EGU21-15485
https://doi.org/10.5194/egusphere-egu21-15485
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Unprecedented climate extremes in Sub-Saharan Africa and implications for maize production

Catherine Bradshaw1, Edward Pope1, Gillian Kay1, Jemma Davie1, Andrew Cottrell1, James Bacon1, Stewart Jennings2, Andrew Challinor2, Sarah Chapman2, Cathryn Birch2, and Susannah Sallu2
Catherine Bradshaw et al.
  • 1Met Office, Applied Science, Exeter, United Kingdom of Great Britain – England, Scotland, Wales (catherine.bradshaw@metoffice.gov.uk)
  • 2School of Earth and Environment, University of Leeds, Leeds, UK

Sub-Saharan Africa is one of the most food-insecure regions in the world, and is particularly vulnerable to the impacts of extreme climate events and climate change.  To gain a better understanding of the present-day likelihood of extreme seasonal temperature and rainfall events, and their joint occurrence, we apply the UNprecedented Simulated Extremes using ENsembles (UNSEEN) approach  to a large ensemble of high-resolution initialised climate simulations in three countries of Sub-Saharan Africa: Tanzania, Zambia and South Africa. We assess the annual likelihood of unprecedented seasonal temperature and precipitation extremes during the maize growing season (October-April), as key variables for maize productivity , and investigate the large-scale dynamics of the climate system that govern their occurrence. We estimate that there is a 3-4% chance per year of exceeding the present-day seasonal temperature records in the maize growing regions of these countries, and a 1-3.5% chance per year of exceeding the present-day seasonal precipitation records.  Conversely, whilst we find a 2% and 5% chance per year of subceeding the present-day seasonal precipitation records in Zambia and Tanzania respectively, we find a very low chance (0-1% per year) of subceeding the present-day seasonal precipitation records in South Africa.  We also use the large ensemble to investigate the large-scale dynamics of the climate extremes, finding that high temperature extremes tend to be associated with El Niño and positive IOD/SIOD events and low temperature extremes with La Niña and negative IOD/SIOD events. The drivers of precipitation extremes, however, differ between the countries. In South Africa, high (low) precipitation extremes are associated with La Niña (El Niño) events but otherwise the influence on extremes of ENSO, and even more so the IOD/SIOD, is weak or not seen in the ensemble, which invites further investigation. To explore implications for growing maize in these regions, we convert our unprecedented seasonal temperature estimates to daily maximum temperatures and our seasonal precipitation estimates to monthly precipitation indices and compare to climatic thresholds for maize. Combined with projected changes to crop suitability in much of sub-Saharan Africa, our analysis suggests the need for significant adaptation strategies that build food system resilience in the near and longer term.

How to cite: Bradshaw, C., Pope, E., Kay, G., Davie, J., Cottrell, A., Bacon, J., Jennings, S., Challinor, A., Chapman, S., Birch, C., and Sallu, S.: Unprecedented climate extremes in Sub-Saharan Africa and implications for maize production, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15485, https://doi.org/10.5194/egusphere-egu21-15485, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.