The true true size of Africa

The true true size of Africa
Nov 10th 2010, 17:52 by G.D.
(The Economist) LAST month Kai Krause, a computer-graphics guru, caused a stir with a map entitled “The True Size of Africa”, which showed the outlines of other countries crammed into the outline of the African continent. His aim was to make “a small contribution in the fight against rampant Immappancy”—in particular, the fact that most people do not realise how much the ubiquitous Mercator projection distorts the relative sizes of countries.
A sphere cannot be represented on a flat plane without distortion, which means all map projections distort in one way or another. Some projections show areas accurately but distort distances or scales, for example; others preserve the shapes of countries but misrepresent their areas. You can read all the gory details on Wikipedia.
Gerardus Mercator’s projection, published in 1569, was immediately useful because it depicts a line of constant bearing as a straight line, which is handy for marine navigation. The drawback is that it distorts the shapes and areas of large land masses, and the distortion gets progressively worse as you get closer to the poles. (Africa looks about the same size as Greenland under the Mercator projection, for example, even though it is in fact 14 times bigger.) This was not a big problem for 16th-century sailors, of course, and the Mercator projection remains popular to this day.
In Mr Krause’s map (above) he seems to have used the shapes of the countries from a Mercator projection, but has scaled up the outline of Africa, without changing its shape, to show the appropriate area. An alternative and arguably more rigorous approach would be to repeat the exercise using an “equal area” projection that shows the countries’ areas correctly while minimising shape distortion. These two properties are the hardest to balance when showing the whole world on one map. I decided to rework Mr Krause’s map using Gall’s Stereographic Cylindrical Projection (1855) with two standard parallels at 45°N and 45°S. Distortions are still evident at the poles, but for most countries shape is maintained, and their areas are shown correctly. As you can see (below), the results are distinct from Mr Krause’s map. But however you look at it, his point is a good one: Africa is much bigger than it looks on most maps.

Equal Earth projection
The Equal Earth map projection is a new equal-area pseudocylindrical projection for world maps jointly developed by Bojan Šavrič (Esri), Tom Patterson (US National Park Service), and Bernhard Jenny (Monash University). It was created to provide a visually pleasing alternative to the Gall-Peters projection, which some schools and socially concerned groups have adopted out of concern for fairness. Their priority is to show developing countries in the tropics and developed countries in the north with correctly proportioned sizes.

2025

15 August
African Union joins calls to end use of Mercator map that shrinks continent’s size
Member states back Correct the Map campaign that urges governments and organisations to use more accurate map
The African Union has backed a campaign to end the use by governments and international organisations of the 16th-century Mercator map of the world in favour of one that more accurately displays Africa’s size.
Created by the cartographer Gerardus Mercator for navigation, the projection distorts continent sizes, enlarging areas near the poles like North America and Greenland while shrinking Africa and South America. “It might seem to be just a map, but in reality, it is not,” the African Union Commission deputy chair, Selma Malika Haddadi, told Reuters, saying the Mercator fostered a false impression that Africa was “marginal”, despite being the world’s second-largest continent by area, with more than 1 billion people. The union has 55 member states.
Criticism of the Mercator map is not new, but the Correct the Map campaign led by the advocacy groups Africa No Filter and Speak Up Africa has revived the debate, urging organisations to adopt the 2018 Equal Earth projection, which tries to reflect countries’ true sizes.
Correct the Map wants organisations such as the World Bank and the UN to adopt the Equal Earth map. A World Bank spokesperson said it already used the Winkel tripel projection or Equal Earth for static maps and was phasing out Mercator on web maps.
The campaign said it had sent a request to the UN geospatial body, UN-GGIM. A UN spokesperson said that once received it must be reviewed and approved by a committee of experts.