A Qatar Airways Airbus plane takes off from Vienna airport on February 28, 2020. -

JOE KLAMAR / AFP

  • How can the airplane be used in a world constrained by the need to reduce greenhouse gas emissions?

    The think-tank The Shift Project and the Supaero-Decarbo collective are examining the question in a report published on Wednesday.

  • Their first proposal: to establish, based on the work of the IPCC, a carbon budget for the aviation sector, that is to say a quantity of greenhouse gas emissions not to be exceeded by 2050. .

  • The Shift Project and Supaero-Decarbo looked at whether the promises of technological progress for greener planes would be enough not to exceed this carbon budget.

    Or if it should go through a reduction in traffic.

Will we be able to fly in 2050?

The issue is not only whether the aviation sector will be able to recover from the worst crisis in its history, in which the health crisis linked to the coronavirus is plunging it *.

Because in the longer term, it is faced with another dilemma: that of climate change to which it contributes, recall the think-tank The Shift project, which is considering a low-carbon economy, and Supaero-Decarbo, a collective of engineers from the aeronautics that reflects on greener aviation.

Already set a carbon budget

In 2018, global civil aviation emitted 2.56% of global CO2 emissions **.

It is little, say its defenders, but not negligible so far.

Above all, the explosion in traffic planned before Covid-19 raised fears of a worsening of its carbon impact.

The International Air Transport Association (IATA)

predicted a doubling of world traffic over the next twenty years, reaching 8.2 billion passengers in 2037, against 4.1 billion in 2017. The coronavirus epidemic may be an opportunity to start afresh on new bases, compatible with the Paris Agreement on the climate and the need to limit global warming to + 2 ° C by 2100. This is the whole proposition of the report published on Wednesday by The Shift Project and Supaéro-Decarbo.

This already involves defining a carbon budget for air transport.

"That is to say a quantity of CO2 emissions not to be exceeded until 2050 and that an international body, such as the International Civil Aviation Organization (ICAO), would be responsible for enforcing, says Grégoire Carpentier, co-founder with Olivier Del Bucchia of Supaero-Decarbo.

This is what is missing today.

"

The IPCC estimates at 1,170 gigatonnes (GtCO2) *** the global CO2 emissions quota not to be exceeded, between 2018 and 2100, to contain global warming below + 2 ° C.

All sectors combined.

“From there, we estimated a carbon budget for the aviation sector calculated in proportion to its CO2 emissions in 2018, explains Grégoire Carpentier.

This gives us a budget of 21.6 GtCO2 over the period 2018 to 2050. ”

Insufficient technological progress?

If no improvement is made to planes to reduce their emissions and if traffic regains growth of 4% per year from 2024, the expected rate before the crisis, "then this budget will be consumed from 2034", indicates Olivier Del Bucchia , specifying that this scenario is however unlikely: "There is a perpetual improvement of devices, including in terms of energy efficiency."

In their report, The Shift Project and SupaéroDecarbo studied two scenarios of decarbonization by technology in the aviation sector.

The “Maverick” scenario, very optimistic, and the “Iceman”, more realistic.

- / The Shift Project

It remains to be seen whether the promises of green aircraft will allow this limit of 21.6 GtCO2 to be met.

To do this, the report looked at a very optimistic scenario, called “Maverick”.

Here, traffic growth will recover to 4% per year from 2024, as Iata projected before the crisis.

At the same time, this scenario relies on the entry into service of short and medium-haul hydrogen-powered aircraft from 2035, as announced by Airbus.

Or, on the same date, a long haul that can fly with 100% alternative fuels (biofuels).

“In this scenario, the aircraft fleet is renewed every fifteen years, compared to twenty-five on average at present, and the production of alternative fuels is beyond all current projections and is 100% dedicated to aviation, ”adds Olivier Del Bucchia.

Verdict?

Even “Maverick” does not manage to stay below 21.6 GtCO2 by 2050. The budget would be exceeded by 2041. In the second scenario, considered more realistic ***, this budget would be fully consumed by 2038.

Focus on reducing traffic growth

In other words, technological progress will not be enough to be in the nails of the Paris Agreement.

“A first option would be to increase the carbon budget allocated to global civil aviation,” says Grégoire Carpentier.

But that would imply doing so to the detriment of other sectors.

"

The second ?

Focus on reducing traffic growth.

This is the whole battle of environmental NGOs in recent years and even more since the health crisis linked to the coronavirus.

The Shift Project and Supaero-Decarbo are also moving in this direction.

The report identifies four measures that could be deployed in the short term.

It is in particular the densification of the cabins [boarding more passengers by plane by removing places in "business" class to increase those in eco class], the limitation of business aviation, or the fact of rethinking the system. “miles” so as not to encourage theft of opportunity.

The report adds the abolition of air offers when a rail alternative in less than 4h30 exists.

This measure, one of the proposals of the Citizen's Climate Convention, was taken up by the executive in its “Climate and Resilience” bill… but reduced to 2:30.

"It's a start, but the impact is necessarily less," notes Olivier Del Bucchia with a touch of bitterness.

Progressive taxation in a spirit of social justice?

Especially since The Shift Project and Supaero-Decarbo believe that these measures, even coupled with technological progress, will not be enough.

It will be necessary to go further in terms of sobriety… “This involves in particular the full display of the carbon impact of the various transport options,” begins Olivier Del Bucchia.

But we can also imagine relaxation on the taking of holidays [allowing to leave longer but less often], the encouragement of local tourism… ”The authors of the report would also welcome a great citizen reflection on what to do. can and should aircraft be used in 2050 in a low-carbon world?

In other words, why use it?

What uses should be prioritized?

Once this reflection is mature, The Shift Project and Supaéro-Decarbo propose to associate it with adequate regulations.

Here again, several avenues are open: limitation of airport slots to regulate activity, work on the ticket price signal [by prohibiting tickets at discounted prices as Austria does?], Taxes, even if not very popular ... On this last aspect, the report identifies “the progressive tax” as an interesting avenue in a spirit of social justice.

“The more we travel by plane and the more distance we travel, the more the amount of this tax increases,” explains Olivier Del Bucchia.

The English are thinking about it.

"

Planet

CO2 emissions from air transport fell by more than 50% in 2020 in Europe

Economy

Coronavirus: Broken prices, smaller planes, redistributed routes… How will the aviation sector be able to reinvent itself?

* The International Air Transport Association (IATA) does not anticipate a return to normal until 2024, with the risk of cascading bankruptcies by then.

** A carbon footprint which is even heavier if we take the non-CO2 effects [condensation trails in particular] but difficult to quantify today.

*** Short and medium-haul hydrogen planes would not be put into service until 2040, just like the first long-haul aircraft running on alternative fuels, and the fleet would be renewed every twenty-five years ...

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