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Calls for humanity to act on environmental changes are becoming increasingly critical. The growing polycrisis including the impact of ongoing conflicts in contested geopolitical spaces and the struggles for ways to sustain a livelihood in areas of precarity and poverty, are just some of the intersecting challenges which have given rise to a Code Red alarm by the United Nations surrounding issues related to climate change. Rich narratives and stories of climate actions from Africa offer examples of potential paths. This paper explores how such narratives inform local development and climate action. A key message is that stories and narratives, created by various peoples, disciplines, and systems of knowledge, can all be powerful genres and sources for agentic change that can inspire and embolden development practice and action. [ABSTRACT FROM AUTHOR]

Relying on complex interdependence as a theoretical approach, this paper investigates the hypothetical damage that the U.S. withdrawal from the Paris Agreement could represent for Africa in terms of climate finance. In June 2017, President Donald Trump publicly declared the U.S. intention to withdraw from further participating in the multilateral Paris Agreement. To keen followers and analysts of the U.S. climate policy beyond its borders, such unilateral action was never a surprise. Rather, it is nostalgic of the experience of the Kyoto Protocol, particularly how more or less similar move unduly prolonged the global climate negotiations up till late 2015 when the Paris Agreement came about. Although the Paris Agreement is remarkable as it represents the first states-wide climate deal, it however left a number of issues unresolved. Notable among which is climate finance which has remained the most contentious and of critical concern to developing countries, particularly in Africa. Pitted against the fact that Africa contributes less to climate change and, ironically, the hardest-hit by the phenomenon, the U.S. withdrawal from the Paris Agreement aggravates concerns around climate finance and, indeed, portends additional burdens for a continent that is still struggling to cope with the untoward fallout of climate change. [ABSTRACT FROM AUTHOR]

This paper provides an in-depth analysis of a significant global challenge the international organizations are faced within the 21st century - climate change. Climate change has detrimental effects on international security and stability. In the past decades, humanity has faced emerging natural occurrences such as the increase in the World Ocean level, higher frequency of monsoon rainfalls, impaired conditions of the ecosystems in the rain forests. The massive population increase in Africa and South Asia also points to the fact that natural resources are not infinite, and their spare use becomes a priority of worldwide importance. Managing climate change is a global problem, the solution of which mandates the unified efforts of the entire international community. And this is where climate diplomacy comes at play. The efforts of climate diplomacy need to be focused on two primary directions. The first priority is limiting global warming under 2°C compared to the pre-industrial levels and taking actions to reduce the harmful emissions of greenhouse gases. The second priority is about taking adequate measures to handle climate change consequences, amongst which the so-called climate migration. [ABSTRACT FROM AUTHOR]

Climate change continues to unleash wider negative ramifications on humans, including grain production with attendant economic consequences. This paper explored the relationship between climateinduced temperature and grain production in Southern African countries. It contributes to the literature by charting the financial implication framework. Maize production was used as a proxy for grain production and archival data on maize production were collected from a sample of five Southern African countries, where high temperature and drought has inflicted havoc on grain farming within the recent years. Hence, data on the five countries were collected over six years 2011 - 2016. Applying the panel data approach and the fixed effect OLS regression, results showed a high correlation between high temperature and low maize productivity in Southern African countries. Further analysis showed that high temperature and drought has led to high cost of production on farmers, increasing price of grain and overall increase in consumer expenditure on maize, which is a staple crop in Southern Africa. The paper prepared a framework of financial implication, which touches on how the poor consumers might be affected by climate change-induced temperature increases. The paper recommends further study, which should expand on the sample size to conduct future research on this relationship. It also provides an agenda for further research on the effect of climate change induced-temperature on food poverty gap in Southern Africa. This recommendation is significant since eradication of food poverty is a vital feature of the 2030 Sustainable Development agenda. [ABSTRACT FROM AUTHOR]

