Think about ahimsa, the principle of nonviolence. You're probably not actively dumping dioxin into rivers or otherwise behaving in a blatantly violent way toward the environment, but are there smaller ways in which you do more harm to the planet than you'd like?
How can you do less harm?
Unplug electronic devices (like your DVD player) when you're not using them. In the average home, 75 percent of the electricity used to power electronics is consumed when they're turned off but plugged in.
Replace incandescent light bulbs with compact fluorescent ones. True, the light isn't as inviting. But compact fluorescents use 60 percent less energy and reduce the emissions for which you're personally responsible.
Recycle, and buy products made from recycled materials.