Deserts & Desertification

Brazil has no true climatic desert — its entire territory receives enough rainfall to fall outside the arid Köppen "BW" classification. But large stretches of the semi-arid Northeast are degrading so severely that they now function like one, and the federal government treats desertification as a serious national threat.

Gilbués, Piauí

Brazil's most severe "desertification nucleus," nicknamed the country's own desert. Despite a sub-humid ~1,200 mm/year of rainfall, fragile sandy-clay soils have been carved by hydric erosion — laminar sheetwash progressing into deep gullies and canyon-like badlands — into a bare, cratered landscape closer to a reg-style stony/gullied wasteland than a true erg dune sea.

Irauçuba, Cabrobó & Seridó

Three more nuclei (Ceará, Pernambuco, and Rio Grande do Norte/Paraíba) sit on exposed crystalline basement rock under classic semi-arid conditions, below 800 mm of rain a year. Thin, rocky, over-grazed Caatinga soils here expose bare bedrock and regolith in a pattern closer to hamada than dune-field desert.

Notably, Brazil's one true dune "sea" — the Lençóis Maranhenses erg-like field described in the wind erosion section — is not desertification at all: it sits in one of the wettest parts of the coast (over 1,600 mm of rain a year) and is fringed by freshwater lagoons, a purely wind-built landform rather than a sign of land degradation.

Desertification itself is a real and growing problem: according to Brazil's National Semi-Arid Institute (INSA), roughly 85% of the semi-arid Northeast — home to about 28 million people — is in a state of moderate desertification, and 9% is already effectively desertified. In response, the government launched the PAB-Brasil (Plano de Ação Brasileiro de Combate à Desertificação) in December 2025: 175 initiatives aiming to restore 10 million hectares of degraded Caatinga land by 2045, paired with a payment-for-environmental-services registry that compensates indigenous peoples, traditional communities, and family farmers for conservation, alongside on-the-ground restoration efforts like the Raízes da Caatinga program.