Adaptation is a key component of climate policy, yet we have limited and fragmented understanding of if and how adaptation is currently taking place. In this paper, we document and characterize the current status of adaptation in 47 vulnerable 'hotspot' nations in Asia and Africa, based on a systematic review of the peer-reviewed and grey literature, as well as policy documents, to extract evidence of adaptation initiatives. In total, 100 peer-reviewed articles, 161 grey literature documents, and 27 United Nations Framework Convention on Climate Change National Communications were reviewed, constituting 760 adaptation initiatives. Results indicate a significant increase in reported adaptations since 2006. Adaptations are primarily being reported from African and low-income countries, particularly those nations receiving adaptation funds, involve a combination of groundwork and more concrete adaptations to reduce vulnerability, and are primarily being driven by national governments, NGOs, and international institutions, with minimal involvement of lower levels of government or collaboration across nations. Gaps in our knowledge of adaptation policy and practice are particularly notable in North Africa and Central Asia, and there is limited evidence of adaptation initiatives being targeted at vulnerable populations including socioeconomically disadvantaged populations, children, indigenous peoples, and the elderly. [ABSTRACT FROM AUTHOR]

Malaria is a climate sensitive disease that is causing rampant deaths in sub-Saharan Africa (SSA) and its impact is expected to worsen under climate change. Thus, pre-emptive policies for future malaria control require projections based on integrated models that can accommodate complex interactions of both climatic and non-climatic factors that define malaria landscape. In this paper, we combined Geographical Information System (GIS) and Bayesian belief networks (BBN) to generate GIS-BBN models that predicted malaria hotspots in 2030, 2050 and 2100 under representative concentration pathways (RCPs) 4.5 and 8.5. We used malaria data of children of SSA, gridded environmental and social-economic data together with projected climate data from the 21 Coupled Model Inter-comparison Project Phase 5 models to compile the GIS-BBN models. Our model on which projections were made has an accuracy of 80.65% to predict the high, medium, low and no malaria prevalence categories correctly. The non-spatial BBN model projection shows a moderate variation in malaria reduction for the high prevalence category among RCPs. Under the low prevalence category, an increase in malaria is seen but with little variation ranging between 4.6 and 5.6 percentage points. Spatially, under RCP 4.5, most parts of SSA will have medium malaria prevalence in 2030, while under RCP 8.5, most parts will have no malaria except in the highlands. Our BBN-GIS models show an overall shift of malaria hotspots from West Africa to the eastern and southern parts of Africa especially under RCP 8.5. RCP 8.5 will not expand the high and medium malaria prevalence categories in all the projection years. The generated probabilistic maps highlight future malaria hotspots under climate change on which pre-emptive policies can be based. [ABSTRACT FROM AUTHOR]

• English-only searches for African climate change science introduce language-bias. • Non-English literature is poorly represented on Web of Science and Scopus. • Google Scholar incorporates a non-English voice, important for global assessments. • Supporting non-English authors may improve the global uptake of their work. • English-language research translated into local languages may encourage local use. Disregarding research not published in English may pose a risk to finding solutions for urgent global concerns, such as biodiversity loss, or climate change. To assess the extent of this 'missing voice', we compared the representation of 22 languages in scientific publications on climate change in Africa, indexed by widely used databases. Between 87 % and 95 % of publications were in English, with a small, but noteworthy, number in languages of the former European colonisers of Africa. We then assessed undergraduate monographs, master's dissertations, doctoral theses, and peer-reviewed papers derived from the doctoral theses, that are about Lusophone Africa and written in Portuguese, and found this research largely not accessible in English on online databases. If the goal of researchers, practitioners and policy makers is to obtain climate change information on, or present solutions for, individual developing countries, cultures, or localised issues, then searching in English may exclude local, context specific knowledge. This may prevent global assessments from being truly global, or locally down-scalable, by biasing science towards a single world view that marginalises key local stakeholders. [ABSTRACT FROM AUTHOR]

