What mode of transportation is
most environmentally friendly? A paper released online by the
journal Environmental Science and Technology attempts to answer this question. Using a powerful, predictive chemical climate model that takes into
account the effect of a wide range of pollutants, the authors examine
the overall effect on temperature and radiative forcing from a given transport work unit and extend the analysis many years into the future. Turns out, air travel will result
in a lower temperature rise than the equivalent car travel, but only after a long
period of time.

The paper uses as inputs one
year’s worth of emissions from various transportation methods, both
freight and personal. The authors computed the rise
(or fall) in temperature over 5-, 20-, and 50-year
horizons, as well as the radiative forcing impact over 20-, 100-, and 500-year periods.