I appreciate a letter that stands up for the agricultural industry ("Column requires research," April 3). I know that personal farmers all over this country struggle to provide what they do. I'm also not going to advocate a decrease in domestic bovines as there is a large demand for them, myself included. Unfortunately, despite the response I have to disagree with what seems like an equally uneducated letter and will assume that you were joking when you said that cow's "breathe" methane.

The effect of this expelled gas on people isn't what worries scientists, but the cycle it might be creating on the planet does. A greenhouse gas like methane allows sunlight to enter the earth's atmosphere, but when its heat radiation (infrared) is reflected back into space, some of it is absorbed by methane and trapped in the atmosphere, causing the greenhouse effect and theoretically global warming. The soybean plants that are being harvested to produce, along with many other things, a milk substitute do not produce methane; they produce oxygen. To your credit, farmers are planting and producing these mainly genetically modified plants, which then require preemergent and incessant applications of herbicide to thrive. These persistent herbicides do not neutralize easily, typically draining to and contaminating groundwater that is later used for drinking. Nobody wins.

Many of the science professors on our campus support the idea that cows are in great numbers contributing to the effects of global warming. Some even advocate that human body heat and breath are also to blame. Is this to say we should decrease the human population by extermination and/or limited procreation? Of course not. But the fact that one person is working harder by believing that she is helping the planet can only be a good thing. Trust me, a few vegetarians and vegans are not going to be enough to shut down the largest industry in this country.