green innovations are just for the publicity and attention, rather than their actual concern with the environment.
It seems unfortunate, but at this late in the game, it seems as though these big companies, that already harvest much of our attention and money, are among the only ones to be able to begin a green uprising.