Total U.S. Carbon Emissions for 2006

The U.S. emitted 5.887 billion metric tons of CO2 in 2006.

Here are some Department of Energy Numbers on U.S. Emissions and their change over the last 16 years.

MMT= Million Metric Tons.

U.S. carbon dioxide emissions fell 1.3 percent in 2006, from 5,955 million metric tons of carbon dioxide (MMTCO2) in 2005 to 5,877 MMTCO2 in 2006.

Changes Between 1990-2006
In the residential sector, emissions increased from 954 mmt to 1197 mmt.
In the transport sector, emissions increased from 1567 mmt to 1965 mmt.
In the industrial sector, emissions decreased from 1684 mmt to 1669 mmt.
In the commercial sector, emissions increased from 781 mmt to 1046 mmt.

Through 2006, total U.S. energy-related carbon dioxide emissions have grown by 17.9 percent since 1990.

The commercial sector has grown the most, 33.9% or 1.8%/year. The residential sector has grown by 25.6% or 1.4%/year. The transport sector has grown 25.4% or 1.4%/year. The industrial sectors decreased .9% over the period, or .01%/year.

Both the commercial and the residential sectors are dominated by electricity. 2006 emissions from the electric power decreased 46.4mmt (2%) and generation decreased by .1%.

Energy Information Administration

Comment:
We have a lot of work ahead of us. If the U.S. were to ratify the Kyoto treaty, we would be committed to reducing our emissions to 7% below our 1990 levels. Many scientists are recommending that we reduce our emissions by half by 2055, or basically avoid emitting 200 billion tons of carbon, or 7 billion tons/year, worldwide. However, increasing appliance and lighting efficiency in all buildings to Energy Star standards could reduce total emissions by 1/7 the amount needed.

Fans vs. AC

Straight from Mr. Electricity himself:
A window unit AC uses 500 to 1440 watts, while a 2.5-ton central system uses about 3500 watts. That's a lot of energy. A floor fan uses only 100 watts on the highest speed, and ceiling fans use only 15 to 95 watts depending on speed and size.

Comment: Michael Bluejay, aka Mr. Electricity, runs a site devoted to saving electricity. Green Factoid has spent many happy hours on his site, literally spellbound by his wealth of technical data: the site can only be described as nirvana for the factoid loving.

As far as fans and ACs go, here are a few numbers. We currently pay about $.18/kWh. So a single 1000w air-conditioner costs the seemingly low $.18/ hour. Running that AC 24/7, however, would cost us a not-so-modest $130/month. Using the same numbers, with central, you will pay $.63/hour and $453/month.

While no one but my father runs their AC round the clock (and his is central!), in our profligate days we would often run three ACs at a time to cool our apartment. That could easily add up to more than 24/7 use in July and August, especially since I work at home during those months.

One the other hand, running a 100 watt fan for the same period costs less than .02/hour and a whopping $13/month. Ceiling fans are even less.

Playing with a Calculator #2: Appliance Emissions

For those who like Wonky sites, check out the "Carbon Dioxide Information Analysis Center"--yes there is such a center--which is part of the Oak Ridge National Laboratory for the Department of Energy. The site is a factoid lover's dream.

From their site:
Q. How much CO2 is emitted as a result of my using specific electrical appliances?

A. For this answer, we refer you to an excellent article, "Your Contribution to Global Warming," by George Barnwell, which appeared on p. 53 of the February-March 1990 issue of National Wildlife, the magazine of the National Wildlife Federation. The article, assuming that your electricity comes from coal, calculates CO2 emissions corresponding to the use of various electrical appliances. For example, one hour's use of a color television produces 0.64 pounds (lb) of CO2, and each use of a toaster produces 0.12 lbCO2, whereas a day's use of a waterbed heater produces 24 lb CO2.

In general, the coefficient is about 2.3 lb CO2 per kilowatt-hour (kWh) of electricity. You can calculate the kWh of electricity by multiplying the number of watts (W) the appliance uses times the number of hours (h) it is used, then dividing by 1000. For example a 60-W light bulb operated for 24 h uses

(60 W) x (24 h) / (1000) = 1.44 kWh.

This use of electricity would produce an emission of

(1.44 kWh) x (2.3 lb CO2 per kWh) = 3.3 lb CO2

if the electricity is derived from the combustion of coal.

Carbon Dioxide Information Analysis Center

Green Factoid has spent long hours, calculator in hand, fooling around with these equations. For example, our 1998 side-by-side GE fridge is rated at 71kwh/month or 852 kwh/year. That equals about 1960 lbs./year. Send Green Factoid some of your own calculations.

Should you go Carbon Neutral?

