THEGREENGROK    Statistically Speaking

Carbon Savings at Home — A Little Can Go a Long Way

by Bill Chameides | July 18th, 2008
posted by Erica Rowell (Editor)

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Read more comments at Huffington Post

Recently a Chicago Tribune reporter asked me how consumers could get the most bang for their “green” buck.

Specifically, which changes in household practices, she wanted to know, would reap the biggest reward for consumers in terms of reduced global warming pollution. The Green Grok team has come up with some simple, perhaps surprising tips to cut carbon emissions.

The average U.S. household is responsible for about 132,000 pounds of carbon dioxide (CO2) each year. Of that total, about 53,000 pounds are emitted directly from the electricity we use, the gasoline we pump, and so forth, while the rest is embedded in the goods and services we use.

It’s important to note that the numbers used here are for an averaged composite U.S. household and that they may differ considerably from your household. A number of web sites help you calculate your family’s carbon footprint, but bear in mind that usually these so-called carbon calculators estimate your direct emissions only and do not include the embedded emissions.

Controlling Your Carbon Footprint

In general, our carbon footprint is a factor of where and how we live, work, drive, fly, and play. We’ll see here that you do have some control over your own carbon footprint — maybe more than you think. Let’s look at how choices at home, on the road, and at the grocery store can all lower your carbon footprint and fight global warming.

Racking Up Annual Savings at Home …

There are a myriad of ways to reduce your carbon footprint around the house -– and why not do them? Often those energy savings translate into money savings as well. Here are a few tips and the annual savings they’ll net in terms of carbon emissions.

  • Turning down your water heater 20 degrees saves up to 220 lbs. of CO2 (Most water heaters are set to 140˚F and above when 120˚F is sufficient)
  • Raising your A/C temperature from 76˚F to 78˚F saves 300 lbs. of CO2
  • Washing your clothes in warm or cold water saves 600 lbs. of CO2
  • Replacing one 60-watt incandescent bulb with an equivalent 13-watt compact fluorescent light (CFL) saves 226 lbs. of CO2
  • Swapping 10 light bulbs for 10 CFLs saves 2,260 lbs. of CO2
  • Swapping 20 light bulbs for 20 CFLs saves 4,500 lbs. of CO2
  • Replacing an electric water heater with a gas one saves 1,850 lbs. of CO2
  • Replacing an electric water heater with a solar one saves 4,820 lbs. of CO2

These numbers suggest that the clear winner at home is using compact fluorescent bulbs. It is by far the easiest way households can have a big impact on their home energy use. After all replacing 20 light bulbs is a lot easier than installing a solar water heater and yet it has a similar carbon savings. So if you are going to do one thing, do this.

Ramping Up Annual Savings on the Road*…

  • Keeping the correct air pressure in your tires saves 300 lbs. of CO2
  • Driving 10 miles less per week saves 410 lbs. of CO2
  • Driving just 20 miles less per week saves 820 lbs. of CO2
  • Driving a car that gets 10 mpg more saves 3,000 lbs. of CO2

Driving has such a large carbon footprint that by cutting back on the miles we drive, households can easily lower their carbon footprints. Reducing the miles driven by 10 or 20 miles a week — one errand for most of us — can have a big impact. And even more important, when you shop for your next new car, pick one with the best fuel efficiency in the car class that you need.

Loading Up on Annual Savings Through Food Choices…

Switching from eating red meat and dairy to chicken, fish, or vegetables for just one day a week saves 600 lbs. of CO2

  • Eating a plant-based diet for just one day a week saves 930 lbs. of CO2
  • Choosing all ‘local’ foods saves 1400 lbs. of CO2
  • Replacing a diet of red meat and dairy with a ‘chicken, fish, and vegetables’ diet saves 4,300 lbs. of CO2
  • Replacing a diet of red meat and dairy with a plant-based diet saves 6,500 lbs. of CO2

Surprisingly, changing your diet to one that includes less meat and relies more on local produce is one of the most effective ways to lower your carbon footprint. Cutting back on meat has other benefits as well.

Now, cutting out meat is a hard choice, I know, because I eat meat too. But even so, a little restraint can go a long way. By dropping meat and dairy from your menu for just one day a week and buying local foods, you can trim your footprint by about 2,330 lbs. of CO2. Switching things up when it comes to meals starts at the grocery store — to eat low-carbon foods, you have to buy low-carbon foods. Take a look at this video for some tips on how to do this.

Recapping CO2 Savings: The Big Picture

If going vegetarian is just not your cup of tea, here’s another way to look at things that can make a big difference.

