I hope that the view that Mercator’s projection is “the world’s most popular map” is incorrect (Editorial, 22 August). Most modern world maps show distributions; relative densities are what matters. Equal-area projections are required, and using Mercator for such purposes is geographical illiteracy. With digital data and computer programs, many different equal-area projections are at everyone’s fingertips: cylindrical, azimuthal, conic – and oblique or recentred versions of any.
Geographers were using these long before the Peters projection and Equal Earth were promoted. Shape distortion can be reduced by intersecting the Earth at two standard parallels or meridians, or by interruption – as in the widely used gores of the universal transverse Mercator projection. Projections can be focused on any area of interest: the best for Africa could cut the Earth at two standard parallels (10 and 30 degrees east), or a 2,000km radius circle centred somewhere around the Central African Republic. But any map boundary is unreal.
