A substantial fraction of the world's natural gas is burned to produce nitrogen fertilizer. This is largely obtained through fracking. Fertilizers, as they are used on the large scale, are pretty bad for the environment.
You seem to be arguing that the current production of fertilizers is bad - but that doesn't implicate fertilizers in general(unless it is impossible to do otherwise for some reason).
Fertilizers in general aren't necessarily bad. It is important for us to actively recycle our phosphorous and potassium, because there is no short term replenishment of these vital elements in the soil. For more information, I highly recommend "The Humanure Handbook": http://humanurehandbook.com/downloads/Humanure_Handbook_all....
Fertilizers do increase the growth rate of plants. However, there is mounting evidence that nutritional content is inversely proportional with growth rate.