Global human and economic losses from river floods are set to increase in coming years, even with the most optimistic climate outlook.
Scientists modelled human losses and economic damages from river floods at the global scale for three climate scenarios – of 1.5°C, 2°C and 3°C warming.
From the current yearly average of 5,700 deaths from river flooding in the world, annual loss of life could rise:
- 83% at 1.5°C global warming;
- 124% at 2°C;
- 265% at 3°C.
The high cost of floods – long and short term
Estimates of immediate economic costs and long term impacts tell a similar story.
Depending on the socio-economic scenario, with 1.5°C warming direct flood damage is set to increase by 160–240%.
The longer-term welfare losses – reduction in consumption compared to the scenario without climate impacts - could reach 0.3%.
With 2 °C warming, direct economic damage doubles and welfare losses grow to 0.4%.
Impacts are substantially higher with 3°C warming.
Long term losses could even exceed direct damages, due to the increased persistent effects on the economy.
The scientists also show how flood impacts will have an uneven regional distribution.
Countries in the Asian continent and in Sub-Saharan Africa are the most affected now, and will have rising shares of the global direct and indirect impacts at all analysed warming levels.
River flood impacts will rise considerably also in Europe, even though at a slower rate than the global average.
Human losses could increase by 45%-55% under a 1.5°C warming scenario, and up to 85% at 3°C, depending on the socio-economic scenario considered.
Economic damage in Europe shows larger increases by 90%-160% under a 1.5°C warming and up to 385% at 3°C.
Increased climate adaptation and mitigation efforts are needed to offset this increasing risk in the future.
By assessing the long term impacts across regions - taking into account both immediate costs and the strain on economic growth - scientists provide evidence to help policymakers prepare effective adaptation plans to offset increasing river flood risk.
The study, led by JRC researchers, is published in Nature Climate Change.
Under the Paris climate agreement, countries have committed to keeping global average temperature rise well below 2°C and aim to limit the increase to 1.5°C, while increasing the ability to adapt to the adverse impacts of climate change.
This study confirms the significant impact of global warming on the danger of river floods to human lives, livelihoods and economies.
Limiting global warming and adapting to inevitable impacts are both essential to managing climate risks.
Considerable increases in river flood impacts are predicted even under the most optimistic scenario of 1.5°C warming as compared to pre-industrial levels.
Therefore, policymakers should design appropriate adaptation plans to reduce potential impacts.