2,500 Years of Hydroclimate Variability in New Mexico, USA

We provide a 2,508-year reconstruction (492 BCE–2015 CE) of hydroclimate variability for west-central New Mexico using the long-lived conifer Rocky Mountain juniper (Juniperus scopulorum Sarg.). The reconstruction model explains 53% of the instrumental soil moisture variance and all validation statistics indicate a skillful record. More hydroclimate flips (extreme wet-dry, vice versa) occur during the 20th–21st century than any other century in the past 2,500 years. Yet, drought and pluvial events captured during the instrumental period (since ca. 1900) do not represent the full range and variability of historical conditions. Since ca. 500 BCE, over 50 drought events have surpassed the severity of recent 21st century conditions, including the first documentation of a prolonged and severe drought during the second to third century BCE (Pre-Ancestral Puebloan). Continued extreme hydroclimate variability (e.g., flips) in the 21st century could create infrastructure challenges for regional water planning authorities in this arid region.