Robust increase in observed heat storage by the global subsurface

Changes in heat storage within the different components of the climate system alter physical and biogeochemical phenomena relevant for human societies and ecosystems. Among such processes, permafrost thawing, soil carbon storage, and surface energy exchanges depend on the persistent heat gain by the continental subsurface. Nevertheless, there are not enough data to estimate ground heat storage at the global scale after the year 2000. We solve this problem by expanding the database of geothermal data with remote sensing observations from satellite platforms. Estimates from satellite data show a heat gain between 16.4 ± 3.4 and 21.78 ± 0.62 zettajoules during the past six decades. The global ground heat storage presents a positive acceleration between 0.16 ± 0.15 and 0.624 ± 0.032 zettajoules per square decade, similarly to the rest of components of the Earth heat inventory. The planned satellite missions ensure the monitoring of the land component of the Earth heat inventory in the future.