New BG Letter: Evidence for highly variable land use but a stable climate in the southwest Maya lowlands

21 November 2025

Over time, traces of humans, fire, and plants accumulate at the bottom of lakes. They reveal the history of how the lowland Maya, a society thought to have declined due to drought, transformed their environment over time. The authors show how forest was cleared, agriculture expanded, and population levels rose then declined. However, the record does not show drought even though population declines. This challenges the idea that climate was the primary cause of the societal changes.

Co-editor-in-chief's statement: The study analyzed lake sediments from the southwest Maya lowlands to track past land use and population size. The authors found that over 3,300 years, land use was highly variable, with more fire and maize agriculture earlier (3500–2000 BP) with a denser population but less burning in a later period (1600–1000 BP). Surprisingly, their hydrogen isotope data showed no strong signature of drought locally, suggesting that climate in that area remained relatively stable. Therefore, the authors argue that collapse or population decline in the southwest Maya lowlands was likely driven more by social, political, or regional factors than by local drought.

Contact: Benjamin Gwinneth (benjamin.gwinneth@umontreal.ca)