Climate-Neutral Global Aviation – are we on the right track?

Is climate-neutral aviation even possible, what would it look like, and how do we get there?

It is difficult to imagine effective international climate action without making aviation climate-neutral, due to its significant and growing climate impact, and the symbolic value of an activity mostly serving the world’s richest 1% of people using a disproportionate share of society’s resources.

Both major aviation organizations, IATA, representing airlines, and ICAO, representing countries, officially endorse the goal of net zero aviation by 2050. Their past and current actions, however, are not supporting reaching the goal.

This is especially important in today’s context. Biodiversity loss, still growing emissions, food and energy shortages, tense geopolitics including wars, populism, erosion of democracy, inequality – the multiple crises of 2022 (more accurately: multiple symptoms of the same wicked problem), make it easy to lose hope. At the start of COP27 in Sharm El-Sheikh, The Economist declared: Goodbye 1.5°C – Time for some realism, which is of course true if past collective (in)action continues.

In our paper Towards True Climate Neutrality for Global Aviation: A Negative Emissions Fund for Airlines, we explore what action is required for this hard to decarbonize but important sector. We look into all climate effects of flying: over one billion tons of CO2 emitted in 2019, and twice as much again of non-CO2 short-lived but highly potent warming effects, especially contrails and nitrogen oxides (NOx). We also look into the lifecycle impact of alternative fuels, mostly made of biomass, designed to replace kerosene. We examine efficiency levers such as airframes, engines, and load factors. Finally, we analyze negative emissions (NE) projects needed to remove residual CO2 and prevent it from accumulating in the atmosphere, and how to finance and govern such projects.

Past (black) and proposed (green, dotted) passenger-km of global aviation; in yellow CO2 emissions [reproduced with permission from our aviation paper]

To reach the net zero goal of IATA, ICAO, IPCC, and the rest of humanity, we postulate all sectors must reduce their emissions by 90% by 2050. For aviation, this means going from 1 Gt to 100 Mt CO2 per year, by reducing flights to 1.32 trillion passenger-km, or their level in 1984, and improving efficiency by 30%, deploying better airframes and engines, and reaching the average load factor of 90% (from 82% pre-covid). The remaining CO2 would be removed using negative emissions. Flight operators would pay $230 per ton CO2 into a Negative Emissions Fund for Airlines, which would invest $3.3 trillion over 40 years in high-quality carbon removal projects with biodiversity and societal co-benefits.

We do not expect any major technology breakthrough to fundamentally change our analysis before 2050, but would be very happy to revise our assumptions, should such an innovation be proven effective, obtain civil aviation certification, and start worldwide deployment before 2040, allowing time to make an impact.

Finally, while this proposal represents the end of low-cost flights, it is also an opportunity to ensure long-term ecological, societal, and even financial viability for global aviation, re-establishing its Social License. At the same time, it could accelerate the transformation of the whole society towards climate neutrality and ecosystem restoration.  

Join us for a BSL event on this urgent topic, as a contribution to the necessary societal dialogue.

Sascha NICK
BSL Professor