I don't buy organic. Or, at least, I don't shop for organic. I also go out of my way to avoid certain organic brands (such as Horizons milk)
However, I would posit that we went overboard with our use of fertilizers, pesticides, and herbicides and introducing organic farming techniques will bring lessons learned back to the non-organic side as well. If we choose to listen, that is.
For example, learning about improving soil and planting to attract beneficials leads to needing less fertilizer and less pesticide for farmers in west Africa. FAO Media Centre: Fewer pesticides and higher yields and incomes
There was also a sort of kind of interesting paper written on the banana industry (The Environmental Impact of the Banana Industry
). Anyone wanting to make an anti-pesticide case would be most interested in section 2.1 and 2.2. The interesting part, to me, was the comparison between plantations in Costa Rica and Ghana. I also read a few years ago (but, unfortunately am having trouble finding the source) that some organic growing techniques and lessons transferred to the pesticide-heavy growers and allowed them to reduce the amount of pesticides and herbicides they use.
I'm also concerned about the impact of fertilizer runoff on our oceans, such as the dead zone in the gulf of mexico. And I'm worried about the loss of topsoil. However, a small but increasing number of corn / soya farmers are moving to no-till methods (which I've read about in organic and alt farming sources long before it hit the mainstream). They're also injecting fertilizer below the soil surface. No-till helps with soil erosion and injecting fertilizer below the soil greatly reduces runoff and reduces the amount of fertilizer needed.
The biggest things I shop for are local and in-season. For a variety of reasons (that aren't germane to the thread at hand), I also avoid feedlot cattle and pigs and poultry that was raised in a Tyson-approved facility. But, that's me voting with my wallet to help out with what I choose to support.
In my garden, I'm growing everything organic. However, this isn't some grand statement about health or anything. Rather, I'm attempting to grow with zero outside inputs. That means no organic fertilizers other than what I can compost and make use of in my yard. It also means devoting part of my yard to green manure crops, parts to attracting predatory insects, and parts to planting beneficials (eg, marigolds in with everything, dill in certain areas, etc).
However, I will only have around 2000 sq feet under cultivation (almost enough to feed 2 people) so my needs are much different than a farmer's. This means it doesn't take me much time to squash slugs and grubs by hand if I choose. this means, once I have my apple trees in and producing, I have the luxury of simply putting nylon netting over the apples I want to keep the maggots off and using the rest for cider.