So I'm a day late on the "Earth Day" post, but then again, every single day should be Earth Day. That said...
I want to comment, first, on what a wonderfully green thing vegetable gardening is. After you've picked up or ordered your seeds and compost, your vegetables' carbon footprint is nearly complete. It's far more fuel efficient to transport seeds and a bag of compost than months worth of veggies that are shipped from out of town, if not out of country. Try to purchase as much of the rest of your food locally grown/raised (from your farmer's market or food coop) as possible and the earth will love you, indeed! If we all did this, both we and our the local farmers would breath a little easier.
I'd also like to say that I've never understood people who disbelieve our effect on climate change. Not because I think "they're wrong and we're right," but because there are so many ways we effect our environment other than climate change. All that gasoline burning results in unhealthy smog, chemicals disposed of improperly end up in drinking water, junk takes up space in land fills that must be topped off, plastic ends up in the oceans where sea animals choke on it, and on and on and on.
Whatever side of the climate change debate you're on and no matter who is "right," there's no escaping your responsibility to this planet and future generations.