Desert, Forest, Ice: the World's Land in 1900 and Now, from HYDE 3.3

I compare the use of the world's land in 1900 and 2023 using the gridded estimates of the History Database of the Global Environment, version 3.3 (HYDE), at 5 arc-minutes, with HYDE's anthromes and its map of the potential forest zone, and check the present against MODIS satellite land cover for 2019. In HYDE's baseline estimate, cropland grew from 9.0 to 16.3 million km² and grazing land from 15.7 to 32.0 million km², so that farmland rose from 19.1% to 37.3% of the ice-free land outside Antarctica. The largest gains were in sub-Saharan Africa and South America, and by country in China, Brazil and Australia; Europe is the only region with less farmland than in 1900. Within the potential forest zone the farmed share rose from 16.4% to 27.3%, a net 6.4 million km², the result of 7.6 million km² going into farming, mostly in the tropics, and 1.2 million km² going out of it, 87% of that in Europe, Russia and the United States. The anthromes show that wildlands barely changed in extent (25.2% to 24.0% of ice-free land) while seminatural lands shrank from 40.1% to 24.1%. I discuss what a modelled reconstruction of 1900 can and cannot show. Interactive version: https://maps.tristanhotham.com/land-cover-1900/. Data and code: https://github.com/Tristan-Hotham/land-cover-1900.