This article sets discourse by demonstrating the utility of indigenous climate knowledge (ICK) in understanding the science of climate change in Muzarabani, a rural community north of Zimbabwe. It argues that the notion of sacredness, enshrined in customary arrangements and belief systems, offers opportunities for exploitation in climate science. Through customary law, communities understand the sanctity and inviolability of the environment because of the varied cultural, political and ecological benefits derived from it. This perspective, although facing perpetuity challenges in Africa, can be exploited both to enhance understanding of climate change and to promote sustainable intervention strategies. By drawing from the experiences of indigenous people through in-depth conservations with a selected elderly local group, the paper proves that ICK offers capabilities in informing climate science. The local people have a range of sacred sites and environmental assets that can be used to understand past, current, and future climate systems from their many years of interactions with the same. Sacred forests and trees are also vital in climate change mitigation. It is concluded that, albeit limitations in scale, opportunities exist for tapping from the sacredness notions, to enhance the praxis of mitigation strategies such as Reducing Emissions from Deforestation and Forest Degradation (REDD+). [ABSTRACT FROM AUTHOR]

There is an increasing recognition of the role of climate change adaptation among smallholder farmers in rain-fed agriculture in Africa. Collective action among smallholder farmers has been suggested as influencing local adaptation processes hence the need to evaluate its impact in different contexts. This paper provides evidence of collective action in enhancing local adaptation to climate variability. It determines the importance of different forms of collective action for enhancing adaptation. Through simple random sampling, a survey of 240 households in Embu County in Kenya and 200 households from Kapchorwa district of Uganda was undertaken. Focus-group discussions involving farmer groups and local government representatives were performed to triangulate information collected through the surveys. The results show a positive relationship between membership in farmer groups and adaptation to climate variability in both sites. Four main components of collective action were identified in Embu and these included the development of internal group capacities, assets mobilization and management, collective marketing, and management of human and natural capital. In Kapchorwa, the development of internal group capacities, risk spreading, and financial resources were significant. We argue that local-level governance and institutional arrangements for collective action are critical for successful adaptation to climate variability. [ABSTRACT FROM PUBLISHER]

Climate change adaptation now occupies central stage on the agenda of most environmental initiatives in Africa. Our current understanding on the state of adaptation is limited, however, both globally and in Africa in particular. This study examines the status of adaptation in the Sahel by reviewing the primary peer review literature that reports concrete climate change adaptation actions. Based on an analysis of 70 peer review papers that document 414 discrete adaptations, we create a snap shot of adaptations developed between 1975 and 2015, and also calculate the percentages of adaptation. The results show that from a country to country perspective, Kenya has the highest number of reported adaptation actions (75 or 18.1%). The percentages indicate that the adaptive capacity of the entire study area is generally low for all the countries being that the highest country-level percentage is recorded in Kenya and it is 18%. Regionally, West Africa has more adaptation actions (261 or 63%) when compared to other regions of the Sahel. Regional level percentages suggest a higher level of adaptation at the regional level being that the percentage falls within the high scale range. The most commonly used adaptation actions reported are income diversification and water harnessing respectively. When categorized, technically related adaptation actions dominate the adaptation charts. The decade 2008–2016 recorded the highest number of adaptations (65.2%). Adaptation actions are also reported to be triggered by climatic and non-climatic drivers which both record high frequencies but the climatic drivers (98%) of adaptation are slightly dominant relative to the non-climatic drivers (95%). These results should be viewed as proxies of climate change adaptation as much information may be found in grey literature and non-peer review national communications which are left out here because of their relative low standardization and acceptability due to the absence of peer review. [ABSTRACT FROM AUTHOR]

