Cartography is having a moment. First came U.S. President Donald Trump’s clumsy and ire-inspiring attempt to rename Lake Ontario to “Lake America.” Then, more consequentially — though with less fanfare and press coverage — the United Nations adopted a resolution encouraging a shift away from global maps that misrepresent the relative sizes of different countries around the world.

Titled “Correct the map:” rebalancing global cartographic representation and promoting equitable representation of the world’s regions, particularly Africa,” the resolution, brought forward by the Togolese Republic, was adopted by a vote of 163 to one with six abstentions. It will come as no surprise that the United States was the single opposing vote, reflecting the current administration’s apparent aspiration to look bigger on maps.

The resolution takes particular aim at the Mercator map projection, the poster child for a distorted representation of our planet. A map using this projection increasingly swells the land and ocean the further you go from the equator, to the point that Greenland looks about the same size as Africa, even though its actual area is 14 times smaller.

The influence of this inconsistent scaling on people’s mental maps of the world is difficult to know, and studies have not shown conclusive evidence that it causes quantifiable misunderstanding. But as a cartographer, it has always been my conviction that maps work best when they compare apples to apples. When different parts of a single map are built on different assumptions, different methodologies or different scales, the one-to-one spatial and relational patterns people intuitively look for are distorted and ultimately misleading.

What are map projections?

All maps are distortions and abstractions of reality. You can’t render our planet’s three-dimensional spherical surface onto a two-dimensional flat plane without distorting it. And while small distortions occur even in more local maps (say, of a town or a province), at the scale of the Earth, distortions in all spatial properties (size, form, distance and direction) are at their most severe.

Different map projections use different mathematics to transform (or project) our spherical home onto the plane of a sheet of paper or computer screen. Some strive to maintain local shapes and angles (conformal), some aim to maintain true distances between particular locations (equidistant) and some aspire to maintain the true relative size of all parts of the map (equal area). None can achieve all of these aims at once.

Any good cartographer knows that there is no “ideal” map of the world (or of any place, for that matter). Instead, cartographers recognize that good maps are fit for purpose. When charged with making a map, the map-maker must ask, what do we want this map to say? What is the story we want to tell, the impression we want to leave? Answers to these questions guide the long list of choices that must be made, from which map projection to use to what layers of information to include to how to style and design the map.

Mercator vs. Equal Earth