Scientists from Cardiff University have found that Britain’s urban rivers are the cleanest they’ve been in over two decades.

The 21-year study of over 2,300 rivers measured the presence of clean-river invertebrates – a yardstick for river health – which during the days of heavy industry and poor sewage treatment had declined considerably, but now appear to be making a comeback.

Although climate change has warmed British rivers by around 1-2 degrees over recent decades, the findings suggest that improved pollution control has managed to offset its damaging effects on river ecosystems. This indicates that society can prevent some undesirable climate change effects on the environment by improving habitat quality.