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First select your home city,
then select your flight destinations.

Flight Emission Map
Help

To select a city:

  1. On a computer with mouse/trackpad, hover over the city and click when the name is visible.
  2. On a touch screen, first tap to see the city name, then tap again to confirm.

The site shows a world map centered at a place selected by the user.

Destinations are selected and emissions for selected flights are displayed. Select several times for multiple flights to the same destination.

All selected flights disappear when a new centre is chosen.

So what?

You have probably already noted that domestic or regional flights typically cause less than 1000 kg of CO2e emissions, while intercontinental flights range from 2000 kg up to 6000 kg.

So what?

There is good reason to be very concerned about these emissions:

CO2e emissions are causing climate change.

Combatting climate change is probably the biggest challenge facing humanity. Preventing disastrous effects caused by global temperature increase will require major efforts and will affect us all.

  • To limit the temperature increase to 1.5ºC, the latest report from IPCC concludes that annual CO2 emissions will need to start decreasing rapidly immediately and reach 3 tonnes per person globally by 2030, roughly halving emissions within a decade. For the rich world, which starts from much higher emissions, the rate of decrease must be even faster.
  • Allowing for a 2ºC increase gives a little more leeway, but even this goal poses unprecedented challenges.

Emissions from flying and how to reduce these is one part of this puzzle, where individual attitudes can exert pressure on politicians to act and where individual behaviour affects the outcome.

Main takeaways from this site

  • One annual intercontinental flight is unsustainable.
    It is impossible to reconcile such emissions with the drastic reductions in overall emissions that will be necessary. To go on holiday also by air will remain possible and important, but the current trend of rapidly increasing flight emissions must be reversed. In fact, 2000 kg of annual emissions from flying is far from being in line with the 2ºC target.
  • When planning a holiday, always consider alternatives with shorter travel for a similar experience.
    The emissions from a flight are roughly proportional to its length. Flying three times as far results in three times as high climate impact, etc. The map can be used to find alternatives with less climate impact. Of course, such alternatives may involve replacing air travel with train, bus or car.
How are emissions computed?

The numbers presented on the map are based on research by Larsson & Kamb [1,2]. They find a global average CO2 emission of 90 g per person km, caused by burning fossil fuel. In addition, greenhouse effects are caused by so-called non-CO2 emissions, including contrails (water vapour) and emissions of aerosols (small particles). These effects are short-term but potent. The scientific certainty for how to treat the non-CO2 emissions is very low, but we use the best current estimates [3], which suggest that one should add a further 90% to the CO2 emissions to account for these effects. This gives a total emission of 170 g per person km in CO2 equivalents.

Emissions from a particular flight depend on many factors, such as type of aircraft, flight length and altitude, weather conditions, cabin factor, etc. One important factor in the context of this map is how emissions vary with distance. Long distance flights typically have lower emissions of CO2 per passenger km than shorter flights, since an aircraft emits less CO2 per km while cruising than during take-off. On the other hand, a larger share of the long-distance flight is conducted at altitudes high enough to cause significant non-CO2 effects, resulting in higher non-CO2 emissions per passenger km. Short distance flights may on the other hand not even reach high enough altitudes to cause significant non-CO2 effects. Therefore, the additional 90% non-CO2 emissions described above is an underestimate for longer flights and an overestimate for shorter flights. As such, these two effects cancel each other out to some extent and the resulting CO2-equivalents per passenger km are on average similar regardless of distance.

Many flight emissions calculators are available online. In [1], several of these are compared. There are differences, but most calculators end up with CO2e emissions well in line with the figures used here.

The emission estimates shown are for direct flights. For multi-leg itineraries, they certainly underestimate the real emissions. Considering this and the uncertainties described above, we want to emphasize that the emission numbers we show are not as precise as they may seem. However, they give a relatively good estimate of the magnitude of the emissions from air travel.

