AThis peak holiday season, contrails are streaking across the skies and greenhouse gas emissions from international aviation are reaching their highest levels of the year. Emissions of carbon dioxide and water vapor from jet engines are responsible for about 5% of global warming, and studies show that this proportion is rising.
Not surprisingly, rich countries lead the way in most aviation emissions, measured by the airports from which planes take off. The UK, with Heathrow and other international airports, is in third place, behind the US and increasingly wealthy China. Japan is in fourth place, and the United Arab Emirates, with its huge transit airport in Dubai, is in fifth place.
Since less than 10% of the world’s population uses an airplane each year, it is the relatively small frequent flyers who contribute most to emissions.
Not surprisingly, the richest country, the US, with its huge landmass, produces the highest emissions per capita from domestic flights. Australia, whose coastal cities are separated by an often inhospitable interior, is second. Norway, which is wealthy and long and narrow, is third, but the flights were not north-south, but between southern cities. So geography cannot be blamed. It is the wealth of the average citizen that counts.
