Zero-balance aviation still contributes to global warming, study finds

Many net-zero aviation projects fail to take into account the warming effect of cloud trails created by planes, a study has found.

Efforts to make flights greener consider only carbon dioxide emissions, an approach that could ignore 90% of future flights’ contribution to climate change given new findings.

The research, published in Nature Just days after the UK government announced its goal of reducing carbon emissions from flying to net zero by 2050, warns that many strategies designed to decarbonise the aviation sector have significant blind spots.

Currently, the only emissions accounted for by international efforts and most national efforts to decarbonize aviation are those related to the use of jet fuel. In doing so, these standards do not take into account the soot, aerosols and water vapor released by aircraft engines.

Nicoletta Brazzola’s team at ETH Zurich in Switzerland found that, despite these net-zero strategies, the world’s aviation sector could increase global average temperatures by 0.1°C to 0.4°C. C, jeopardizing the Paris agreement to keep the global temperature at 1.5. °C.

“We found that the mitigation efforts needed to bring aviation to a place where it is compatible with the Paris agreement are enormous,” Brazzola said.

The team’s modeling suggested that ignoring the non-CO2 effects of aviation, as most policymakers do, would ignore 90% of future flights’ contribution to climate change. After exploring different future flight demand scenarios, the team also analyzed how much CO2 would have to be removed from the atmosphere by trees or machinery to reach true net zero.

The study showed that, even with a moderate increase in flight demand, the status quo of jet fuel and offsetting would require an area the size of Germany to be planted with trees to offset aircraft emissions. .

“Without a very large reduction in demand and without very rapid, almost unachievable shifts towards clean technologies, we would in any case need to deploy carbon elimination very widely,” she said, expressing concerns. doubts about whether carbon removal projects of this scale would even be feasible.

The findings suggest that the aviation sector’s historic short-term plan to reduce its impact on climate change will not be enough. IInstead of focusing on carbon-neutral aviation, the researchers called for a shift in focus towards climate-neutral solutions.

Some of the solutions that meet this criteria are hydrogen and battery-powered aircraft.

“It would be a drastic change of direction, but I think it’s long overdue,” said Paul Williams of the University of Reading, UK.

Even with all these solutions in place, the study implies that it would be extremely difficult to make the sector truly carbon neutral under the proposed framework without a significant decrease in flight demand.

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Teresa H. Sadler