GoKawiilPeople have long projected their known worlds on maps. This depiction, from Gerardus Mercator’s copy of Geography by Claudius Ptolemy, dates back to second-century Alexandria, Egypt. Credit: Royal Geographical Society via Getty
A view of the world that has prevailed for around 450 years has been challenged. On 4 September, the United Nations General Assembly voted to phase out use of the Mercator map, a sixteenth-century projection that is widely used but has been criticized for not representing countries’ sizes accurately.
The UN resolution instead endorses use of the Equal Earth projection, which better shows the relative sizes of land masses. That’s an important step towards correcting biases in the Mercator map, researchers say, even though that projection will still be useful in some scientific applications.
“Changing the projection used for global representation has geographic, educational and symbolic significance,” says Melinda Laituri, a geographer at Colorado State University in Fort Collins.
Projection preferences
The Mercator projection, presented by Flemish cartographer Gerardus Mercator in 1569, shows the meridians as straight lines — allowing for easy navigation with compasses. It gained popularity from the eighteenth century, at a time of increased European maritime expansion and became the go-to map for governments and classrooms the world over. Most web-based map services, including Google Maps and MapQuest, adopted it.
But critics point out that it shows the Northern Hemisphere as disproportionately large, because it increasingly stretches land masses — nearly 70% of which are north of the Equator — the closer they get to the poles. For example, Canada and Russia seem much larger than they really are. And Greenland and Africa seem to be similar sizes even though Africa’s area is about 14 times larger than Greenland’s.
That’s problematic, say researchers, because people are inclined to conflate size and importance. “Maps don’t simply identify the location of places. They also exist as social texts which influence how we imagine the importance, centrality or peripheral position of places,” says Derek Alderman, a geographer at the University of Tennessee in Knoxville.
“The effect of the Mercator projection on people’s mental map of the world is difficult to quantify. It was a common assumption among cartographers that the Mercator projection has strong cultural influence and may be doing irreparable damage to our ability to think accurately about the world,” says Bernhard Jenny, a cartographer at Monash University in Melbourne, Australia, and co-creator of the Equal Earth projection. Jenny cites a research article from 2009 showing that map readers don’t tend to compensate for distortions even when they know they exist1.
Because all maps are projections from the 3D globe onto a 2D surface, they inevitably distort shapes, distances, areas and directions. The Equal Earth projection, developed in 2018, shows the relative sizes of land masses more accurately than its Mercator counterpart does by curving the meridians (see ‘Bent into shape’). However, this affects some shapes and angles, notably in New Zealand, which is stretched diagonally and sits on the edge of the map.
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