Attribution of severe low rainfall in southern Madagascar, 2019-21

The study investigates a severe drought in southern Madagascar (the Grand Sud region) between July 2019 and June 2021, which contributed to a major food security crisis. Analysis of observational data and climate models indicates that the event was a 1-in-135 year dry event, but its likelihood was not significantly increased by anthropogenic climate change. The findings suggest that natural variability remains the dominant driver of such droughts in this region, aligning with IPCC projections that perceptible changes in drought may only emerge if global mean temperatures exceed 2°C above pre-industrial levels. The report also highlights that the humanitarian impact was severely compounded by extreme poverty, poor infrastructure, and the COVID-19 pandemic.

• The rainfall deficit in the Grand Sud region from July 2019 to June 2021 was an exceptional event, with the rainy seasons of 2019/20 and 2020/21 receiving only 60% of normal rainfall.
• The 24-month period of low rainfall from July 2019 to June 2021 is estimated as a 1-in-135 year dry event, surpassed in severity only by the drought of 1990-92.
• Human-caused climate change did not significantly increase the occurrence of the poor rains observed between July 2019 and June 2021, as trends are currently overwhelmed by natural variability.
• Large-scale teleconnections, including El Niño and La Niña, did not significantly alter the likelihood of these rainfall deficits; for example, the 2020/21 season was exceptionally dry despite a moderate La Niña event.
• The synthesis of observations and models shows a non-significant probability ratio of 1.36 and a non-significant change in total rainfall intensity of -2.1% when comparing the current climate to a pre-industrial climate 1.2°C cooler.
• The food security crisis was exacerbated by extreme socio-economic vulnerability, with 91% of the population in the Grand Sud region living below the poverty line.
• The COVID-19 pandemic acted as a risk multiplier by restricting movement and reducing income-earning opportunities for daily wage laborers who typically migrate for work during poor yield years.
• Other compounding factors contributing to the food crisis included pest infestations, specifically migratory locusts and Fall Armyworm, as well as poor water and road infrastructure.
• The findings are consistent with the IPCC's Sixth Assessment Report, which suggests that perceptible changes in drought in this region may only emerge if global mean temperatures exceed 2°C above pre-industrial levels.

APA

Harrington, L. J., Wolski, P., Pinto, I., Ramarosandratana, A. M., Barimalala, R., Vautard, R., Philip, S., Kew, S., Singh, R., Heinrich, D., Arrighi, J., Raju, E., Thalheimer, L., Razanakoto, T., van Aalst, M., Li, S., Bonnet, R., Yang, W., Otto, F. E. L., & van Oldenborgh, G. J. (n.d.). Attribution of severe low rainfall in southern Madagascar, 2019-21. World Weather Attribution. https://www.worldweatherattribution.org/wp-content/uploads/ScientificReport_Madagascar.pdf

Chicago

Harrington, Luke J., Piotr Wolski, Izidine Pinto, Anzela Mamiarisoa Ramarosandratana, Rondrotiana Barimalala, Robert Vautard, Sjoukje Philip, et al. Attribution of severe low rainfall in southern Madagascar, 2019-21. World Weather Attribution, n.d. https://www.worldweatherattribution.org/wp-content/uploads/ScientificReport_Madagascar.pdf.

Wikipedia

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BibTeX

@techreport{harringtonndattribution, author = {Harrington, Luke J. and Wolski, Piotr and Pinto, Izidine and Ramarosandratana, Anzela Mamiarisoa and Barimalala, Rondrotiana and Vautard, Robert and Philip, Sjoukje and Kew, Sarah and Singh, Roop and Heinrich, Dorothy and Arrighi, Julie and Raju, Emmanuel and Thalheimer, Lisa and Razanakoto, Thierry and van Aalst, Maarten and Li, Sihan and Bonnet, Remy and Yang, Wenchang and Otto, Friederike E. L. and van Oldenborgh, Geert Jan}, title = {{Attribution of severe low rainfall in southern Madagascar, 2019-21}}, institution = {World Weather Attribution}, url = {https://www.worldweatherattribution.org/wp-content/uploads/ScientificReport_Madagascar.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }