Blog by Betsy Mason: “It’s not often that a map projection makes headlines. I have tried and failed to convince editors they are newsworthy. So it’s honestly exciting to see so many stories about the United Nations’ decision to adopt a new map projection. When I heard the news, I thought, “YES! They are ditching the Mercator. Good riddance!” I was pretty sure I knew why.
To understand this decision, it helps to know a little about map projections. Because the Earth is a three-dimensional, round object, all maps have to distort geography in some way to fit that information onto a two-dimensional piece of paper (or your computer screen). Think of cutting open a tennis ball and trying to lay it flat on a table. There are five different aspects of geography that can be distorted to varying degrees during the flattening process: area, shape, distance, direction, and angle. Reducing the distortion of one of these attributes necessarily means increasing the distortion of one or more of the others. A map projection is basically math that dictates how things are distorted. Cartographers choose projections based on the purpose of a map.
(More on map projections—including my favorite, the Armadillo — and how they work in an excerpt from my book All Over the Map below),
The Mercator projection was designed for navigating oceans, so it prioritizes keeping angles and directions between two locations true. To make up for that, it distorts the size and shape of landmasses, making some places (notably Africa) look smaller relative to other continents, and it inflates the size of others (notably Europe and North America). People have argued that this also inflates the perceived importance of northern hemisphere countries relative to countries closer to the equator, which is what I suspected was the reason the U.N. ditched the projection…(More)”.
