Decarbonizing by 2050

The air transportation sector once believed that the best it could do globally speaking would be to reduce its net-carbon output by 50% below 2005 levels by 2050. That view placed the sector out of sync with what the United Nations has called a “global rallying cry” and “race” toward a net-zero economy by 2050. Now, a shift is underway that could sync up the sector with those embracing the more ambitious goal.

For every kilogram of kerosene an aircraft engine consumes, approximately 3 kilograms of carbon dioxide are emitted, according to the International Civil Aviation Organization’s Carbon Emissions Calculator. A large jet engine consumes a kilogram every single second during cruise, so by multiplying this figure with the number of aircraft flying at any given moment, the total emissions escalate rapidly to hundreds of millions of tons per year. During the last decades, carbon that was stored underground for millions of years has been released in vast amounts into the atmosphere, and of that all forms of air, land and sea transport combined account for around one-fifth of global carbon dioxide emissions.

Increasingly, the need for aggressive emissions reductions is being recognized by airlines, airports and others. Europe’s aviation sector unveiled in February its flagship sustainability initiative, Destination 2050. According to this plan, all flights within or departing from the European Free Trade Association, the European Union and the United Kingdom must be CO2 net-zero by 2050, a dramatic step beyond the sector’s global target of a 50% reduction by that year, a goal set by the International Air Transport Association in 2009 and at the time one of the first global commitments by a sector. The catch for the new, more aggressive goal is that flights bound for Europe are excluded for now, but of course this is something that could change if similar commitments are made by the countries of departure. In the United States, the new administration has set the ambitious target of a net-zero economy by 2050, in line with the global climate action under the Paris Agreement. However, it is not clear whether this will be reflected in introduction of even stricter emission goals for air transport in the U.S., similar to the ones in Europe. The stakes are enormous, because it’s far from clear that a 50% reduction in emissions would be enough to meet the climate goal of the Paris Agreement, which seeks as a worst case to hold the temperature rise to below 2 degrees Celsius, while pursuing efforts to limit the increase to 1.5 degrees.

For sure, decarbonizing the whole transportation industry will be an enormous undertaking, including for the air transportation sector. Let’s look at the various paths and trade-offs for reaching net-zero in our sector by 2050.