A lot of companies are advertising that they are “carbon neutral” and Al Gore’s site among others suggests that individuals calculate their impact and then buy offsets based on the number they get. There is obviously not much to debate if the purveyors of offsets are crooked, but assuming we are buying from legitimate “offsetters” the question still remains: do we think this is a good idea?

It does feel a little like a cocktail party conversation topic rather than a true solution: after all, how many people are really going to buy these? Enough to actually be useful? On the other hand, I can understand why big shots who have legitimate reasons to, say, fly hundreds of thousands of miles or people in the public eye who worry about their green credentials might want to buy some bragging rights/peace of mind, a la Richard Branson. However, I can’t say I think any number of offsets could ever excuse a 20,000 square foot house—I mean, really, how much space can one family possibly need? Ditto driving massive gas-guzzlers.

An argument I find more compelling concerns experimenting with and developing the market itself. I am convinced that we will need a variety of different solutions: voluntary, mandatory, market, government, industrial, residential. It is worth testing the market for offsets, if only to measure the levels of public commitment to voluntary solutions.

Personally, I will have to do more research to see if I think offsets give an adequate environmental bang for my buck—versus just giving the money to the Sierra Club or planting some trees. As far as Green Factoid is concerned, the highest priority for everyone should be curbing their own energy use. So screw in those CFL bulbs, turn off that A/C, and then rejoice in the savings on your electricity bill, and as a bonus, should you choose to go that route, you will have less emissions to offset.

For More Information:
Environment Defense has an excellent article discussing the principles behind carbon neutrality, the usual (mostly specious) arguments advanced against it, and recommendations for some legitimate places to buy offsets.

Carbon Offsets Count

Electricity Factoid Month

Since the northeast is expecting its first day of +90° weather, and I have finally turned on my (new energy-star) air-conditioner, I will kick off Electricity factoid month.

These numbers are a few years old, but the percentages should hold up.

U.S. HOUSEHOLD ELECTRICITY CONSUMPTION
Electricity consumption by 107 million U.S. households in 2001 totaled 1,140 billion kWh. The most significant end uses were central air-conditioning and refrigerators, each of which accounted for about 14 percent of the U.S. total.

From the Energy Information Administration


The EIA is part of the Department of Energy and is a goldmine for factoid-addicted environmentalists.

Recycled Toilet Paper

Seventh Generation sure does love its factoids:

If every household in the U.S. replaced just one 4-pack of 260 sheet virgin fiber bathroom tissue with 100% recycled ones, we could save:

* 988,200 trees
* 2.5 million cubic feet of landfill space, equal to 3,700 full garbage trucks
* 356 million gallons of water, a year’s supply for 2,800 families of four
* and avoid 60,600 pounds of pollution!

Seventh Generation

Product Review: We have been trying out their recycled paper toilet paper (I can barely bring myself to write, let alone say, the phrase "bathroom tissue") which is made from an impressive 80% post-consumer paper. It’s a pretty decent product: the phrase “fluffy as a cloud” does not exactly leap to mind, Charmin style, but neither does “sand paper.” Their paper is nice and sturdy and comes in hefty double rolls that last much longer than some of the earlier types of recycled TP. My only problem is that it is not cheap.

Energy Star Pledge Update

From the Energy Star site today:

533,814 People Have Taken The Pledge

Collectively, we have pledged to change 1,129,886 bulbs. That means we will avoid using 318,627,852 kWh of energy, prevent 502,799,270 lbs of greenhouse gas emissions, and save $31,862,785 in energy costs. You're making a difference!

Comment: In the month since I took the pledge myself, 10,000 more people have pledged to change another 100,000 bulbs, reducing emissions by another 39,500 tons. Companies like Home Depot, GE, and Sylvania are running campaigns. Energy Star is right: we are making a difference.

Take the Energy Star Pledge

Playing with a Calculator #1: the Sierra Club's 2% solution

Continuing from the previous post: The Sierra’s Club’s 2% solution--reduce your emissions 2% a year for 40 years--seemed too good to be true, and at first I thought there was something hinky with their numbers, especially when I took our first-year number, 270 lbs, and multiplied it by 40, yielding 10,800 lbs: that seemed absurdly easy, but then I realized that only tells us the reduction of the final year. Since we are currently reducing by a lot more than 270 pounds, the number I really wanted is the total number of pounds over the whole period. Using an all-too-human process of rationalization, I figured that if we accelerate our reductions, we will not have to reduce by as much later in the 40-year period.

