On recent evenings while walking the hood, I see wood smoke emanating from houses snuggling down for the night. Leaves are beginning to fall, and migrating birds are on the move. That can only mean one thing - it will soon be time to turn on the heat in our home.Forty to fifty percent of global energy demand is used for heating and cooling, and they contribute about the same percentage of greenhouse gases. The WorldWatch Institute reports that worldwide in 2005, half the energy use in buildings went toward space heating. The amount of energy we use to heat our homes is huge. But keeping comfortable has its environmental costs.In my part of the world using electricity for heat is common, as is using wood. Our electricity is largely hydro-powered, but dam and reservoir complexes have their own impacts. Most North Americans rely on coal, gas, or nuclear power plants to maintain indoor comfort. Unless you are generating renewable heat energy, your home heating is adding to the atmosphere's carbon load.In a recently published study by the C.D. Howe Institute, reviewed by Victoria Hollick , comparing Canadian alternative energy programs and sources, the study concludes that "the lowest-cost and highest-value programs are the renewable heat and power technologies, which include solar air heating, solar water heating , solar electricity, wind and biomass." Using solar energy for space and water heating is one of the most efficient and effective ways to reduce our carbon footprint.Until such a time that our infrastructure changes to accommodate renewable solutions, most of us will be using conventional methods for space heating. One way to reduce the impact of these old technologies is to limit our use of them. My household has started to track "Turn On The Heat Day" as a way to see when our carbon footprint is about to increase. It makes us aware of our personal contributions to a changing biosphere.When we were in the north Indian town of Mussoorie, nestled in the foothills of the Himalaya, there was no Turn On The Heat Day at the guest house we were staying at. Days were warm, but evenings could see snow and our room was quite cool. Don't take your coat off.We quickly got the hang of it, though. Stay in the sun until it sets, then don the warm clothing. Keep it on till bedtime, then jump into bed with a couple of large water bottles filled with hot water. It was a minimalist approach to our heating needs and worked rather well. It made us think about our energy use back home in Alberta, also in the foothills of a major mountain range.Since then we have made Turn On The Heat Day a fun challenge that marks the turning of the seasons (as does Turn Off The Heat Day). When the day comes depends on many variables, location, weather conditions, and personal preferences. I imagine my sister, up on a mountain side in the Kootenays has already had her Turn On The Heat Day. Out here on the coast it might be a few more weeks. We will wait and see. But as we found out during a winter storm and extended power outage, there are things that we can do to keep warm without cranking the thermostat.In December of 2006 the coast of B.C. was hammered by the worst wind storm since the 1960's. It knocked down thousands of trees and power poles, and we were without power for 4 days. Our unit's temperature sank to single digits, and bed was pretty much the place to be at any time. Out of bed, full outdoor clothing kept us warm, as did our down sleeping bags. We spent time in our bedroom (a smaller space) with a candle burning, and with our body heat, were quite comfortable.I am not advocating winter house camping for the masses, but point out that small changes adopted collectively make a huge impact. See how long you can delay Turn on the Heat Day. Get out the sweaters and wool blankets. Trust me, it's fun. Once you have had your day, and your heat source is up and running for the season, see if you can get by using it less. If a space heater will suffice, use it. Turn the thermostat down a couple degrees. Throw less wood into the fire. Exercise indoor more often. A warm body is a tremendous furnace.If possible, work toward the installation of a solar powered unit for your home. This winter I will have a small solar-powered system for our unit on the west coast. It will be useful during storm season, but we intend on using it as often as overcast winter days allow. It could power our computer and lights, as well as a small space heater.When was your Turn On The Heat Day? Have you had it yet? I would like to hear from you regarding whenday was, and what you might be doing to delay it, shy of indoor camping. Have fun, and stay warm.