A fairer map? Why the US said no

(Edited and refined by Bai Kelei, with the assistance of AI translation.)

On 4 September, the United Nations (UN) General Assembly adopted, by an overwhelming majority, a resolution led by Togo, advocating the use of the Equal Earth projection for drawing maps. The resolution received 164 votes in favour, one against and six abstentions. It said maps drawn using the Equal Earth projection developed in 2018 more accurately represent the relative sizes of the continents and would help to correct decades of distorted perceptions about the size and importance of Africa and other regions.

The US was the sole country to vote against it, apparently believing that it alone saw the matter clearly while everyone else was mistaken. The truth is that the vote has broader political, social and technological considerations. It also does not mean that maps based on the established Mercator projection can no longer be used. Furthermore, China adopts a unique approach.

500-year illusion

In 1569, Dutch cartographer Gerardus Mercator created a world map using what is now known as the Mercator projection. On this map, all meridians are drawn as parallel vertical lines. In geometry, a straight line crossing parallel lines forms the same angle with each one. As a result, a straight line drawn across a Mercator map represents a constant direction. For navigators, this made it remarkably easy to plot a vessel’s course: they could simply draw a straight line at the desired angle and follow it. This practical advantage helped make the Mercator projection the standard for navigation for centuries.

However, the Mercator projection inflates land areas closer to the poles, while those nearer the Equator are relatively compressed. As a result, the US, Europe and Russia, which are located at high latitudes, appear extraordinarily large. The greatest visual illusion is that Greenland appears to be as large as Africa, when in fact it is only one-fourteenth of Africa’s area.

In 2018, three scientists — Bojan Šavrič, Tom Patterson and Bernhard Jenny — developed the Equal Earth projection to accurately reproduce the proportional areas of the continents. On maps produced using this method, areas near the Equator, including Africa, Latin America and South Asia, appear substantially larger, while the US, Europe and Russia look smaller.

On the day of the UN vote, Togolese Foreign Minister Robert Dussey said that a fair map would not change the world’s geography, but how people viewed the world. He said the matter concerned cognitive justice, historical memory and equal dignity, and urged wider adoption of the Equal Earth projection.

The US surprised many by becoming the only country to oppose the resolution. US President Donald Trump — the “king of knowledge” (懂王 dong wang), as Chinese netizens call him — who believes he is always right, has reasons to both support and oppose the Equal Earth projection.

Greenland, Trump and geopolitical pride

Trump has long wanted to acquire Greenland. If he supported the Equal Earth projection, Greenland would appear on maps as a much smaller, more barren patch of land — and perhaps attract less international opposition to a US takeover.

However, from the perspective of making America great again, it also makes sense to support the continued use of Mercator maps. If the US were to occupy Greenland, it would gain an area as large as Africa and appear to have expanded its territory greatly, filling Americans with pride.

The US also highlighted what appears to be a more scientific argument. Although Mercator maps are distorted, they preserve the shapes of landmasses, and a straight line between any two points on it represents a rhumb line. This makes them the most suitable base maps for civil aviation, maritime navigation and map-navigation software like Google Maps. They are not only accurate for navigation, but also practical.

Moreover, the Mercator projection is the most computationally efficient mathematical model most aligned with digital applications, including satellite remote-sensing and Web Mercator tiled maps. Web Mercator tiled maps are the cornerstone of modern online maps. Google Maps, Amap, Baidu Maps, Apple Maps and web-based basemaps are all founded on Mercator projection technology.

No map is ever perfect

But the Equal Earth projection also has undeniable scientific value. From an evidence-based perspective, it is an equal-area projection that fully conforms to reality. Maps drawn using this projection depict accurate continental areas, making them highly suitable for presenting scientific and macroeconomic data such as global population density, climate change and resource distribution.

Equal Earth projection maps also have shortcomings as they sacrifice shapes and angles to ensure that relative country sizes are accurately represented. Consequently, continental outlines can be severely distorted along the edges of the map and in high-latitude regions.

It should be acknowledged that no perfect map exists since no projection can simultaneously represent areas, shapes, angles and distances accurately. The strengths of the Mercator projection and Equal Earth projection are in angular accuracy and area precision respectively, making them suitable for different purposes. There is also a compromise approach.

China uses neither the Mercator nor the Equal Earth projection to produce world maps, but a standard polyconic projection — a distinctive variant developed with its own intellectual property. China’s standard polyconic projection was independently developed in the mid-20th century by Zeng Shiying, a renowned Chinese cartographer and academician of the Chinese Academy of Sciences, together with experts from China Cartographic Publishing House. Maps based on this projection represent a potential third path between “fairness in area” and “proper shape”. It neither adopts the visually radical tendency of the Equal Earth projection to excessively tilt continental edges nor retains the Western-centric approach of the Mercator projection.

The UN resolution is more than a debate over mapmaking technology, but also who gets to define history, knowledge and culture, and who has the discursive power to determine international rules. It encourages member states to use equal-area map projections in educational materials and public publications, and is advisory rather than binding.

As a giant in global technology and digital mapping, the US naturally opposes the Equal Earth projection. It certainly would not want the existing, deeply entrenched technological ecosystem and commercial standards, led by itself and Europe, to be disrupted by a UN political resolution.

Since the matter is contentious and both the Mercator and Equal Earth projections have their own merits, it would be better to use each according to practical needs. Alternatively, there is the option of emulating China in adopting a middle path.

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