Climate change is expected to have important implications for human mobility. This article discusses and contextualizes key insights from a recently published study by Thalheimer, Williams, van der Geest, and Otto in Earth's Future (2021), https://doi.org/10.1029/2020EF001958. The authors synthesize findings from the climate science and impact literature, among others from the IPCC Special Report on Global Warming of 1.5 °C, to explore the role of climatic drivers for human mobility in African drylands. Facing a number of economic, social, and political challenges, these areas are highly vulnerable to global warming and related risks. Climate mobility in this region is the outcome of complex interactions between individual and contextual factors shaping peoples' needs and incentives to move as well as their constraints. As the authors highlight, climate change can influence mobility outcomes through a number of channels, including impacts on food and water security, poverty and livelihood risks, and conflicts. These impacts are relevant for both rural areas and cities, with the latter representing a primary destination for climate‐induced migration in Africa. The complexity and diversity of the climate mobility nexus call for integrative approaches in science and policy that bridge different disciplines and policy sectors. These approaches should be based on fair, equal, and inclusive processes of knowledge production, transfer, and implementation that involve a number of stakeholders. Inclusive deliberations and partnerships across fields and sectors are key elements to comprehensively studying and addressing the realities and manifold challenges faced by both mobile and immobile populations. Key Points: Drylands in Africa are highly exposed and vulnerable to climate change impacts with important implications for human mobilityClimate mobility is the outcome of complex interactions between individual and contextual factors shaping mobility decisions, outcomes, and risksIntegrative approaches in science and policy are needed to address the complex nexus between climate change and human mobility [ABSTRACT FROM AUTHOR]

This systematic review analyzes all 260 studies published in the Web of Science on gender and climate change in Africa. While there is no strong methodological bias, comparative case studies and sex disaggregated analyses predominate from a limited set of countries. Many articles covered the agrarian sector by comparing women's and men's on-farm vulnerability to a changing climate based on their adaptation behaviours. Though this literature recognizes women's important conservation, farming, and food responsibilities, it oftentimes generalized these contributions without providing evidence. A number of themes were covered by a very limited number of articles, including coastal areas, conflict, education, energy, migration, urban areas, and water. Overall, more justice-oriented research is needed into the socioeconomic structures that intersect with social identities to make certain people, places, and institutions more vulnerable. Investigations into the power dynamics between (social) scientists and African institutions are also needed as most articles reviewed stem from North America and Europe and are locked beyond paywalls. [ABSTRACT FROM AUTHOR]

The cycad aulacaspis scale, Aulacaspis yasumatsui Takagi (Hemiptera: Coccoidea: Diaspididae), is native to Southeast Asia but an invasive pest of the gymnosperm order Cycadales in many parts of the world. Aulacaspis yasumatsui was recently reported on the cycad genus Encephalartos in South Africa and is currently categorized as a 'prohibited terrestrial invertebrate' in the invasive species legislation, National Environmental Management: Biodiversity Act, 2004 (NEM:BA). Encephalartos is endemic to Africa, and 11 species are listed as critically endangered and four species as endangered. Seeing the limited distribution of A. yasumatsui in South Africa and only one unconfirmed record from the Ivory Coast, understanding the potential distribution range is essential for control and management. Here we model the potential distribution of A. yasumatsui under current and future climate scenarios in Africa, with a focus on South Africa. Future climatic scenarios were simulated using a bio-climatic software, CLIMEX. The model indicates that, under the current climatic scenario, all 17 African countries possessing Encephalartos are susceptible to A. yasumatsui establishment. However, under climatic change, the suitability decreases for large parts of Africa. In South Africa, 93% of the winter rainfall areas, and 90% of the temperate, summer rainfall areas are suitable for A. yasumatsui establishment. In this study, we highlight the urgent need for regulation, management, and research on A. yasumatsui in African countries with native cycads. [ABSTRACT FROM AUTHOR]

