Global meta-analysis of metabolic responses to climate change in aquatic and terrestrial invertebrates

Climate change is transforming living systems worldwide, with its impact primarily mediated through organisms' metabolic rates. Understanding how metabolic rate responds to climate change and identifying which ecosystems and geographic areas will be severely affected remain urgent priorities. Here, we assemble and meta-analyse a dataset to establish the current state of knowledge on thermal sensitivity of metabolic rate (i.e. the degree of metabolic response to temperature) and its plasticity, and how these vary geographically and across ecosystems in invertebrates-Earth's most diverse yet understudied organisms. We demonstrate that invertebrates from aquatic ecosystems exhibit a lower metabolic response to temperature than those from terrestrial ones, with this response increasing with latitude, though more sharply in terrestrial ecosystems. Organisms inhabiting warm and stable climates show greater capacity for metabolic plasticity to counteract temperature effects. Conversely, cold and more variable climates shape heightened thermal sensitivity, particularly in terrestrial ecosystems. We forecast substantial increases in metabolic rates even under a modest climate change scenario (CMIP5-RCP2.6), with increases of up to 26.6% in aquatic and 43.9% in terrestrial invertebrates. These pronounced warming impacts on terrestrial species and those at higher latitudes suggest that they are among the most at risk, more so than previously thought.