Live from Austin!

British Airways gave us the option of paying extra for carbon credits to make up for our air travel. We didn’t take them up on the offer.

There are a number of reasons why I feel carbon offsetting is a bad thing. The first is that by removing the guilt, it encourages people to continue a profligate lifestyle, rather than actually changing their behavior.

For example, if Al Gore genuinely gave a crap about the environment, he would stop flying by private jet so much. But no, he’s rich and can simply buy carbon credits to salve his conscience. Similarly, John Edwards will happily lecture to ordinary people that they should give up their SUVs, then get into his own SUV secure in the knowledge that he’s bought carbon credits to make up for his own indulgence.

(In fact, Edwards owns 3 SUVs — a Ford Escape, a Cadillac SRX, and a Chrysler Pacifica — plus a pickup.)

The second reason why I dislike carbon credits is that there are much more effective ways to reduce emissions. For instance, if British Airways really cared, they would stop painting their aircraft. A fully painted 747 weighs 443kg extra, compared to around 100kg for me plus my luggage. That’s before you factor in the increased wind resistance from cracked and peeling paint, the chemicals needed for stripping and repainting aircraft, and the disposal problem of the dissolved paint and chemicals. [Update: BA could also stop flying empty planes across the Atlantic.]

The third reason why carbon credits are a dubious idea is pointed out by spiked online. When you buy carbon credits for your flight from Climate Care, what you’re actually doing is paying a bunch of Indian families to dig in the dirt via back-breaking manual labor, and pump water manually, rather than using modern farm equipment. Now, it might not be a bad idea if I personally spent some time stomping on pedals to pump water, but I don’t see why Indians should be bribed to do it so I can feel less guilty about air travel.

But my favorite argument against carbon credits is the parody site cheatneutral. If the logic behind carbon credits is really valid, why not buy some infidelity credits and cheat on your partner with a clean conscience?

People often wonder if they should turn their computer off, or leave it on but put it into “sleep mode”. I decided to do some analysis a while back, here are the results.

If you look up the specs, a Sawtooth Power Mac G4 in deep sleep uses about 4 watts of electricity. In MA you pay $0.04823 per kWh, so it costs 4 / 1000 kW * 24 hours * 365 days * $0.04823 = $1.68 per year to leave a Mac sleeping instead of turning it off. So, it’s not going to break the bank.

Heat-wise, conservation of energy tells us that no more than 4W of heat is being emitted by the machine. Compare that to the average human body, which radiates 50-100W (estimates vary, Google if you feel the need to check). So, the G4 isn’t going to heat up the room significantly when it’s asleep either.

What about the environment? Well, let’s assume the worst possible case, that your electricity is all coal-generated. That means emissions are around 0.43kg per kWh of electricity used by the consumer. So in a year of sleep, your Mac would cause the emission of 15kg of CO2. Sounds pretty bad, doesn’t it? Well, according to space research you produce 1kg of CO2 per day by breathing, or a massive 365kg per year. So the Mac is 20x better for the environment when asleep than you are.

What about the hardware? Well, in deep sleep almost all the hardware is powered down exactly as if the machine was turned off. The hard drive, which is the piece most likely to wear out, is powered down. The CPU and RAM are incredibly unlikely to wear out even if you run them 24×7 for the next ten years, at which point the machine will be so obsolete it’s worthless. So turning the Mac off won’t make it last any longer or protect your ‘investment’.

So, I conclude that there is absolutely no economic or environmental need to turn your Mac off. If you have a UPS, you may as well leave the Mac asleep when you’re not using it.

Of course, if your computer is a PC which doesn’t have an Energy Star “deep sleep” mode, the above calculation may be off by a factor of 10 or more. However, most PCs are now Energy Star.