The supereruption of Los Chocoyos (14.6 ∘ N, 91.2 ∘ W) in Guatemala ∼84 kyr ago was one of the largest volcanic events of the past 100 000 years. Recent petrologic data show that the eruption released very large amounts of climate-relevant sulfur and ozone-destroying chlorine and bromine gases (523±94 Mt sulfur, 1200±156 Mt chlorine, and 2±0.46 Mt bromine). Using the Earth system model (ESM) of the Community Earth System Model version 2 (CESM2) coupled with the Whole Atmosphere Community Climate Model version 6 (WACCM6), we simulated the impacts of the sulfur- and halogen-rich Los Chocoyos eruption on the preindustrial Earth system. Our simulations show that elevated sulfate burden and aerosol optical depth (AOD) persists for 5 years in the model, while the volcanic halogens stay elevated for nearly 15 years. As a consequence, the eruption leads to a collapse of the ozone layer with global mean column ozone values dropping to 50 DU (80 % decrease) and leading to a 550 % increase in surface UV over the first 5 years, with potential impacts on the biosphere. The volcanic eruption shows an asymmetric-hemispheric response with enhanced aerosol, ozone, UV, and climate signals over the Northern Hemisphere. Surface climate is impacted globally due to peak AOD of >6 , which leads to a maximum surface cooling of >6 K, precipitation and terrestrial net primary production decrease of >25 %, and sea ice area increases of 40 % in the first 3 years. Locally, a wetting (>100 %) and strong increase in net primary production (NPP) (>700 %) over northern Africa is simulated in the first 5 years and related to a southward shift of the Intertropical Convergence Zone (ITCZ) to the southern tropics. The ocean responds with pronounced El Niño conditions in the first 3 years that shift to the southern tropics and are coherent with the ITCZ change. Recovery to pre-eruption ozone levels and climate takes 15 years and 30 years, respectively. The long-lasting surface cooling is sustained by an immediate increase in the Arctic sea ice area, followed by a decrease in poleward ocean heat transport at 60 ∘ N which lasts up to 20 years. In contrast, when simulating Los Chocoyos conventionally by including sulfur and neglecting halogens, we simulate a larger sulfate burden and AOD, more pronounced surface climate changes, and an increase in column ozone. By comparing our aerosol chemistry ESM results to other supereruption simulations with aerosol climate models, we find a higher surface climate impact per injected sulfur amount than previous studies for our different sets of model experiments, since the CESM2(WACCM6) creates smaller aerosols with a longer lifetime, partly due to the interactive aerosol chemistry. As the model uncertainties for the climate response to supereruptions are very large, observational evidence from paleo archives and a coordinated model intercomparison would help to improve our understanding of the climate and environment response. [ABSTRACT FROM AUTHOR]

The need for the development of adaptation strategies for climate change in Africa is becoming critical. For example, infrastructure with a long lifespan now needs to be designed or adapted to account for a future climate that will be different from the past or present. There is a growing necessity for the climate information used in decision making to change from traditional science-driven metrics to decision-driven metrics. This is particularly relevant in East Africa, where limited adaptation and socio-economic capacity make this region acutely vulnerable to climate change. Here, we employ an interdisciplinary consultation process to define and analyse a number of such decision-oriented metrics. These metrics take a holistic approach, addressing the key East African sectors of agriculture, water supply, fisheries, flood management, urban infrastructure and urban health. A multifaceted analysis of multimodel climate projections then provides a repository of user-focused information on climate change and its uncertainties, for all metrics and seasons and two future time horizons. The spatial character and large intermodel uncertainty of changes in temperature and rainfall metrics are described, as well as those of other relevant metrics such as evaporation and solar radiation. Intermodel relationships amongst metrics are also explored, with two clear clusters forming around rainfall and temperature metrics. This latter analysis determines the extent to which model weights could, or could not, be applied across multiple climate metrics. Further work must now focus on maximising the utility of model projections, and developing tailored risk-based communication strategies. [ABSTRACT FROM AUTHOR]

