Aircraft contrails account for 2% of humanity’s contribution to climate change

Contrails contribute to climate change.
Contrail – image: MikeB

Contrails are responsible for the equivalent of 2% of humanity’s entire contribution to climate change. To put that another way, contrails are responsible for 60% of the aircraft industry’s greenhouse effect i.e. the aircraft industry’s contribution to climate change.

I bet you didn’t know that those pretty contrails trailing behind airliners high in the sky were contributing so substantially to global warming. For the sake of clarity, ‘contrails’ is a word which stands for “condensation trails”. They are made up of clouds of ice crystals from the aircraft’s exhaust fumes which freeze in wet, cold air.

In humid conditions, contrails can become white patches of cloud cover. These are known as ‘contrail cirrus’. They linger for hours and they trap heat in the atmosphere which has risen from the ground below.

Contrails have a bigger effect on global warming than aircraft fuel emissions.


But the good story today as reported in The Sunday Times (my thanks) is that the problem is easy to rectify. This begs the question as to why it hasn’t been done earlier!

The solution to the problem has been found by a Cambridge-based start-up company called Satavia. This is a tech company founded in 2013 by an atmospheric scientist whose name is Adam Durant. He believes that a mere 5% of aircraft flights cause 80% of the global warming due to contrails.

He also believes that by adjusting the altitude of these flights by just a few hundred feet will eliminate the global warming problem.

This is because the atmospheric conditions under which the clouds of ice crystals form are only present in a very thin layer of atmosphere called “ice supersaturation regions”. They cover vast areas but they are not thick if you visualise them as a layer of atmosphere.

As a consequence, if the aircraft flew above them or below them there would be no contrails.

We specialise in forecasting weather vapour. We start with the best available weather forecast at the beginning of the day, when the airlines start their flight planning

Adam Durant

The flight plans of aircraft are uploaded to Satavia’s system where they are tweaked if they across or enter supersaturation regions. The companies running the airliners don’t have to do anything except follow the new flight plan.

Etihad has been testing the technology for about 12 months. They are talking with Satavia regarding a 10-year contract. And Satavia have been working with other airlines such as KLM and That emirates.

There may be another benefit for the airlines and it’s a commercial one in which they can present their green credentials because the impact of changing these routes is now recognised by a not-for-profit organisation called Gold Standard. This is an organisation which quantifies and certifies climate interventions and they’ve started drawing up certificates for its use.

This means that airlines can use Satavia’s technology and trade them on the carbon market. The European Union emissions trading system is going to include contrails by 2027. This will mean that airlines flying in the European Economic Area will be obliged to record their impact.

Climate change and animal conservation

Also, for the sake of clarity, global warming or climate change is perhaps the single biggest threat to the survivability of countless numbers of species of wild animal and indeed the human-animal. Even today, at the beginning of the severe signs of climate change we are seeing massive wildfires and floods, both of which kill millions of animals.

Last year, huge wildfires killed over an estimated billion animals in Australia. These fires single-handedly destroying years of conservation efforts by the Australian’s who are hellbent on shooting feral cats as a means to protect small marsupials mammals. They would do better to stop digging up coal and selling it to China which contributes to global warming and indirectly those nasty wildfires.

Two useful tags. Click either to see the articles: Speciesism - 'them and us' | Cruelty - always shameful Note: I will donate 10 cents to an animal charity for every comment made over the next three months on pages where comments can be made.
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