Scientists at the UK Centre for Ecology & Hydrology are supporting preparations for possible significant flooding or drought in future decades as a result of climate change.
They are modelling the impacts on river flows from a range of ‘high-impact low-likelihood’ scenarios for the UK. These go beyond the range of conventional climate projections, which already indicate worsening floods and droughts in future.
The worst-case climate projections could involve the collapse of Atlantic Meridional Overturning Circulation (AMOC), a system of currents that circulate water within the ocean. This would cause cooling of the northern hemisphere, bringing more snow and therefore water on melting, resulting in increased river flows .
“A significant increase in snowfall could cause substantial changes in average and peak river flows in the north of Britain, resulting in more frequent and severe flooding in the region,” said Dr Alison Kay, senior mathematical modeller at UKCEH who led the new research.
One of the other scenarios involved more severe warming of the Arctic. This could lead to reduced river flows across the UK, potentially further worsening droughts in the future, according to the UKCEH study.
Dr Kay said: “Studies such as ours add impetus to efforts to mitigate climate change and its impacts. They strengthen the evidence for reducing greenhouse gases and help adaptation planning, particularly for critical infrastructure.”
Paper information
UKCEH’s hydrological modelling, funded by the Hydro-JULES programme, has been published as an open access paper in the journal Environmental Research Communications ('Hydrological impacts from transient high-impact low-likelihood climate scenarios for Great Britain', DOI: 10.1088/2515-7620/ae66a8).
It was based on high-impact low-likelihood (HILL) climate scenarios produced by the University of Reading and the University of Southampton and funded under the UK Climate Resilience Programme.