Potential effects of warmer worms and vectors on onchocerciasis transmission in West Africa

Development times of eggs, larvae and pupae of vectors of onchocerciasis (Simulium spp.) and of Onchocerca volvulus larvae within the adult females of the vectors decrease with increasing temperature. At and above 25C,the parasite could reach its infective stage in less than 7 days when vectors could transmit after only two gonotrophic cycles. After incorporating exponential functions for vector development into a novel blackfly population model, it was predicted that fly numbers in Liberia and Ghana would peak at air temperatures of 29C and 34C, about 3C and 7C above current monthly averages, respectively; parous rates of forest flies (Liberia) would peak at 298C and of savannah flies (Ghana) at 308C. Small temperature increases (less than 28C) might lead to changes in geographical distributions of different vector taxa. When the new model was linked to an existing framework for the population dynamics of onchocerciasis in humans and vectors, transmission rates and worm loads were projected to increase with temperature to at least 338C. By contrast, analyses of field data on forest flies in Liberia and savannah flies in Ghana, in relation to regional climate change predictions, suggested, on the basis of simple regressions, that 13–41% decreases in fly numbers would be expected between the present and before 2040. Further research is needed to reconcile these conflicting conclusions

2019 State of Climate Services: Agriculture and Food Security

In 2018, the Conference of the Parties serving as the meeting of the Parties to the Paris Agreement at the 24th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC) called on the World Meteorological Organization (WMO) through its Global Framework for Climate Services (GFCS) to regularly report on the state of climate services with a view to “facilitating the development and application of methodologies for assessing adaptation needs” (Decision 11/CMA.1). This inaugural 2019 State of Climate Services Report focuses on agriculture and food security. It reviews countries’ priorities on climate services for adaptation, noting that agriculture is one of the highest, and identifies priority capacity needs. It examines capacity gaps across six components of the climate services value chain including: governance, basic systems, user interface, capacity development, provision and application of climate services, and monitoring and evaluation. The report provides case studies, examples and explanations as to the role of climate information and services to support agriculture in the face of climate variability and change, assesses gaps and makes recommendations. This analysis helps highlight both challenges and opportunities for climate service efforts aimed at promoting climate resilient development and adaptation action