Dr. Mohamed E. Hereher

Assistant Professor, College of Arts and Social Sciences

If we look at a world map, we tend to consider it as a representation of the real world. The continents appear in their familiar locations, countries are delineated by defined boundaries, and therefore we tend to assume that their sizes, shapes, and spatial relationships accurately represent geographical reality. But does the world really look the way it appears on these maps? The scientific answer is: not exactly. This is because a flat world map is not a photographic representation of the Earth's surface; rather, it is a mathematical model designed to represent a three-dimensional surface on a two-dimensional plane. The mathematical process through which this transformation is achieved is known as a “map projection”. The fundamental challenge is that a curved surface cannot be transformed onto a flat plane without introducing some degree of distortion in one or more spatial properties, including area, shape, distance, direction, or angle. In order to understand this distortion, imagine an attempt to peel an orange and flatten its entire peel onto a table. It would be impossible to make the curved peel completely flat without tearing, stretching, or otherwise deforming parts of it. This simple analogy provides an effective understanding of the fundamental principles underlying map projections. Consequently, the appropriate scientific question is not: “What is the best map projection?”, but rather: “Which map projection is most appropriate for the purpose for which the map is being produced?”

Map projections can be classified according to the spatial properties they are designed to preserve. Some projections preserve local angles and shapes to a high degree but do not preserve area. The Mercator projection is the best-known example of this category. Other projections preserve the correct proportional relationships between areas. They are consequently more appropriate for thematic maps representing population, land cover, urban expansion, land use, and other phenomena for which area is an important analytical variable. The Equal Earth projection is an important example of this group. Other projections preserve accurate distances from specified points or along particular lines. The Azimuthal Equidistant projection, for example, can preserve distances from the centre of the projection. Similarly, certain Azimuthal projections can preserve directions from a specified central point, making them particularly useful for applications involving directions, routes, and polar regions.

So, why does the world look the way it does on maps?  The answer is closely associated with the historical prominence of the Mercator projection, one of the most influential projections in the history of cartography. Developed by Gerardus Mercator in 1569, during a period of expanding maritime navigation and geographic exploration, the projection preserves local angles and directions. These characteristics made it particularly valuable for navigation. However, these advantages come with distortions in another spatial property: the area. In the Mercator projection, areal distortion increases progressively with latitude. As one moves away from the Equator toward the poles, the apparent size of geographical areas becomes increasingly exaggerated. Consequently, regions located at high latitudes appear substantially larger than their actual relative sizes. The most widely known example of this distortion is the comparison between Africa and Greenland. On Mercator maps, Greenland may appear large and can visually seem comparable in size to Africa. In reality, however, Africa has an area approximately 14 times larger than Greenland.

One important modern alternative is the Equal Earth projection, which is particularly useful when the accurate representation of area is a primary objective. It is an equal-area projection designed to represent the world while preserving the correct proportional relationships among geographical areas and, at the same time, providing a visually balanced representation of the Earth's landmasses. When moving from a Mercator representation to an Equal Earth projection, viewers may initially be surprised by the different appearance of the world. Africa and South America appear relatively larger, while the visual prominence of Greenland is substantially reduced. The continents themselves have not changed; rather, the mathematical framework through which they are represented has changed. Equal Earth is therefore particularly appropriate when area constitutes an essential component of the cartographic message. However, it is not regarded as the optimal projection for navigation, engineering surveys, or every form of spatial analysis.

What Motivated the United Nations General Assembly to Reconsider Conventional World Map?

The fundamental scientific concern underlying this reconsideration of conventional world-map representation is that the Mercator projection does not preserve area. Consequently, the widespread use of Mercator for general-purpose world maps can produce a misleading visual impression of the relative sizes of continents and countries. Using an equal-area projection such as Equal Earth for applications in which relative area is important provides a representation in which the proportional sizes of continents are maintained accurately.

The development of Geographic Information Systems (GIS) has fundamentally transformed the way geographers and cartographers work with map projections. Modern GIS technology makes it possible to reproject millions of geographical features between different coordinate reference systems efficiently. More importantly, it allows researchers to select an appropriate projection for a particular application, geographical region, or even a specific stage of a research project. For example, a researcher investigating urban expansion may employ an equal-area projection when calculating and comparing urban land areas. Similarly, when producing a global map intended to compare the relative sizes of countries or continents, the researcher may select Equal Earth or another suitable equal-area projection. GIS has therefore shifted the emphasis away from searching for a single universal projection toward selecting projections according to the geographic and analytical requirements of each application.