Growing locally and in tune with the local seasons and climate (by not growing hothouse tomatoes in December, for instance) can reduce greenhouse gases. You really can make the world a better place by gardening!
First, growing your own food vastly reduces the amount of greenhouse gases produced for large-scale agriculture, food storage and distribution, and packaging. Buying locally from nearby farmers, or sharing with friends also reduces your carbon footprint, or the amount of carbon gases released into the atmosphere from activities that support your daily life.
Second, organic gardening can help reduce and even reverse the negative affects of greenhouse gases accumulating in the atmosphere by collecting and retaining carbon in organic soil. The Rodale Institute determined after a twenty-three year-long study that organic soils help retain carbon, reducing and even reversing the overabundance of greenhouse gases in the atmosphere. [Sullivan, Dan. “Organic Gardens Help Fight Global Warming.” Organic Gardening. Jan/Feb 2004, 51(1)]
The UN estimated that in order to stabilize the climate at the current levels of warming (the planet has already heated a degree or more in the last decade from greenhouse gases), we would need to immediately reduce our fossil fuel use by sixty percent. [McKibben, Bill. Maybe One: A Case for Smaller Families. New York: Plume Books, 1999.]
If every neighborhood had a community garden, and we grew at least some of our food in our own backyards using organic principles, we could go a long way towards this goal. Yes - industry needs to change. Yes - we need to drive less and ride our bikes more. But we can begin to do that literally in our own back yards by planting the seeds ourselves.
For more on how gardening can change the world, check out my book Sacred Land. (Thanks!)