The Gall-Peters projection is an orthographic equal-area map projection of the earth. It was published in 1855 by James Gall in the Scottish Geographical Magazine.
Arno Peters presented the map in 1973 as a 'new invention', and gave it publicity as a better alternative for the Mercator projection, which shows areas very much distorted (showing Greenland somewhat larger than Africa whereas in reality Africa is 13 times as large), because the Gall-Peters projection shows equal areas equal, thus giving the tropics their rightful place on the map. This argument was picked up by many educational institutes and such, and the Gall-Peters projection is therefore in much use.
Professional geographers however, while agreeing with Peters's arguments against the Mercator projection, also find much fault with the Gall-Peters projection because to keep the equal-area, it very much distorts shapes, extending anything near the equator in the north-south, near the poles in the east-west direction. They prefer maps that make a compromise between area and shape accuracy, or that are equal-area with less shape distortion.
Seven North American geographic organizations in 1989 adopted the following resolution that rejected all rectangular world maps, which include both the Mercator and the Gall-Peters projections:
"WHEREAS, the earth is round with a coordinate system composed entirely of circles, andWHEREAS, flat world maps are more useful than globe maps, but flattening the globe surface necessarily greatly changes the appearance of Earth's features and coordinate systems, and
WHEREAS, world maps have a powerful and lasting effect on peoples' impressions of the shapes and sizes of lands and seas, their arrangement, and the nature of the coordinate system, and
WHEREAS, frequently seeing a greatly distorted map tends to make it "look right,"
THEREFORE, we strongly urge book and map publishers, the media and government agencies to cease using rectangular world maps for general purposes or artistic displays. Such maps promote serious, erroneous conceptions by severely distorting large sections of the world, by showing the round Earth as having straight edges and sharp corners, by representing most distances and direct routes incorrectly, and by portraying the circular coordinate system as a squared grid. The most widely displayed rectangular world map is the Mercator (in fact a navigational diagram devised for nautical charts), but other rectangular world maps proposed as replacements for the Mercator also display a greatly distorted image of the spherical Earth."