Climate variations, urban solid waste management and possible implications for Anopheles mosquito breeding in selected cities of coastal Ghana

Climate-induced environmental changes are known to support prevalence of disease vectors and pathogens. Temperature, rainfall, humidity and other environmental variables are considered potential drivers of population dynamics of many vectors and pathogens of health importance, especially in the tropics. This study was conducted to understand the variability and trends in atmospheric temperature and rainfall, as well as how these factors may affect the breeding of Anopheles mosquitoes in the urban areas in the future. Accra and Sekondi-Takoradi Metropolitan Areas (AMA and STMA) of coastal Ghana were the selected study sites. Anopheles larvae were sampled from pre-identified breeding sites in the two cities. Atmospheric temperature and rainfall as measured by synoptic weather stations were collected for the two cities. Again, thirty years climate data on daily minimum and maximum temperature and rainfall for both cities from Ghana Meteorological Agency (Gmet) were employed in the study. Using a statistical downscaling approach, the average of the ENSEMBLE GCM outputs AR4-BCM2 and AR4-CNCM3 scenario A1B were downscaled to match with rainfall and temperature observations of AMA and STMA. Results showed that improper solid waste management in the cities promote the breeding of Anopheles mosquitoes. Climate data analysis showed that past rainfall in the cities were below average; in the future, however, up to year 2050, the cities may experience high rainfalls and temperatures above the average. Notably, significant increases may be observed in the total monthly rainfalls as well as a slight shift of rainfall pattern in the minor season. This implies that Anopheles mosquito breeding may no longer be seasonal in the cities but perennial and malaria transmission may also follow the same trend. Poor urban dwellers who find it difficult to adopt preventative measures will be prone to persistent malaria transmission. This will increase malaria transmission among vulnerable populations in urban areas. This study recommends that city authorities must intentionally work at lowering the surface temperatures in the cities through the growing of trees and also to regularly desilt drains in order to reduce the breeding of Anopheles mosquitoes

Future flooding of the Volta Delta caused by sea level rise and land subsidence

The Volta Delta (Ghana, West Africa) is increasingly impacted by Sea Level Rise (SLR). SLR renders the Volta Delta mostly vulnerable to flooding, salinization of water resources and agricultural fields, and permanent loss of lands. This would potentially threaten its population, infrastructure and economy, and could be worsened by land subsidence (LS). Relative Sea Level Rise (RSLR) in this study is the rate of LS with respect to SLR. It is thus very important to precisely quantify LS rates together with SLR and plan and assess countermeasures. This study presents and discusses recent LS rates in the Volta Delta derived from satellite-based SAR-Interferometry and their impact on relative SLR. Sentinel-1 scenes acquired between 2015 and 2021 were used to quantify recent LS in the study area. The Persistent Scatter Interferometry (PS-InSAR) technique was applied, which allowed for estimating displacement rates of coherent backscatter targets with mm/yr precision. Separate analyses of time series for the Keta lagoon and Songor lagoon areas of the delta give insight into the vertical land movements, with irregularly distributed average rates of up to 4 mm/yr. LS in the Volta Delta is due to various causes, most prominently natural compaction of young deltaic sediments, but also aquifer over-exploitation and salt mining, and probably increasingly less compensated by a drop in sediment supply due to damming. Furthermore, projection of future elevation projections by RSLR was assessed by combining the observed LS rates with three IPCC representative concentration pathways (RCP) scenarios. The RSLR impact assessments computed revealed that by 2100, more than 20% of the Volta Delta districts could potentially be below MSL for all the addressed RCP scenarios, including the fragile but key sand barriers surrounded by water bodies. The study is, however, a preliminary investigation and recommends further local ground-based LS investigations to calibrate PS-InSAR outcome, thus improving our understanding of the areas driving critical present and future changes in the Volta Delta

WTO must ban harmful fisheries subsidies

Sustainably managed wild fisheries support food and nutritional security, livelihoods, and cultures (1). Harmful fisheries subsidies—government payments that incentivize overcapacity and lead to overfishing—undermine these benefits yet are increasing globally (2). World Trade Organization (WTO) members have a unique opportunity at their ministerial meeting in November to reach an agreement that eliminates harmful subsidies (3). We—a group of scientists spanning 46 countries and 6 continents—urge the WTO to make this commitment..