References

  1. Kamb, A., Larsson J. (2019) Climate footprint from Swedish residents' air travel, Chalmers University of Technology. Also available in Swedish: Kamb, A., Larsson J. (2018) Klimatpåverkan från svenska befolkningens internationella flygresor 1990 – 2017, Chalmers University of Technology.
  2. Larsson, J., Kamb, A., Nässén, J., Åkerman, J. Measuring greenhouse gas emissions from international air travel of a country's residents. Methodological development and application for Sweden, Environmental Impact Assessment Review 72 (2018) pp. 137-144.
  3. Lee, D. et al. Transport impacts on atmosphere and climate: Aviation. Atmospheric Environment 44 (2010), pp. 4678-4734.
Making images of maps

The maps are built in Scalable Vector Graphics, which means that map images can be scaled arbitrarily without any decrease in quality in form of pixelation. Of course, the coastlines and country boundaries do not have infinite precision, but map images can be enlarged substantially, e.g. to poster size, with excellent results. The key to achieving the best possible quality is to avoid as long as possible converting the image to bitmap formats such as JPEG or PNG. Note also that the maps on touch devices have lower resolution.

The recommended way to proceed is as follows:

  • Save the map as a PDF file, using the browser's Print functionality. Check in the preview that the image you want fits on a page and is not obscured by e.g. the info panel or +/- buttons. Don't worry if the whole world is visible and your intended image is small at this stage. PDF can accommodate vector graphics and the file can be scaled up later.
    Unfortunately, the placement of the map in the print file is not exactly as on screen, so this may take some iteration.
  • Crop the PDF file to get the image you want. There are many tools that can do cropping, e.g. Adobe Acrobat and MacOS Preview. There are also free online services that offer cropping, but some of these are of dubious quality.
  • In many cases the cropped PDF file is just what you want as final result. In others, you may need to convert to a bitmap format as a last step; make sure you get enough pixels for your purpose. Again there are many tools that can do this step.
Customizing the map

For particular purposes, the map can be further customized by adding information to the URL ("the web address"). As an example, we might want to display a map with the following non-standard parameters:

  • The centre is at Halmstad in southern Sweden, at latitude 56.67 degrees North and longitude 12.86 degrees East, which is not on the map.
  • The emissions per person km are set to 160 g. (Note that we recommend not to change the default value unless you know better, but this is to show what is possible.)
  • The map is clipped at a radius of 15000 km from the centre (so the whole earth is not visible, even when unzooming).

The URL to get this map is http://flightemissionmap.org/#Halmstad/56.67,12.86/160/15000 where we have added a fragment to the URL, starting with the character #. This extended URL can be used in bookmarks or links and will then generate a map with these particular parameters. Also change of centre done using the map will be added to the URL and thus reflected in bookmarks or links.

Spaces within a city name must be encoded with %20, as in Los%20Angeles. Non-ASCII characters must also be URL-encoded, as in G%C3%B6teborg (for Göteborg). There are many free online encoders that can do this for you.

Embedding the map in other sites.

The map can be embedded in an iframe on a HTML page. The same type of URL is used, extended with a hash fragment, which sets all parameters. As an example, the following HTML code will result in a map frame of 800x600 pixels, centered at London, using the default value for emissions and clipping the map at 12000 km.


    <iframe width="800px" height="600px"
       src="http://flightemissionmap.org/#London/51.51,-0.13/170/12000">
    </iframe>

As the reader has already guessed, the latitude of London is 51.51 and the longitude -0.13 degrees.

About the map projection

The maps we generate use a projection (the equidistant azimuthal projection) with the following properties:

  • Each of the red lines follows a great circle and thus shows the shortest route from the centre to the destination. Also, the initial direction from the centre is correct (as an example, by centering the map at New York, one can observe that the shortest route from there to Hanoi is to go straight north, via the north pole).
  • All the red lines (or more generally, all lines through the centre) are in the same scale, i.e. a route which is twice as long on the map is also twice as long in reality, etc. This is further illustrated by the circles showing flight distances causing emissions of 1000, 2000,... kg.

    It should be noted that lines that do not pass the centre do not have these nice properties. They can be considerably elongated, in particular close to the edge of the map.The extreme case is the circle that forms the border of the map at radius 20000 km; all the points on this circle correspond to one point in the real world: the antipode of the centre, i.e. the exact opposite point on the globe.

You may recognize the initial map. A slight variation, with the North Pole in the centre, is what is used in the logotype of the United Nations.

About this site

The site is developed and maintained by Björn von Sydow in collaboration with Jörgen Larsson and Anneli Kamb at Chalmers University of Technology, Sweden.

The site is built using D3.js, with map data from Natural Earth.

You can contact us at bjorn@flightemissionmap.org.

The site should work well on a laptop or desktop computer using any major browser. It can also be used on touch devices, even though the lack of hovering and the small screen of phones make the experience less fluent.



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