What influence does anthropogenic climate change have on droughts and floods, and how does local human activity change the vulnerability of regions? The division of climate risk into individual factors is crucial to develop the right adaptation measures. This project is based in South Africa, but results are applicable to a wider range of climate change loss and damage situations across the world.
Our work
Sufficient water supply is vital for all aspects of human life, particularly agriculture, industry and thus food supply. Both the absence of rain – leading to drought – and intensive heavy rainfall – leading to flooding – cause major problems in the supply of clean water.
Combined with climate change, variation in water management and consumption change how these events play out, particularly in highly vulnerable parts of the world. The HIASA project focused on identifying and understanding changes in extreme hydrological events in Southern Africa, in particular catchment areas for large cities.
Two factors were examined to determine the vulnerability of different areas:
- Exposure: What is the impact of human climate change on droughts and floods?
- Sensitivity: How do local human activities change vulnerability to climate events?
These questions helped to attribute the changing risk of significant droughts and floods. We also estimated economic damage, the benefits of adaptation, and any residual economic damage that remains after adaptation.
Our research also enabled us to identify the most effective adaptation measures to decrease vulnerability, set the right priorities, and prevent future loss and damage. Above all, the evaluation of the economic and social benefits of adaptation measures is crucial for the most efficient use of resources.
This project aimed to assess the effectiveness of different kinds of responses, to reduce the vulnerability of African countries to climate change in the future and to generate effective adaptation programmes.
Models & results
We used attribution methods from World Weather Attribution and adapted them to the region.
The project investigated the drought in West South Africa from 2015 to 2017, which caused major problems with water shortages in Cape Town in 2018 (Day Zero), and identified a need for adaptation for the city and the region.
- Otto, F.E.L., Wolski, P., Lehner, F., Tebaldi, C., Jan van Oldenborgh, G., Higesteeger, S., Singh, R., Holden, P., Fučkar, N.S., Odoulami, R. and New, M. 2018. Anthropogenic influence on the drivers of the Western Cape drought 2015 – 2017. Environmental Research Letters, 13(12): 124010. doi: 10.1111/j.1740-9713.2018.01127.x
- Wolski, P. 2018. How severe is Cape Town‘s "Day Zero" drought? Significance, 15(2): 24–27. doi: 10.1111/j.1740-9713.2018.01127.x
- Conway, D., Nicholls, R.J., Brown, S. et al. 2019. The need for bottom-up assessments of climate risks and adaptation in climate-sensitive regions. Nature Climate Change 9, 503–511. doi: 10.1038/s41558-019-0502-0
- Mugari, E., Masundire, H., Bolaane, M. and New, M. 2019. Perceptions of ecosystem services provision performance in the face of climate change among communities in Bobirwa sub-district, Botswana. International Journal of Climate Change Strategies and Management, 11(2). doi: 10.1108/IJCCSM-09-2017-0178
- Nkemelang, T., New, M. and Zaroug, M. 2018. Temperature and precipitation extremes under current, 1.5 °c and 2.0 °c global warming above pre-industrial levels over Botswana, and implications for climate change vulnerability. Environmental Research Letters, 13(6): 065016. doi: 10.1088/1748-9326/aac2f8
- Cole, M.J., Bailey, R.M., Cullis, J.D.S. and New, M.G. 2018. Water for sustainable development in the Berg Water Management Area, South Africa. South African Journal of Science 114(3-4). doi: 10.17159/sajs.2018/20170134