country areas are not areas

[edzer]

In notebook 02, the areas you compute with countries.geometry.area are not areas; they're computed as if geographic coordinates are Cartesian - their unit is squared degrees, which is meaningless (because dependent on latitude).

[edzer]

Ah, I now see the warning: "/tmp/ipykernel_603399/3077649407.py:1: UserWarning: Geometry is in a geographic CRS. Results from 'area' are likely incorrect. Use 'GeoSeries.to_crs()' to re-project geometries to a projected CRS before this operation." Well, you can leave out the likely, but better return an error.