Equal Earth projection

Short description: Pseudocylindrical equal-area map projection

Equal Earth projection. 15° graticule. Imagery is a derivative of NASA’s Blue Marble summer month composite with oceans lightened to enhance legibility and contrast. Image created with the Geocart map projection software.

The Equal Earth map projection is an equal-area pseudocylindrical global map projection, invented by Bojan Šavrič, Bernhard Jenny, and Tom Patterson in 2018. It is inspired by the widely used Robinson projection, but unlike the Robinson projection, it retains the relative size of areas. The projection equations are simple to implement and fast to evaluate.[1]

The features of the Equal Earth projection include:[2][3]

* The curved sides of the projection suggest the spherical form of Earth.
* Straight parallels make it easy to compare how far north or south places are from the equator.
* Meridians are evenly spaced along any line of latitude.
* Software for implementing the projection is easy to write and executes efficiently.

According to the creators, the projection was created in response to the decision of the Boston Public Schools to adopt the Gall–Peters projection for world maps in March 2017, to accurately show the relative sizes of equatorial and non-equatorial regions. The decision generated controversy in the world of cartography due to this projection’s extreme distortion in the polar regions. At that time, Šavrič, Jenny, and Patterson sought alternative map projections of equal areas for world maps, but could not find any that met their aesthetic criteria. Therefore, they created a new projection that had more visual appeal compared to existing projections of equal areas.[3][4][5][6]

As with the earlier Natural Earth projection (2012) introduced by Patterson, a visual method was used to choose the parameters of the projection. A combination of Putniņš P4ʹ and Eckert IV projections was used as the basis.[1] Mathematical formulae for the projection were derived from a polynomial used to define the spacing of parallels.

## Contents

* 1 Formulation
* 2 Use
* 3 References
* 4 External links

## Formulation

Equal Earth projection distortion, using the Tissot indicatrix at 10° intervals.

The projection is formulated as the equations

x=23λcos⁡θ3(9A4θ8+7A3θ6+3A2θ2+A1)y=A4θ9+A3θ7+A2θ3+A1θ

where

sin⁡θ=32sin⁡φA1=1.340264, A2=−0.081106, A3=0.000893, A4=0.003796

and φ refers to latitude and λ to longitude.

## Use

The Equal Earth compared to similar equal-area pseudocylindrical projections.

The first known thematic map published using the Equal Earth projection is a map of the global mean temperature anomaly for July 2018, produced by the NASA’s Goddard Institute for Space Studies.[7]

The Correct the Map campaign, backed by the African Union and the Caribbean Community, has called for the wider adoption of the Equal Earth projection as an alternative to the Mercator projection.[8]

## References

1. ↑ 1.0 1.1 Šavrič, Bojan; Patterson, Tom; Jenny, Bernhard (2018-08-07). "The Equal Earth map projection". International Journal of Geographical Information Science 33 (3): 454–465. doi:10.1080/13658816.2018.1504949. https://www.researchgate.net/publication/326879978.
2. ↑ "Equal Earth projection". http://shadedrelief.com/ee_proj/.
3. ↑ 3.0 3.1 Morales, Aurelio. "La nueva proyección Equal Earth: todo lo que debes saber" (in es). Valladolid: MappingGIS. https://mappinggis.com/2018/09/la-nueva-proyeccion-equal-earth-todo-lo-que-debes-saber/.
4. ↑ "Equal Earth: un mapamundi más preciso que muestra el tamaño real de África" (in es). N+1. August 22, 2018. https://nmas1.org/news/2018/08/22/mapa-equal-earth-ciencia.
5. ↑ "Equal Earth: Idean un nuevo mapa del mundo basado en un mapa del 1569" (in es). Código Oculto. https://codigooculto.com/2018/08/equal-earth-idean-un-nuevo-mapa-del-mundo-basado-en-un-mapa-del-1569/.
6. ↑ "Colección cartográfica - La proyección Equal-Earth" (in es). visionscarto. https://visionscarto.net/la-proyeccion-equal-earth.
7. ↑ "NASA GISS on Twitter" (in en). Twitter. https://twitter.com/NASAGISS/status/1029769823167963136.
8. ↑ Demony, Catarina; Bior, Ayendeng (2025-08-15). "African Union urges adoption of world map showing continent's true size". Reuters. https://www.reuters.com/world/africa/african-union-urges-adoption-world-map-showing-continents-true-size-2025-08-14/.

## External links

* Official website

* v
* t
* e

Map projection

* History
* List
* Portal

By surface

| Cylindrical|

| Mercator-conformal|

* Gauss–Krüger
* Transverse Mercator
* Oblique Mercator

|

Equal-area|

* Balthasart
* Behrmann
* Gall–Peters
* Hobo–Dyer
* Lambert
* Smyth equal-surface
* Trystan Edwards

* Cassini
* Central
* Equirectangular
* Gall stereographic
* Gall isographic
* Miller
* Space-oblique Mercator
* Web Mercator

Pseudocylindrical|

* Eckert II
* Eckert IV
* Eckert VI
* Equal Earth
* Goode homolosine
* Kavrayskiy VII
* Mollweide
* Sinusoidal
* Tobler hyperelliptical
* Wagner VI
* Winkel I and II

Conical|

* Albers
* Equidistant
* Lambert conformal

Pseudoconical|

* Bonne
* Bottomley
* Polyconic
* American
* Werner

Azimuthal
(planar)|

| General perspective|

* Gnomonic
* Orthographic
* Stereographic

|

* Equidistant
* Lambert equal-area

Pseudoazimuthal|

* Aitoff
* Hammer
* Wiechel
* Winkel tripel

By metric

| Conformal|

* Adams hemisphere-in-a-square
* Gauss–Krüger
* Guyou hemisphere-in-a-square
* Lambert conformal conic
* Mercator
* Peirce quincuncial
* Stereographic
* Transverse Mercator

|

Equal-area|

| Bonne|

* Sinusoidal
* Werner

|

Bottomley|

* Sinusoidal
* Werner

Cylindrical|

* Balthasart
* Behrmann
* Gall–Peters
* Hobo–Dyer
* Lambert cylindrical equal-area
* Smyth equal-surface
* Trystan Edwards

Tobler hyperelliptical|

* Collignon
* Mollweide

* Albers
* Briesemeister
* Eckert II
* Eckert IV
* Eckert VI
* Equal Earth
* Goode homolosine
* Hammer
* Lambert azimuthal equal-area
* Quadrilateralized spherical cube
* Strebe 1995

Equidistant in
some aspect|

* Conic
* Equirectangular
* Sinusoidal
* Two-point
* Werner

Gnomonic|

* Gnomonic

Loxodromic|

* Loximuthal
* Mercator

Retroazimuthal
(Mecca or Qibla)|

* Craig
* Hammer
* Littrow

By construction

| Compromise|

* Chamberlin trimetric
* Kavrayskiy VII
* Miller cylindrical
* Natural Earth
* Robinson
* Van der Grinten
* Wagner VI
* Winkel tripel

|

Hybrid|

* Goode homolosine
* HEALPix

Perspective|

| Planar|

* Gnomonic
* Orthographic
* Stereographic

|

* Central cylindrical

Polyhedral|

* Cahill Butterfly
* Cahill–Keyes M-shape
* Dymaxion
* ISEA
* Quadrilateralized spherical cube
* Waterman butterfly

See also

* Interruption (map projection)
* Latitude
* Longitude
* Tissot's indicatrix
* Map projection of the tri-axial ellipsoid

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