Drought caused 'historic' hydropower drop: Study

LONDON

Dry conditions, particularly in China, caused a "historic" global drop in hydropower generation in the first half of 2023, a new analysis shows, highlighting the effects of climate change.

The research by renewable energy think tank Ember argues the drop is a "warning shot that hydro output could negatively affect the speed of the electricity transition."

The group said global hydropower generation fell 8.5 percent in the year to June, more than any full-year decline over the last two decades.

Three-quarters of that decline was the result of falls in China, which baked through record temperatures earlier this year.

The fall in hydropower output meant global carbon emissions rose very slightly in the first half of 2023, despite a 12-percent increase in solar and wind power worldwide.

Lower growth in electricity demand helped keep the rise in emissions smaller than it might otherwise have been, Ember said in the report.

China, however, saw its emissions rise nearly eight percent as it compensated for the loss of hydropower.

But while the extreme heat and drought conditions that caused this year's decline may have been driven by climate change, the think tank warned it remains hard to calculate future effects.

The consequences of "climate change on hydro potential are geographically varied", the group noted.

"Changes in rainfall patterns and intensity as well as increased evaporation will affect hydro output both positively and negatively depending on the region."

Some parts of central Africa, India, central Asia and northern high latitudes could see their potential to generate hydropower increase.

But in southern Europe, the southern United States and elsewhere, it is likely to weaken.