Summary
The recent mass mortality event of more than 330 African elephants in Botswana has been attributed to biotoxins produced by cyanobacteria; however, scientific evidence for this is lacking. Here, by synthesizing multiple sources of data, we show that, during the past decades, the widespread hypertrophic waters in Southern Africa have entailed an extremely high risk and frequent exposure of cyanotoxins to the wildlife within this area, which functions as a hotspot of mammal species richness. The hot and dry climatic extremes have most likely acted as the primary trigger of the recent and perhaps also of prehistoric mass mortality events. As such climate extremes are projected to become more frequent in Southern Africa in the near future, there is a risk that similar tragedies may take place, rendering African megafauna species, especially those that are already endangered, in risk of extinction. Moreover, cyanotoxin poisoning amplified by climate change may have unexpected cascading effects on human societies. Seen within this perspective, the tragic mass death of the world's largest terrestrial mammal species serves as an alarming early warning signal of future environmental catastrophes in Southern Africa. We suggest that systematic, quantitative cyanotoxin risk assessments are made and precautionary actions to mitigate the risks are taken without hesitation to ensure the health and sustainability of the megafauna and human societies within the region.
With anthropogenic global warming, heat‐related extreme events are projected to increase in severity and frequency. Already vulnerable regions like Africa will be hard‐hit. Therefore, such regions could benefit from low global warming levels. Using the Community Earth System Model low warming simulations, we investigate changes in temperature extremes across Africa as a function of global mean temperature in the context of the implications of the Paris Agreement's targets. A significant warming across Africa is projected at the 1.5 °C warming world and is amplified at the 2 °C world, exceeding the mean global warming rate. Specifically, North Africa and East Africa regions are projected to have the highest and lowest temperature changes of 0.63 °C (0.60–0.67 °C) and 0.50 °C (0.47–0.54 °C), respectively, between the 1.5 and 2 °C warmer worlds. Consequently, hot events are also estimated to increase with global warming. We showed that limiting warming to 1.5 °C instead of 2 °C may lead to 29% (27–31%) to 35% (33–37%) reduction in severity of hot events and to 31% (30–33%) to 42% (39–48%) reduction in the frequency of the threshold‐based high‐temperature events across Africa. The highest reductions are projected over North Africa. Furthermore, restricting warming to 0.5 °C lower than 2 °C might also result in 28% (34–40%) to 37% (25–34%) reduction in severity of once‐in‐10/20‐year heat events across Africa with North Africa having the highest benefits than tropical regions. Thus, restricting warming to low levels may indeed translate to substantial benefits of reduced intensity and frequency of extreme heat events across Africa.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.