• Home
• How does flying contribute to climate change?
• What's the impact of flying?
• Can technology help make planes greener?
• What can I do about it?

Climate modelling

Back to How does flying contribute to climate change?

Scientists are building large global climate models to fit together everything we know so far about the effects of aeroplane emissions and try to predict their future impact. 'Modelling is a bit like a living test tube - we can use the models to try out predictions for the future and see what's likely to happen,' says Helen Rogers, a climate modeller from Cambridge University. 'We rely on atmospheric models to carry out these simulations because we can't just make the change for real and then see what happens.'

Climate experts use real-life measurements and scientific facts about the different emissions to build their state-of-the-art models. They use information from engine manufacturers about how much of each emission is produced, lab-based studies of the chemical reactions that different emissions undergo in the atmosphere, and measurements of the amounts of each emission in the atmosphere.

Scientists feed all the atmospheric measurements taken from balloons and aircraft into their climate models. Image: Cambridge University

Once they've built the climate models they can run them many times over, changing different factors each time to see what impact they have on the environment. For example, they can change information about where an aircraft flies, when it flies, what type of aircraft it is with what sort of emissions, and simulate the effect on the climate. They can also change details about how many planes are flying, simulating past, present and possible future patterns of flying to try and predict what will happen next.

Average aircraft NO_x emissions in 2000 and predicted 2050 emissions as used in the University of Cambridge climate model. Shades of red indicate high areas of emissions and shades of blue indicate lower areas.
Image: Cambridge University/NASA/IPCC

So calculating the true impact of flying on the environment requires a team effort. 'We're currently working with people at the Hadley Centre for Climate Change, trying to incorporate the effect of contrails into their climate models - one of the most sophisticated models in the world,' says Piers Forster, a climate expert at the University of Leeds. 'By working together we hope to improve these models and begin to understand some of the current unknowns about the effects of aviation on climate change.'