I just rediscovered the Carnegie Mellon EIO-LCA tool, an online model for input-output lifecycle analysis. I ran it for the “Electronic computer manufacturing” sector to see how the results compare with Apple’s lifecycle analysis of my new MacBook.
The result: 284 tons CO2eq per million dollars of output. That translates to 340 kg for a $1200 computer. This is almost the same as Apple’s number, except that the Apple figure includes lifecycle emissions from use, for about a third of the total, so Apple’s manufacturing emissions are about a third lower than the generic computer sector in the EIO-LCA tool.
Directionally, it’s interesting that Apple’s estimate (presumably a process-based accounting) is lower, given that manufacturing happens in China, where electricity and GDP are both carbon-intensive on average. I wouldn’t read too much into the differences without digging much deeper though.