Thursday, October 16, 2008

Carbon Footprint of a MacBook

I have called for carbon labeling on all products and Apple has taken up the challenge. With their new MacBooks, they have released an environmental report (thanks to Earth2Tech for the pointer) that specifies how much CO2 is emitted in the production and use of the laptops.

Over the 4 year lifespan of a MacBook, it is responsible for 460 kg of CO2 emissions (115 kg per year). At 8.8 kg of CO2 per gallon of gasoline, that is equivalent to the emissions of 52 gallons (13 gallons a year). 115 kg is just .6% of the average American's 20,000 kg of co2 emissions a year.


As the chart shows, 50% of the life cycle emissions of a MacBook come from the production and manufacturing of the device (230 kg). Unfortunately there is no additional information as to what the main contributors to this value were.

Another 10% (46 kg) of the emissions come from the transportation of the laptop. That is the equivalent of 5 gallons of gasoline, which seems like a lot for a 10 lb device. I looked at one carbon offset program for shipping that assumed .08 lbs of co2 per ton mile shipped. At 1/200 a ton, this would mean that the laptop was shipped 253,000 miles or 32 times around the Earth. How far are they shipping these laptops?

39% (180 kg) of the emissions come from producing the electricity needed to run the laptop for 4 years (45 kg per year). Not clear what kind of assumptions they made for how many hours a day the laptop was operating or what the source of the electricity was.

One of the easiest ways for a consumer to reduce their carbon footprint is to wait longer before upgrading their computer. Using a MacBook for an extra year would bring the 5 year emission total to 510 kg (an addition of 45 kg), lowering the annual amount to 102 kg, a savings of 13 kg a year.

The yearly emissions of a MacBook are fairly similar to that of mobile phone based on this study that I looked at. The production of a mobile emitted 60 kg of CO2 and the usage another 52 kg for a total of 112 kg of CO2 a year (the study assumed that the phone is replaced after a year). That is almost identical to the 115 kg a year that using a MacBook generates.

The MacBook's co2 emissions equivalent to 52 gasoline gallons is a bit less than the 64 gasoline gallons of energy equivalent that a computer and monitor used over their lifetime based on this study I previously looked at (50 gallons for the manufacturing of the computer and 14 for the usage over 4 years). They aren't completely comparable as the other study just gives energy usage and not CO2 emissions.

I hope more computer manufacturers follow Apple's lead and publish the carbon footprint of the machines they manufacture.

7 comments:

Kip HT said...

Shipping:

Keep in mind the fuel required to transport all of the individual components to be assembled.

Or maybe they just made a pretty graph to get the gullable to believe that they are saving the world by buying a mac...

Fat Knowledge said...

Kip,

From the report:
Includes the extraction, production, and transport of raw materials; and
the manufacture of the product as well as product packaging.

Transport: Includes air and sea transportation of the finished product and its
associated packaging from the manufacturing site to continental distribution hubs.


I believe that the fuel required to transport all of the individual components to be assembled is included in the analysis.

Kriti Bhargava said...
This comment has been removed by the author.
Anonymous said...

Sir,
We are IIT Bombay(India)Students, working on a reasearch project (How green is your e-mail)in which we have to estimate the carbon footprint of sending the e-mails. We'll be grateful if you can provide us with some sites that can help us in calculating it for the infrastructural requirements of sending an email.

Thanks
Regards

Kunal Gupta
kunalgupta@iitb.ac.in

Anonymous said...

Very interesting how Apple now publishes c02 emissions from their products. How comparable do you think the energy intensity and C02 emissions of producing an iMac versus that of a standard Dell pc are?

Fat Knowledge said...

I don't know how different an iMac is versus a Dell PC. I would think fairly similar as I think their internals are more or less the same, but I really don't know.

lifay said...

You have to consider the corresponding weight of the truck, not just item.

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