Mercator Projection

Uses and Misuses of the Mercator Projection

The World Bank is not the only organization to misemploy the Mercator projection for basic world maps. In a Google image search of “world map,” roughly a third of the initial set of maps returned greatly inflate the high latitudes. Not all, however, grotesquely exaggerate Greenland; one particularly unsightly map, reproduced above, solves the problem by erasing the island. The most egregious misuse of the projection is perhaps found in television newscasts in the United States. Here Mercator’s world image seems to serve as an icon of global breadth, adding gravitas, if counterfeit, to the stories of the day. The image is so emblematic of respectability that a caricature version is employed by the satirical Daily Show. In the image above, a gargantuan Canadian archipelago crowns Jon Stewart. Note as well the attenuated and misshapen depiction of India, the slug-shaped Japan, and the numerous non-existent land bridges.

The Mercator projection was designed by its creator for shipboard use, the title of the original map telling us as much: Nova et aucta orbis terrae description ad usum navigantium emendate et accomodata (“new and improved description of the world amended and intended for the use of navigators”). Critical thinkers have long noted the absurdity of using Mercator projections for general purposes. In 1943, the New York Times opined that, “We cannot forever mislead children and even college students with grossly inaccurate pictures of the world.”* Yet mislead them we still do, although to a lesser extent than in the mid-twentieth century.

That is not to say, however, that the only appropriate uses of the projection are navigational. Google Maps, for example, employs Mercator’s perspective because it retains the correct shape of landmasses at any scale of resolution. (Or, as the Wikipedia puts it, “Despite its obvious scale variation at small scales, the projection is well-suited as an interactive world map that can be zoomed seamlessly to large-scale (local) maps, where there is relatively little distortion due to the projection’s near-conformality.”) As a result, Google Maps are quite serviceable for local or regional uses, but at the global scale they are worse then useless, depicting Ellesmere Island (population 146) in the Canadian arctic, for example as roughly the same size as Australia.

A considered defense of the Mercator projection is found in Andrew Taylor’s The World of Gerard Mercator: The Mapmaker Who Revolutionized Geography (2004, Walker & Company, New York). The book is well written and well researched, recommended to anyone interested in the history of cartography. Taylor’s vindication of his subject’s famous projection, however, is poorly considered. He embraces the Mercator projection for general purposes essentially because it is widely embraced: “It is Mercator’s map that appears on schoolroom walls, in diaries and magazines, and, most important of all, in peoples’ minds. That approval is the ultimate democracy” (p. 255). Such claims are extraordinarily anti-intellectual; if nonsense is widely held, we are told, it should be celebrated, as anything else would be an anti-democratic insult to the will of the people.

Epistemological populism, which equates truth with popularity, is a rare and extremist stance. It is difficult to imagine its claims being made so boldly in fields other than geography. When it comes to geography, however, lower standards often apply.

*The quotation is from Andrew Taylor’s book, referenced above.

The World Bank’s Development Base Map: A Cartographic Fun-House Mirror

The World Bank provides global data on many issues other than the “ease of doing business.” The Bank’s website offers a treasure-trove of statistics on wide array of topics. All data is mapped out by country, providing a virtual atlas of world development. Whether the data are accurate and the maps illustrative are different matters. Although the Bank trumpets the quality of its information, there are good reasons to remain guarded, as we saw last week with the Business Index. When it comes to the World Bank’s cartography, there is no doubt whatsoever: the maps are so bad as to be amusing. They distort the word just as a fun-house mirror distorts a human body, grotesquely shrinking one part and magnifying another. As a result, they are as useful for depicting geographical patterns as sideshow mirrors are for personal grooming.

I selected “Internet Users (Per 100 People)” for no particular reason; all of the cartography on the Bank’s website uses the same base map and hence looks much the same. The signal flaw is the selection of the Mercator projection, which grossly exaggerates the area of the high latitudes. Not that there is anything wrong with the Mercator projection per se; it is actually a brilliant and practical devise, generating the only maps on which a constant compass bearing can be plotted as a straight line. Gerardus Mercator devised the projection in 1569 for navigational uses, never intending that it would be used for general-purpose maps. I can only imagine that he would be horrified at the way his eponymous map is misused today.

Leftist scholars have long criticized the Mercator projection for exaggerating the size of Europe relative to the tropical realm. One would have no idea from examining the map, for example, that DR Congo is roughly ten times the size of Britain. From the perspective of the academic left, the Mercator projection is Exhibit A in the charge of Eurocentrism that it levels against the Western mapping tradition.

Such charges of cartography bigotry may convey an element of truth, but they are greatly overdrawn. The Mercator projection inflates the size of northern Russia and Greenland much more than it does that of Western Europe, yet no one has made accusations of “Russo-Greenlandic-centrism.” If anything, the World Bank is Antarctocentric; its magnification of Antarctica is extreme, as most Mercator maps of the world cut off at 75 degrees south latitude or so, thus excluding much of the polar continent. The World Bank makes no such an allowance. As the second map posted above shows, it portrays Antarctica as roughly the same size as Eurasia, Greenland as larger than South America, and Alaska about two-thirds the size of the contiguous United States.

The use of the Mercator projection is the most glaring problem with the map, but many others can be found. Why do eastern Eurasia, Australia, and New Zealand appear twice? Such duplication, along with the Mercator distortions, reduces the area that actually carries information – the part inside the blue rectangle – to less than half of the map. Why, we might also ask, is extreme eastern Siberia apparently appended to North America? (Note how even Wrangel Island is divided, half of it colored on one side of the map, the other half colored on the other side.) Why are French Guiana and Reunion not mapped with France, even though they are as much parts of France as Hawaii and Alaska are parts of the United States? Why are the areas disputed between India and China unmapped, unlike all other disputed regions? Why do the data tables used to make the map claim to cover “countries,” yet actually includes a number of non-sovereign entities that are almost never so classified? (Or, to put it in other worlds, why are New Caledonia and Puerto Rico mapped as if they were countries, but not American Samoa or French Polynesia?) Why are Russia’s arctic islands mapped with Russia, while Norway’s Svalbard is left blank? In all cases, no information is provided about such maneuvers, and no sense is made.

Why does the World Bank deploy such monstrous maps? I suspect the main reason is one of simple geographical illiteracy. The Bank hires competent statisticians and computer programmers, but they evidently know little about the world, and virtually nothing of cartography. Higher-level employees at the Bank are either equally clueless or simply do not care that their organization grotesquely misrepresents the world.

All such problems pertain to the World Bank’s base map, used to depict all of its data. In regard to the internet map posted above, questions can also be raised about both the reliability of the data and their cartographic portrayal, as will be explored in the next Geocurrents posting.