Climate change increased rainfall associated with tropical cyclones hitting highly vulnerable communities in Madagascar, Mozambique & Malawi

The study concludes that greenhouse gas and aerosol emissions contributed to the increased intensity and probability of heavy rainfall during the 2022 tropical storm events in Madagascar, Mozambique, and Malawi. While Tropical Storm Ana was a rare 1-in-50-year event for Mozambique and Malawi, Cyclone Batsirai was a more common 1-in-2-year event for Madagascar. The humanitarian impact was severely amplified by compound factors, including preceding floods, existing droughts in southern Madagascar, and high socio-economic vulnerability. Despite accurate forecasting by regional meteorological centers, infrastructure damage and a lack of trust in warnings hindered effective responses.

• Anthropogenic climate change, specifically greenhouse gas and aerosol emissions, is partially responsible for the observed increases in the likelihood and intensity of heavy rainfall associated with Tropical Storm Ana and Cyclone Batsirai.
• The meteorological extremity of the two events differed significantly by region: Tropical Storm Ana had a return period of approximately 1 in 50 years for Malawi and Mozambique, whereas Cyclone Batsirai was a 1 in 2 year event for Madagascar.
• The humanitarian disasters were exacerbated by compound events, where communities were hit by consecutive storms without time to recover, often following preceding floods or existing droughts.
• While meteorological agencies provided accurate forecasts and tracking for both Ana and Batsirai, the effectiveness of these warnings was compromised by damaged communication grids and a lack of trust in the information.
• The region's high vulnerability is linked to socio-economic factors, including a heavy reliance on agriculture in floodplains and the lingering economic impacts of the Covid-19 pandemic.
• Quantitative attribution is challenging due to sparse observational data and discrepancies between gridded datasets, but qualitative trends show an increase in the intensity of heavy rainfall associated with tropical cyclones.

APA

Otto, F. E. L., Zachariah, M., Wolski, P., Pinto, I., Barimalala, R., Nhamtumbo, B., Bonnet, R., Vautard, R., Philip, S., Kew, S., Luu, L. N., Heinrich, D., Vahlberg, M., Singh, R., Arrighi, J., Thalheimer, L., van Aalst, M., Li, S., Sun, J., ... Harrington, L. J. (n.d.). Climate change increased rainfall associated with tropical cyclones hitting highly vulnerable communities in Madagascar, Mozambique & Malawi. World Weather Attribution. https://www.worldweatherattribution.org/wp-content/uploads/WWA-MMM-TS-scientific-report.pdf

Chicago

Otto, Friederike E. L., Mariam Zachariah, Piotr Wolski, Izidine Pinto, Rondrotiana Barimalala, Bernardino Nhamtumbo, Remy Bonnet, et al. Climate change increased rainfall associated with tropical cyclones hitting highly vulnerable communities in Madagascar, Mozambique & Malawi. World Weather Attribution, n.d. https://www.worldweatherattribution.org/wp-content/uploads/WWA-MMM-TS-scientific-report.pdf.

Wikipedia

{{cite report |last1=Otto |first1=Friederike E. L. |last2=Zachariah |first2=Mariam |last3=Wolski |first3=Piotr |last4=Pinto |first4=Izidine |last5=Barimalala |first5=Rondrotiana |last6=Nhamtumbo |first6=Bernardino |last7=Bonnet |first7=Remy |last8=Vautard |first8=Robert |last9=Philip |first9=Sjoukje |display-authors=etal |title=Climate change increased rainfall associated with tropical cyclones hitting highly vulnerable communities in Madagascar, Mozambique & Malawi |publisher=World Weather Attribution |url=https://www.worldweatherattribution.org/wp-content/uploads/WWA-MMM-TS-scientific-report.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{ottondclimate, author = {Otto, Friederike E. L. and Zachariah, Mariam and Wolski, Piotr and Pinto, Izidine and Barimalala, Rondrotiana and Nhamtumbo, Bernardino and Bonnet, Remy and Vautard, Robert and Philip, Sjoukje and Kew, Sarah and Luu, Linh N. and Heinrich, Dorothy and Vahlberg, Maja and Singh, Roop and Arrighi, Julie and Thalheimer, Lisa and van Aalst, Maarten and Li, Sihan and Sun, Jingru and Vecchi, Gabriel and Harrington, Luke J.}, title = {{Climate change increased rainfall associated with tropical cyclones hitting highly vulnerable communities in Madagascar, Mozambique \& Malawi}}, institution = {World Weather Attribution}, url = {https://www.worldweatherattribution.org/wp-content/uploads/WWA-MMM-TS-scientific-report.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }