In Shell’s latest energy scenario, Sky, dealing with emissions from aviation – airplanes – falls into the category of what are called the ‘hard to abate’ sectors. These are activities for which there is no immediately obvious pathway to significantly reduce emissions of carbon dioxide. While emissions could be reduced through making aircraft more efficient, the problem is that more people are taking more flights. And so, the growth in demand cancels out the efficiency gains and there is no absolute reduction in emissions. Only a reduced increase.

Nevertheless, aviation forms part of the broader net zero emissions story in Sky, so how is this achieved?

Planes are dependent on hydrocarbon fuels that can produce great heat and power in relatively small quantities. Although there is some work in progress to develop electric planes for short flights, this is not the technology that emerges in Sky.

What the Sky scenario suggests is that first advanced biofuels begin to make their way into aviation. These fuels replace the hydrocarbon fuels derived from oil. Advanced biofuels can be considered near carbon-neutral provided robust land management practices are in place. But by 2070, when Sky reaches net-zero emissions, biofuels are less than 50% of the aviation fuel mix.

Over the longer-term, there is a technology shift. In Sky we imagine that this could result in planes powered by hydrogen.

In Sky, a first intercontinental hydrogen plane flies in the 2040s and investment scales up in the 2050s. The reason it takes so long is that there is very little research and development activity today.

So while aviation turns to new fuels and technologies the rate of change for this challenging sector is not fast enough for zero emissions by 2070. Rather, aviation makes use of the emergence of carbon sinks, or technologies that can remove carbon dioxide from the atmosphere. In Sky, the principal carbon sink is the combination of bioenergy with carbon capture and storage (CCS), also known as BECCS.

When energy crops for biofuels are grown they absorb carbon dioxide from the atmosphere. Typically, this carbon dioxide is returned to the atmosphere when the energy product is consumed. But if the carbon dioxide is captured and stored, then this achieves a net removal of carbon dioxide from the atmosphere, a carbon sink.

The aviation sector can use sinks to reach net-zero emissions long before technologies and fuels are available to deliver a non-emitting sector.

Such sinks would be purchased through the carbon trading market, such as the sector is starting to do under CORSIA (Carbon Offsetting and Reduction Scheme for International Aviation), developed and agreed by the International Civil Aviation Organization (ICAO). It’s a long haul for aviation, but Sky shows what is technically possible, but still very challenging to achieve.



Read the Sky publication to see how the goals of the Paris Agreement could be met through a combination of technology, government policy and societal actions.

Could society achieve the goals of the Paris Agreement? What do you think? Share your thoughts on social media tagging @Shell and using #ShellScenarios.

This post is part of Shell scenarios ‘could the world achieve Paris’ series.

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Download Sky Scenario

The Sky scenario illustrates a technically possible, but challenging pathway for society to achieve the goals of the Paris Agreement.

Could society achieve the goals of the Paris Agreement?

Discover the Sky scenario through our latest content series, twelve questions addressing key topics found within Sky.

Shell and the energy transition

Shell scenarios are not the Shell business plan nor a policy proposal. To find out what Shell is doing to thrive through the energy transition click here.

For over two decades Shell scenario thinking has incorporated the issue of climate change. The Sky scenario joins two previous Shell scenarios, Mountains and Oceans that saw rapid decarbonization but fell short of the goals of the Paris Agreement. To achieve the goals of the Paris Agreement, the Sky scenario relies on a complex combination of mutually reinforcing actions by society, markets and governments. It adopts an approach grounded in current economic and policy development mechanisms, but then progressively becomes ‘goal-driven’ to achieve society’s ambition for net-zero emissions by 2070. At Shell, we hope it’s a helpful contribution to one of the world’s toughest challenges. You can explore all three scenarios at

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