Mercedes and her collaborators’ new paper showing that a decline in malaria cases in the highlands of Ethiopia was driven by a transient slowdown in global warming and associated changes in climate variability was recently published in Nature Communications! Their article has been covered in a press release from the Barcelona Institute for Global Health.
Quantifying the extent to which changes in malaria transmission are driven by changes in climate has important implications for control strategies. Global warming is expected to promote malaria transmission in highlands because temperature decreases with elevation, limiting both the abundance of mosquitoes and the development of the parasite within these vectors. In her previous work, Mercedes showed that warmer temperatures exacerbated unstable malaria in densely populated highlands in East Africa from the 1980s to the 1990s. Since the year 2000, however, malaria transmission in the highlands of Ethiopia decreased. While this observed decline has been used as a counterargument to the importance of climate change for malaria transmission, the turnaround in malaria incidence could reflect a strong coupling to temperatures rather than a consequence of control interventions per se. Using statistical analyses and a process-based transmission model, Mercedes and her colleagues Xavier Rodó, Pamela P. Martinez, and Amir Siraj showed that this decline was driven by a transient slowdown in global warming and associated changes in climate variability, especially ENSO. Decadal changes in temperature and concurrent climate variability facilitated rather than opposed the effect of interventions.
The full published study can be found on the Nature Communications website.