Global drivers of future river flood risk

Understanding global future river flood risk is a prerequisite for the quantification of climate change impacts and planning effective adaptation strategies. Existing global flood risk projections fail to integrate the combined dynamics of expected socio-economic development and climate change.

New global river flood risk projections

We present the first global future river flood risk projections that separate the impacts of climate change and socio-economic development. The projections are based on an ensemble of climate model outputs, socio-economic scenarios, and a state-of-the-art hydrologic river flood model combined with socio-economic impact models.

Flood risks increase factor 20, without action

Globally, absolute damage may increase by up to a factor of 20 by the end of the century without action. Countries in Southeast Asia face a severe increase in flood risk. Although climate change contributes significantly to the increase in risk in Southeast Asia, we show that it is dwarfed by the effect of socio-economic growth, even after normalization for gross domestic product (GDP) growth.

Climate change relevant driver

African countries face a strong increase in risk mainly due to socio-economic change. However, when normalized to GDP, climate change becomes by far the strongest driver. Both high- and low-income countries may benefit greatly from investing in adaptation measures, for which our analysis provides a basis.

The global flood risk model GLOFRIS has been used in various recent assessments, amongst others:

>PBL 2014. Towards a world of cities in 2050. An outlook on water-related challenges

>GWP/OECD 2015. Securing Water, Sustaining Growth

>World Bank 2015. Shock waves. Managing the impacts of climate change on poverty

Authors

Hessel C. Winsemius, Jeroen C. J. H. Aerts, Ludovicus P. H. van Beek, Marc F. P. Bierkens, Arno Bouwman, Brenden Jongman, Jaap C. J. Kwadijk, Willem Ligtvoet, Paul L. Lucas, Detlef P. van Vuuren and Philip J. Ward

Specifications

Publication title
Global drivers of future river flood risk
Publication date
21 December 2015
Publication type
Publication
Magazine
Nature Climate Change 2015
Product number
2350