In many ways organic farming is similar to other farming with regard to the environment, however the lack of pesticide use makes organic farming better for the environment overall because it does not produce the level of pollution that other farming does. Pesticides are and have been a serious environmental problem because they don't stay on the farm, they run off into the ground water which is globally interconnected.
Organic foods, grown without pesticides, keep pesticides from affecting the environment, by not allowing them to seep into the ground and infect water supplies, or making their way into other animals, causing a spread in toxicity. Organic foods are grown sustainable, rather than using fertilizers made from petroleum, which also hurts the environment. Ogranic food is good for the environment.
Seriously, get some facts people! Also, organic food needs 20% more land to grow the same amount of produce, and is more likely to be contaminated by e coli and salmonella. Not to mention that organic pesticides tend to be more harmful than conventional ones (natural does not equal healthy--arsenic is natural, after all). Some studies even indicate that organic food production produces more greenhouse gas emissions that conventionally grown food.