How is air travel impacting the environment?

In August 2019, teenage climate activist Greta Thunberg sailed from Europe to New York to attend a UN climate summit. Her concern over the impact of air transport on atmospheric carbon dioxide levels is shared by an increasing number of environmental campaigners. But just how many planes are in the air at any one time, and where are they going?

Download the free app ‘Flightradar24’ from your app store. If you allow it to access your device’s location, the default app screen shows your local airspace and the presence of any aircraft in the skies around you. If you wait a few moments you will see movement in the aircraft as their flight occurs. Tap on one of the larger aircraft (likely to be an international flight), and an information box opens telling you the flight number, type of aircraft, airport of origin and destination, altitude and speed, and the current and anticipated duration of the flight.

You can get more information on individual flights if you scroll down the left data bar (if you are using a tablet) or select ‘More info’ from the bottom menu (if you are using a phone). By selecting the ‘Speed & altitude graph’ in the information bar you can see a chart showing the variable speed and altitude of that aircraft since departure. Look for two planes that seem to be on a collision course, then look at the altitude for each aircraft and realise how planes occupy 3D space.