What Sierra Club doesn't make explicit is that they are using an arithmetic progression. To compute it with round numbers, let’s say 2% for you equals 100 lbs of CO2 emissions. The first year you reduce by 100, the next by 200, then 300, and so on until in year 40, you have to reduce by 4000 lbs. Arithmetic progression has its own cool factoid concerning Carl Friedrich Gauss, whose teacher asked his third-grade class to calculate the sum of the numbers 1-100. The 10 year old child immediately popped out with the answer, 5050.

For those of us who still struggle with calculating 15% tips, the formula is:

N(a1 + an)/2=Sn

Again with our example:

40(100 + (100 x 40)/2=82,000

or a total of 82,000 pounds over the whole period.

Our family’s number was 270 lbs, so our 40-year total is 221,400 lbs. That averages to a 2.76 ton reduction each year—roughly 40%.

The old faithful, Wikipedia, has a helpful explanation of the formula, including the Gauss factoid.

The Sierra Club’s 2% solution

From their web site:
The world's scientists agree: Global warming is real, here, and happening faster than anyone predicted. But scientists also say we can curb global warming and its consequences -- if we take bold, comprehensive action now that adds up to an 80 percent cut in carbon emissions by 2050. That's a do-able 2 percent cut a year for each of the next forty years.

The Sierra Club’s 2% solution


Comment: 2% is quite modest when you think about it—at least in the beginning. If we start with our “Al Gore” base-line rate of 6.75 tons or 13,500 pounds of emissions, we would only have to reduce our use by 270 pounds a year, about the equivalent of one CFL light bulb. On the other hand, by the end of our 40 year period, our emissions will have to be a meager 2700 pounds, a reduction of 5.4 tons per year.

Just changing to wind energy reduced our emissions by 1.9 tons a year—a 28% reduction. Luckily for us renewable energy is an option in New York. Changing our light bulbs and getting serious about turning lights off has reduced our electricity use by about 20%. Unfortunately, these two reductions somewhat cancel each other out. If we added a car as efficient as the Toyota Prius, we would reduce our emissions from our base line by 50%.

Getting started

It is helpful to establish a base-line so you can keep track of your progress. Al Gore’s site allows you to calculate your current emissions. It is worth seeing how your family stacks up against the average. According to the calculator, we emit 6.75 tons/year, which is “average.” However, when I switched us to 100% renewable electricity, our impact went down to 5.3 tons, “smaller than average.” If we drove a Toyota Prius instead of a Honda Odyssey, it would go down to 3.3 tons—very tempting. On the other hand, if we drove a Range Rover it would leap up to 8.5 tons--more than the Hummer!

It is also worth it to keep track of your electricity bills so you can see how many kWh you generally use in a month. Then as you put in place energy savings measures, you can see if your hours go down. Our energy savings measures have had a definite pay-off. Our average daily usage is down by about 5 kWh, which works out to about $30 per month.

Calculate Your Impact

Compact Fluorescent Bulbs: Factoid #2

If every American home replaced their 5 most frequently used light fixtures or the bulbs in them with ones that have earned the ENERGY STAR, we would save close to $8 billion each year in energy costs, and together we would prevent the greenhouse gases equivalent to the emissions from nearly 10 million cars.

Energy Star

Aluminum: Factoid #1

It takes 19 times more energy to manufacture an aluminum can from raw materials than from recycled aluminum.

The average aluminum can goes from store shelf, to scrap heap, and back to the shelf in 42 days.

Ben Jervey, The Big Green Apple.

Bamboo Clothing?

It is hard to believe that one of the world’s hardest woods (really a grass) can produce beautiful fabric. More importantly, in contrast to pesticide-intensive cotton, bamboo is easily grown without chemicals.

More factoids about Bamboo from Bamboosa:
Bamboo is of the world's most prolific and fastest-growing plants, and is able to reach maturity in about four years, compared to the typical 25 to 70 years for commercial tree species in the U.S.

Bamboo is nature's most sustainable resource, is grown without pesticides or chemicals, is 100% biodegradable, and naturally regenerative. Bamboo is actually a tropical grass, with an extensive root system that sends out an average of four to six new shoots per year, naturally replenishing itself and growing to heights of 60 feet or more. Some bamboo species grow up to 4 feet per day and can be harvested every 3 to 4 years.

Why Bamboo? on Bamboosa


Product Review:
I bought socks and a tee shirt from Bamboosa, an online retailer of Bamboo clothing. I must say the socks are the softest and most comfortable I have ever worn—at $10 a pair they are competitive with high-end socks like Therlos. The tee shirt has a beautiful drape and sheen, somewhat like top-quality rayon, but the fabric is more breathable and soft. Lands End also sells Bamboo bath towels that are rated a best buy by the Wall Street Journal.

Definitely check out Bamboosa: Bamboosa