Simon Willison created an interactive tool that morphs between the Mercator and Equal Earth map projections. The visualization allows users to drag a slider or press play to watch the world reshape before their eyes. Willison built the animation using D3 after noticing that the Equal Earth projection was recently selected by a UN vote. He asked GPT-6 Astra in ChatGPT Work to generate the code for the transition effect.
The project highlights how artificial intelligence can rapidly produce complex data visualisations that explain abstract geographic concepts. While the Equal Earth projection was chosen for its perceived accuracy in area representation, the tool simply shows the visual differences between standard and alternative views. It serves as a practical demonstration of how AI agents can execute specific technical requests involving mapping libraries.
* The animation runs entirely in a web browser.
* Users can toggle between static and animated modes.
* The Equal Earth projection was adopted by the UN in 2026.
