Nature Reviews Biodiversity

Jin, Y., Behrens, P., Zhong, X. et al. Water temperature regulations could help to balance biodiversity and energy security. Nat. Rev. Biodivers. (2025). https://doi.org/10.1038/s44358-025-00069-2

Thermoelectric power plants discharge heat into water, which can harm aquatic species. Some regions regulate water discharge temperatures, but these regulations can cause outages, which makes compliance under global warming difficult to ensure. In this Comment, we argue that locally specific, optimized policies can help to balance biodiversity protection and energy demand.

Thermal power stations require large amounts of water for cooling; after moving through cooling systems, warm water is discharged into natural waterways, which increases water temperature and poses a threat to freshwater life1. Globally, thermal power plants release 3,711 terawatt hours of energy per year into natural water bodies, which is equivalent to around 13.7% of the global electricity supply. Policy makers face an important regulatory choice: requiring that power plants release water at lower temperatures could benefit biodiversity, but could also cause power producers to curtail power production.