Dr Katie Parker on the UN’s vote to adopt a new world map

The Royal Geographical Society’s Cartographic Collections Manager, Dr Katie Parker, explains the Mercator projection and looks at the UN resolution to formally phase it out. 

Maps have featured prominently in the news lately, largely due to a United Nations resolution encouraging the use of the Equal Earth projection in place of the widely used Mercator projection.  The UN vote to adopt a new world map was primarily to reflect Africa’s true size. But how did the ‘standard’ world map come to be so widely used in the first place? And is there a straightforward way to represent our 2D world on a 2D surface?  

Projections are ways to show the three-dimensional globe as a two-dimensional image. There is no way to flatten the earth, so to speak, without distortion. Imagine you are peeling an orange; it is impossible to remove the rind without ripping it in some way. This ripping, stretching, and displacement is the same thing that happens when cartographers design a projection. 

Projections are designed to answer a specific problem or facilitate a certain task. The Mercator projection debuted in 1569 in a famous world map by its namesake, Gerard Mercator. It was invented to aid navigation, making it easier to sail from one place to another. The genius of the map is that it makes lines of constant bearing into straight lines, thus making a ship’s course easier to plot. It is conformal, or angle-preserving. However, if a projection maintains one aspect, like angles, it usually distorts another. In this case, the Mercator projection exaggerates the size of landmasses in higher latitudes. This makes far northern and far southern landmasses appear much larger than they actually are. 

Over time, use of the Mercator projection in contexts far removed from navigation has cemented a warped view of the world in many people’s minds, suggesting outsized importance for areas that appear larger and at the top of the map – especially  Europe and North America. It is this linking of importance to size and centrality that African nations objected to, as Africa is undersized on a Mercator projection.