Modes of climate variability are known to influence rainy season onset, but there is less understanding of how they impact flood timing. We use streamflow reanalysis and gauged observation data sets to examine the influence of the Indian Ocean Dipole and El Niño–Southern Oscillation across sub‐Saharan Africa. We find significant changes in flood timing between positive and negative phases of both Indian Ocean Dipole and El Niño–Southern Oscillation; in some cases the difference in the timing of annual flood events is more than three months. Sensitivity to one or other mode of variability differs regionally. Changes in flood timing are larger than variability in rainy season onset reported in the literature, highlighting the need to understand how the hydrological system alters climate variability signals seen in rainy season onset, length, and rainfall totals. Our insights into flood timing could support communities who rely on flood‐based farming systems to adapt to climate variability. Plain Language Summary: Patterns of climate variability such as the El Niño–Southern Oscillation or the Indian Ocean Dipole affect the timing of the start of the rainy season, but little is known about how this translates into changes in the timing of the annual flood in rivers. We use computer model reconstructions and observed records of river flows in Africa to understand how these patterns of climate variability are changing the timing of river floods. In eastern and southern Africa, in particular, the differences in flood timing can be more than three months. This information could help farmers in African floodplains to adapt their water management, planting, and cropping practices to these patterns of climate variability. Key Points: Modes of climate variability in the Pacific and Indian Oceans drive significant changes in flood timing across sub‐Saharan AfricaThe hydrological system enhances and alters climate variability signals seen in rainy season onset, duration, and total rainfallUnderstanding of how climate variability changes the timing of floods can support flood‐based farming systems [ABSTRACT FROM AUTHOR]

Climate-related studies have generally focussed upon physiologically well-defined ‘mechanistic’ traits rather than ‘functional’ ones relating indirectly to resource capture. Nevertheless, field responses to climate are likely to typically include both ‘mechanistic’ specialization to climatic extremes and ‘functional’ strategies that optimize resource acquisition during less climatically-severe periods. Here, this hypothesis was tested. Seventeen traits (six ‘functional’, six ‘mechanistic’ and five ‘intermediate’) were measured from 19 populations of oleaster (wild olive) along a climatic gradient in Morocco. Principal components analysis of the trait dataset identified size and the ‘worldwide leaf economics spectrum’ as PCA axes 1 and 2. However, contrary to our prediction, these axes, and commonly-measured ‘functional’ traits, were little correlated with climate. Instead, PCA 3, perhaps relating to water-use and succulence, together stomatal density, specific leaf water content and leaf shape, patterned with altitude, aridity, rainfall and temperature. We concluded that, at least for slow-growing species, such as oleaster, ‘mechanistic’ traits are key to identifying mechanisms of climatic restriction. Meaningful collaboration between ‘mechanistic’ and ‘functional’ disciplines provides the best way of improving our understanding of the global impacts of climate change on species distribution and performance. [ABSTRACT FROM AUTHOR]

This study assessed households’ resilience to climate change-induced shocks in Dinki watershed, northcentral highlands of Ethiopia. The data were collected through a cross-sectional survey conducted on 288 households, three focus group discussions, and 15 key informant interviews. The Climate Resilience Index (CRI) based on the three resilience capacities (absorptive, adaptive and transformative) frame was used to measure households’ resilience to climate change-induced shocks on an agro-ecological unit of analysis. A principal component analysis (PCA) and multiple regression analysis were used to identify determinant factors and indicators to households’ resilience, respectively. Findings indicate that the indexed scores of major components clearly differentiated the study communities in terms of their agro-ecological zones. Specifically, the absorptive capacity (0.495) was the leading contributing factor to resilience followed by adaptive (0.449) and transformative (0.387) capacities. Likewise, the Midland was relatively more resilient with a mean index value of 0.461. Both the PCA and multiple regression analysis indicated that access to and use of livelihood resources, such as farmlands and livestock holdings, diversity of income sources, infrastructure and social capital were determinants of households’ resilience. In general, it might be due to their exposure to recurrent shocks coupled with limited adaptive capacities including underdeveloped public services, poor livelihood diversification practices, among others, the study communities showed minimal resilience capacity with a mean score of 0.44. Thus, in addition to short-term buffering strategies, intervention priority focusing on both adaptive and transformative capacities, particularly focusing on most vulnerable localities and constrained livelihood strategies, would contribute to ensuring long-term resilience in the study communities. [ABSTRACT FROM AUTHOR]

