Save a Tonne

Someone wrote to say that it is absolutely inconceivable that Americans could make 90%+ reductions in carbon emissions in the next couple decades. Well maybe. But we could do a lot better.

The average American emits directly and is responsible for the emission of more than 5 tonnes of carbon annually. (See end for a comparison with other units.) How could we save even a tonne?

I’ll give two examples, beginning with a paragraph with the numbers followed by the bottom line.

Let;s start with oil use. 1,000 gallons of oil emits 2.4 tonnes directly, then there’s another 25% markup for discovery, drilling, refining, and delivery, so about 3 tonnes total. So if we consume 335 gallons less/year, that’s a tonne carbon less. The average licensed driver is behind the wheel 13,500 miles/year, more for the age group with young children, less for those who are older or younger. The average EPA determined mileage is 20.7 mpg, so the actual value is probably closer to 18 mpg. That’s 750 gallons. If you drive instead a car that gets at least 40 mpg, you’ve saved your tonne right there. Or if you drive half as far. (Or both??) The average American flies 2,000 miles/year, and this is probably a case where most of us are below average. About 10,500 miles leads to the release of one tonne. (Assume 13 miles/kg C, then add 25% for refining, etc, to make it about 10.5 miles/kg C.)

Bottom line: some combination of reducing automobile and taxi use by 335 gallons/year and cutting airplane mileage by 10,500 miles/year will let us proudly proclaim a one tonne drop.

Electricity is another prime area to cut back. The average American consumes almost 4,000 kWh/year, or 11 kWh/day. (In California, where electricity costs more and we have considerably less weather, use is close to 2,350 kWh/year or 6.5 kWh/day.) Each 5,000 kWh results in the release of one tonne carbon, more if your utility uses loads of coal, less if it has high hydroelectric and nuclear use. The three biggest savings could come from using the most efficient air conditioners and refrigerators, and switching to compact fluorescent light bulbs. Let’s just begin with the light bulbs. You can check out Energy Star to learn more about appliances, insulation, etc.)

A 100 W light bulb on 5 hours/day consumes 180 kWh/year. Replacing it with a 23 W compact fluorescent will save money just in terms of how long the bulb lasts, plus about 3/4 of that energy – it uses 45 kWh/year, saving 135 kWh/year. So switching 7.5 high use bulbs to compact fluorescent saves a tonne. Turning off lights in unused rooms saves even more. Switching to an Energy Star air conditioner reduces electricity use by 10%. (Closing off unused rooms and switching to compact fluorescents also reduces air conditioning costs – one small businessman figured the switch was the same as turning off three 1500 W heaters.) Energy Star says that its qualified refrigerator models use at least 15% less energy than required by current federal standards and 40% less energy than the conventional models sold in 2001. It doesn’t take much time to save real energy. Additionally, electric driers are major energy users – one friend switched to hanging up clothes, and enjoys seeing smaller and cheaper electric bills each month. If you have to change local regulations about hanging clothes, change them!

Bottom line: the average person can’t save one tonne in home electricity use, but the average household can. Look at where your electricity use can be lowered: switching to compact fluorescents from incandescent, replacing inefficient refrigerators and air conditioners, and using solar power to dry your clothes. Reducing your household electricity use by 13.7 kWh/day will save one tonne C/year.

Changing our energy sources, such as shifting to biofuels (plants or waste to fuels) or solar, wind, or nuclear power will also cut carbon emissions. (You’re not going to convince people to build any more dams, though a little more electricity can be obtained from using existing dams and from small-scale hydro projects.)

These don’t require major behavior changes. Of course, you have to replace the current car, and the current light bulbs and appliances. But you save money and reduce the emissions of carbon and other pollutants. And importantly, you too can be proud every time you open your electric bill.

You can see why people in energy policy are confused when people say that meeting Kyoto would harm our economy. For most of us, these small changes will help our personal economy.

Units: One tonne is a metric tonne = 1.1 American ton

Many people count carbon as carbon dioxide, which has 44/12 x the mass, so you can get to one tonne carbon dioxide 3.7 times as fast, and one ton 4 times as fast. On the other hand, you have 3.7 or 4 times as far to go, so you choose.

One Response to “Save a Tonne”

  1. Angi says:

    check out it has the top ten easiest ways to save a tonne of CO2..