Current hydroclimatic spaces will be breached in half of the world’s humid high-elevation tropical ecosystems

Humid high-elevation tropical ecosystems (HETEs), known as páramos, jalca, or moorlands, are essential for biodiversity conservation and water supply. Yet, a key question remains of how future climate change will affect their hydroclimatic spaces: the multidimensional hydroclimatic conditions in which they currently thrive. We use CMIP6-downscaled climate data to assess the potential breaching of these hydroclimatic spaces concerning the long-term means, extremes, and seasonality of temperature and precipitation. Our results show that HETEs in Northern South America will experience the largest increase in temperature and decrease in precipitation, leading to the breaching of their current hydroclimatic space by up to 100%. In the Afrotropics and Australasia, HETEs will experience a breaching of their hydroclimatic spaces related to long-term means and extremes. Our findings provide relevant information on the vulnerability of HETEs to climate change, offering insights to inform the integration of adaptation measures into policy development and management strategies for conserving these key ecosystems and their services.