If your family were to change just 20 light bulbs and drive 20 fewer miles each week (in a 25 mpg car), you could lower your direct carbon emissions by 5,330 lbs. That’d be lowering your family’s direct carbon emissions footprint by 10 percent.

If you are really serious and do everything we’ve suggested above, you could reduce your total carbon footprint by almost 20 percent. That’s huge, and when done en masse, we could start to make a dent in our global warming pollution.

But even if we all really changed things up like many of us are starting to, it wouldn’t be enough to get us to the 80 percent cut in emissions by 2050 — the amount that many scientists believe is necessary to avoid the more dangerous consequences of climate change.

More fundamental changes in our economy and energy infrastructure are going to be needed. That is why, in addition to lowering our carbon footprint, many of my colleagues and I are calling for major policy changes on the national level. Staying informed about our country’s need to lead on this issue is critical to tackling the problem.

Let us know which steps you and your family are taking to lower your carbon footprint this summer. Leave us a comment or send us a video response on youtube.



Numbers are based on average U.S. household. Home and transportation figures include direct emissions only. Food savings include both direct and indirect life-cycle emissions. All greenhouse gas savings are on an annual basis. Average all-electric household spends $1,300 on home energy. Average kWh produces 1.32 lbs. of CO2. Average therm produces 12 lbs. of CO2. *Driving statistics are based on the average American who drives 13,000 miles annually in a car rated at 25 mpg. Burning 1 gallon of gas produces 20 lbs. of CO2. Average kWh costs $0.10.

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  1. Daniel Wedgewood
    Jul 18, 2008

    Sorry. What is a “composite U.S. household?” I was a confused by some of the numbers you used in your article until I got to the end and read your Assumptions Section – I didn’t initially know whether they were annual numbers or weekly (though the size of them suggested annual). Is it true that switching to 3 vegetarian meals a week is the same as having one complete vegetarian day per week? Your suggestions were really great. Having a link that served as a method for achieving the change (such as replaced the electric water heater with a solar one) would have been a little more useful. Some of your numbers don’t extend accurately (7 * 930 = 6510 not 6500). All of these are estimiates, of course, so the difference may not make any real diference in practical terms – but for those of us like me (a bit compulsive about math) it raises a few questions. Just an observation, not a criticism. My family has just started weighing the effects of our carbon footprint. A general question (again, maybe not practial): is there such a thing as reducing our carbon footprint below 0? Like planting X number of trees on our property, in addition to various reductions? My state, NH, has a government mandate to by electricty produced by homes and use that as a discount on the home’s energy bill. If those two equaled out (production = consumption) it seems that there would still be a net carbon footprint for us. Is that true?” title=”Questions and Observations

    • Erica Rowell
      Jul 20, 2008

      Dr. Bill Chameides responds – Hi Daniel, I’m glad your family is taking steps toward a more sustainable path. Here are a couple of sources that will help. The Department of Energy’s Energy Efficiency and Renewable Energy website ( has a lot of practical guidance. If you need more, The Rocky Mountain Institute has issued several home energy briefs that go into many more details ( Look for water heater comparisons here — although in the Northeast you might want to explore geothermal options instead of solar. I’m not sure about the specifics of NH’s program, but what you describe sounds like a net-metering program where the electric utility gives you a credit on your power bill for the excess power you generate up to a cap of what you use. Some states have moved beyond this with “buy all, sell all” programs. These programs don’t cap your credit at the amount of electricity you use, but mandate that the utilities buy and sell all the electricity you generate up to a larger cap. This is one way to open up the grid to more renewable energy and would lower your carbon footprint even more. Can a person or household reduce their carbon footprint to below zero? In theory yes, for example by buying lots of valid carbon offsets and offsetting on your own, for instance, by planting trees. In practice it would be very difficult. You would need to address more than your direct emissions from the fuels you use to drive your car and power your home, and include all the emissions embedded in all the goods and services you use. Practically, this would be extremely hard to do. If your pockets were deep enough, you could use a “personal cap and trade system” to accomplish this where you would buy credits to offset the emissions you were unable to eliminate from your lifestyle. If you take that route you need to be really careful that the offsets you buy are real; because the offset market in the U.S. is not regulated, caveat emptor is the rule (see Barring that, you can limit your embedded emissions by being conscious of the carbon associated with all the goods and services you use and choosing sustainable options. Some simple rules to live by include the basic tenets of recycling — reduce, reuse, recycle — along with opting for local products and services and remembering that when you do buy, to purchase energy-efficient materials, appliances, and vehicles. Even if you don’t know how much of an impact you are having, these steps will make a big difference in your carbon footprint.” title=”Additional sources and info

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