Air Travel: How Much Global Warming?
Over the past few days, I've been trying to pull together some data on how airplane travel affects global warming, as part of a broader project on transportation and climate change.
My stunningly obvious conclusion: it's complicated. Worse, different calculation methods yield wildly different results.
Take, for instance, this brilliant chart (below) from the Stockholm Environment Institute, comparing many of the major online emissions calculators. Emissions are represented by the light blue lines. As you can see, the online calculators find that a Boston-DC round trip has the impact of somewhere between .19 tons and .48 tons of CO2 emissions, depending on which calculator you use. (By the way -- as I discuss below, it looks like the Atmosfair calculator is probably the most accurate and comprehensive.)
The high-end estimate is over two and a half times higher than the low-end estimate. What's up with that?
