Over the same two decades, global air travel doubled growing to four trillion RPKs (revenue passenger kilometers).

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But the relative proportion of total fuel use can be extrapolated by comparing passenger kilometers traveled versus tonne-kilometers for freight on the top 10 carriers.

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They worry more about tornadoes (130 deaths a year) than crossing the street (2, 708 deaths), more about commercial jets (0.03 deaths per 160 million passenger kilometers) than about driving at night (16, 480 deaths a year between 8 p.m. and 4 a.m.).

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