Discussion of emissions is usually abstract – it is ‘just’ numbers. But numbers are much more accessible when one has a feel for the quantities involved. Volume gives people a much more direct feel for the quantities involved than mass does – it brings the data to life and we get a better feel for how much ‘stuff’ we are talking about.

There are many occasions when abstract visualisations such as graphs that focus just on numbers are appropriate, but there are often considerable advantages in going for ‘concrete’ visualisations. People make sense of the values by relating them to their own bodies, homes, landmarks in their neighbourhood, etc.

From our on-going process of research and development some principles of greenhouse-gas visualisation have emerged:

  • Make it concrete – show actual volumes that gas would occupy
  • Make it true – it should all be to scale
  • Make it as simple as possible – but no simpler
  • Give users something to relate to that is:
    • part of their direct experience (e.g. a known building)
    • personally meaningful (e.g. a landmark or workplace)
    • relevant to the data (e.g. using London buildings to visualise London’s CO2 emissions)

Animated Carbon Quilt Films

These can be produced to tell any ‘carbon story’ with a time factor and will be a major contributor to helping people understand the links between GHGs and their own actions and decisions. We are seeking partners/sponsors for a series of short animated films that could include:

  • How fossil fuel powered industrialization has changed the atmosphere since 1800
  • A visual comparison of ways to attribute responsibility for climate change – current emissions, per-capita emissions, historical emissions, etc.
  • A 400,000 year history of ice ages, sea level changes and the atmosphere
  • How forests and oceans act as ‘carbon sinks’
  • A history of countries and their carbon emissions

All the air in the atmosphere (5140 trillion tonnes) gathered into a ball at sea-level density.

Most viewers are surprised at how small the atmosphere is. Although it extends many thousands of kilometers above the surface of the Earth, the atmosphere gets thin very quickly. 50% of all the air in the atmosphere is found within 5 km of the surface and 90% lies below 16 km. 99.99997% of the atmosphere lies below 100 km up (the official edge of space).

Each person's share of the atmosphere.

If you divided the all the air in the atmosphere into 6.5 billion parts (one for each person on Earth) we'd have nearly 791 thousand tonnes each. This amount of air would fill a cube 870 metres high (pictured here on Bristol, UK).

All the carbon dioxide in the atmosphere.

If you brought it all together, the World's carbon dioxide would fill a cube 116.92 km high. When this picture was made (in 2007) there was 2,989 billion tonnes of carbon dioxide in the atmosphere. The picture shows the volume this amount of the gas would occupy at sea-level pressure and temperature. The blue section is the 'natural' carbon dioxide - the quantity that the Earth has maintained for millions of years. It is vital for all life on Earth. The red section of the cube is the carbon dioxide we have added to the atmosphere (and is still there) since industrialisation began in about 1800.

On average, each American emits as much greenhouse gas every day as 2 British people, 6 Chinese people or 27 Bangladeshi people. American daily per-capita emissions would fill a cube 3 metres high, which means the US adds over 300 million of these cubes to the global total every day.

London's daily carbon dioxide emissions.

139 thousand tonnes of carbon dioxide would fill a sphere 521 metres across.

To most Londoners, '139 thousand tonnes of carbon dioxide' is not a very meaningful quantity. Illustrating it in the context of London landmarks allows viewers to make it meaningful for themselves. The illustration is compelling not just because it is visual, but because we can relate to it on a physical level. Londoners - the primary audience - know what it is like to walk across Tower Bridge, or stand near to the Post Office Tower, and so can 'feel' how big 139 thousand tonnes really is.

Bristol's daily carbon dioxide emissions (6,317 one-tonne cubes)

Bristol's emissions need a Bristol landmark to allow viewers to make the quantity meaningful for themselves. Breaking the quantity up into one-tonne cubes helps the viewer to develop a sense of the scale involved. As viewers, we sometimes struggle to compare volumes, but we are very adept at comparing numbers of things.

One tonne of carbon dioxide gas would fill a sphere over 10 metres in diameter.

Because we can relate to this illustration physically it provides a better sense of scale than the abstract number itself.

One tonne of carbon dioxide gas would fill a cube over 8 metres high.

Because we can relate to this illustration physically it provides a better sense of scale than the abstract number itself. Breaking large volumes up into discrete quantities (such as a number of one-tonne cubes) makes comparison easier. As viewers, we sometimes struggle to compare volumes, but we are very adept at comparing discrete quantities (numbers) of things.

Guardian News & Media's average daily carbon dioxide emissions for 2007/8 (39 one-tonne cubes)

The principle audience for this image was Guardian employees. St Pancras station was chosen as the landmark that provides a sense of scale because the Guardian offices are close to St Pancras. This high view also shows the arched roof above the station platforms. This is a large enclosed volume that viewers are likely to have experienced, and so provides another way to relate to the quantity.

Guardian News & Media's average daily carbon dioxide emissions for 2007/8 (39 one-tonne cubes)

The principle audience for this image was Guardian employees. St Pancras station was chosen as the landmark that provides a sense of scale because the Guardian offices are close to St Pancras.

This low view, from street-level, is more familiar to viewers than the high view, which makes it easier to relate to in some ways.

Daily carbon dioxide emissions from the V&A Museum, Science Museum, Natural History Museum, Royal Albert Hall and Imperial College expressed as streams of one-tonne spheres.

The inset provides a sense of scale for the picture as a whole. The illustration gives a sense of the overall scale of daily emissions and also the rates of the emissions from the different institutions. Such representation lends itself to animation and to real-time 'metering' displays. That is, actual power meters could determine when spheres emerge and so provide real-time feedback.

Volume of carbon dioxide gas emitted by three different 1 km journeys.

This very simple illustration uses the fact that as viewers we are far better at comparing linear dimensions than volumes. We can easily compare the volumes because only one dimension (height) is varying. It would be far harder to compare, say, three cubes or three spheres.

Daily domestic emissions in Bedfordshire, 2006 (actual volume per capita).

Daily domestic emissions in Bedfordshire, 2006 (actual volume per capita).

In this version, domestic emissions have been broken up by fuel into electricity (blue - 45%), gas (green - 48%), heating oil (yellow - 6%), and solid fuel (1%).

It is easy to compare the fuels relatively and absolutely at the same time. The illustration is easy to read because only one dimension (width) is varying, and because the whole from which each 'slice' has been extracted is square.

Volume of carbon dioxide emitted by Stoke Newington School every year.

In the context of special project, year 8 pupils explored ways of expressing their schools carbon footprint in a way that was compelling for them and their peers. Representing the volume as a cube at the site of the school made sense.

The carbon dioxide emitted by Stoke Newington School every year could fill Clissold Park to a depth of 159 cm.

In the context of special project, year 8 pupils explored ways of expressing their schools carbon footprint in a way that was compelling for them and their peers.

The local park is an area all pupils know well. They have a good sense of its size, even if they don't know how many hectares it takes up. Expressing volume in this way gives viewers (those with local knowledge) a strong conception of the quantity involved.

See more examples in the gallery.