For just three flight paths between Honolulu and the west coast of the USA, changes in wind patterns over the North Pacific could cost an extra US$1.4 million in fuel and result in an additional 4.6 million kg of CO2 emissions per year, reports a paper published online in Nature Climate Change. The authors suggest that if these figures are extrapolated to the global commercial airline industry, annual CO2 emissions could rise by 0.03% of all global CO2 emissions caused by human activities.
Kristopher Karnauskas and colleagues analysed the difference in flight time for roughly 250,000 flights between Honolulu and Los Angeles, San Francisco and Seattle?Tacoma, and compared them with observed daily winds at cruising altitude, to identify the influence of the wind patterns.
They then calculated the response of these winds to greenhouse-gas-induced climate forcing using 34 global climate models. Half of the models predict the extension of the jet exit region into the corridor between Hawaii and the continental US. The researchers calculated that such a change would result in approximately 5.5 additional flying hours per daily round-trip, per carrier, per comparable route; or, extrapolated for four airlines and the probable number of trips, an annual cost of US$1.4 million on fuel and 4.6 million kg of CO2.
The authors also conclude that these changes in circulation have the potential to increase the rate of consumption of fossil fuels by the airline industry (initially by up to a few per cent), feeding back into global climate forcing and resulting in subsequent changes in circulation, and suggest further investigation of the dynamics involved.