Understanding how the metabolic rates of prokaryotes respond to temperature is fun-
damental to our understanding of how ecosystem functioning will be altered by climate
change, as these micro-organisms are major contributors to global carbon efflux. Ecological
metabolic theory suggests that species living at higher temperatures evolve higher growth
rates than those in cooler niches due to thermodynamic constraints. Here, using a global
prokaryotic dataset, we find that maximal growth rate at thermal optimum increases with …