Understanding river temperature to better understand the effects of climate change  

University of Birmingham, UK, and Indiana University, USA researchers are calling for an increased focus on river temperatures to better understand the effects of climate change and human activity. In a comment piece in the new journal, Nature Water, the researchers argue that river temperature is a fundamental water quality measure that regulates physical, chemical and biological processes in flowing waters, which in turn affects ecosystems, human health, and industrial, domestic, and recreational uses by people.

The researchers suggest that river temperature holds important clues about climate change and other human impacts. Rising river temperatures could be a critical indicator for the effects of climate change, including early warning of algal blooms, waterborne pathogens, and effects on fish populations, which may be essential for human survival in many parts of the globe.

A comprehensive understanding of river temperatures will lead to improved understanding of temperature changes on biodiversity, ecosystem functioning, and risks. This understanding is crucial in managing, mitigating, and adapting to high temperature extremes that are damaging to aquatic organisms and ecosystem services for people.

“The knowledge we currently have is inconsistent, with large variations in scale and detail – and primarily taking place in richer countries. This severely limits our ability to sustainably manage river systems, protect ecosystems and balance the competing interests of stakeholders,” said co-lead author Professor Darren Ficklin of Indiana University.

The researchers suggest creating a complete and accessible river temperature archive to highlight information gaps and underpin models for places and times for which data is lacking. By co-producing river temperature knowledge, the researchers also hope to promote collaborative research and management efforts with local and indigenous communities, avoiding ‘top-down’ decision-making on which types of data are most valuable.

Co-lead author, Professor David Hannah, UNESCO Chair in Water Sciences at the University of Birmingham, said, “More attention has been given to other water quality indicators, such as nutrients and contaminants. However, river temperature influences many of these factors. Emerging evidence shows that river temperatures are rising in response to climate change in many regions worldwide. On top of this, human activity is altering water temperature further; but we still need to better understand this phenomenon and its implications.”

The researchers urge for a better understanding of the role played by humans on river water temperature, which will be crucial to manage, mitigate and adapt to high temperature extremes that are damaging to aquatic organisms and ecosystem services for people.