Background: The increase in the frequency of extreme events due to climate change poses a serious challenge to achieving the Sustainable Development Goal 2 of ending hunger by 2030. While evidence exists on the impact of drought on under-five children, its effect during late childhood and early adolescence remains less investigated. Objective: This study estimates the impact of concurrent and long-term exposure to drought on linear growth during late childhood and early adolescence. Methods: Four rounds (2002–2013) of data from the young lives Cohort Study dataset (n = 2000) was used. The associations of concurrent and long-term exposure to drought and Height-for-age z-score was analysed using structural equation modelling techniques. The study also explored the mediating role of interim period growth in the association of early exposure to drought and undernutrition at later age and the role of the Productive Safety Net Program in buffering the impact of drought on child nutrition. Results: Results show that both concurrent and long-term exposure to drought was negatively associated with Height-for-age z-score (p < 0.001). Exposure to drought at age 5, 8, and 12 years is associated with lower Height-for-age z- score at age 5, 8, and 12 years respectively. Exposure to drought at age 5 years was also negatively associated with Height-for-age z-score at age 12 years (p < 0.001). This association was mainly indirect (89%) and mediated through reduced child growth in subsequent years. Participation in productive safety net program by drought-affected children reduces but does not completely offset the negative effects of drought on Height-for-age z-score (p < 0.1). Moreover, girls were more likely to suffer poor growth than boys. Conclusion: Drought exposure after the 1,000 days window could have a lasting impact on child growth. Given the importance of this period for child physical and mental development, children beyond the 1,000 days window should also be a focus of disaster relief programs. [ABSTRACT FROM AUTHOR]

The North African Coastal Low-Level Jet (NACLLJ) is a semi-permanent feature offshore the north western African coast, linked to the cold nearshore upwelling of the Canary Eastern Boundary Current system. Its main synoptic drivers are the Azores Anticyclone over the ocean and the inland Sahara thermal low. The coastal jet events occur in one of the world's most productive fisheries region, thus the evaluation of the effects of global warming in its properties is imperative. This study proposes an analysis of the annual and intra-annual attributes of the NACLLJ for two time periods 1976–2005 (historical) and 2070–2199 (future), resorting to coupled and uncoupled atmosphere–ocean simulations with the ROM model, as well as near surface offshore wind speed from the CORDEX-Africa ensemble. The future simulations follow the RCP8.5 greenhouse gas emissions scenario. Overall, the ROM coupled simulation presents the best performance in reproducing the present-climate near surface wind speed, offshore northwest Africa, compared to the remaining RCM simulations. The higher SST resolution in the coupled simulations favours much localised colder upwelling strips near the coast and consequently stronger jets. In future climate, a small increase in the surface wind speed is projected, mainly linked to the regions of coastal jet presence. The NACLLJ is projected to be more frequent and intense, encompassing larger areas. An increase of the jet seasonal frequencies of occurrence is projected for all seasons, which is larger from spring to autumn (up to 15, 16 and 22% more frequent, respectively). However, in some offshore areas the winter NACLLJ persistency is likely to double, relatively to present-climate. Higher inter-annual variability is also projected for the future NACLLJ seasonal frequencies. The strengthening of the coastal jet speeds is also significant, between 5 and 12% in all seasons. Additionally, the jet's diurnal cycle shows an increase in jet occurrence across the day, particularly in the mid and late afternoon. [ABSTRACT FROM AUTHOR]

Acute gastrointestinal illness (AGI) is a global public health priority that often disproportionately effects Indigenous populations. While previous research examines the association between meteorological conditions and AGI, little is known about how socio-cultural factors may modify this relationship. This present study seeks to address this research gap by comparing AGI prevalence and determinants between an Indigenous and non-Indigenous population in Uganda. We estimate the 14-day self-reported prevalence of AGI among adults in an Indigenous Batwa population and their non-Indigenous neighbours using cross-sectional panel data collected over four periods spanning typically rainy and dry seasons (January 2013 to April 2014). The independent associations between Indigenous status, precipitation, and AGI are examined with multivariable multi-level logistic regression models, controlling for relative wealth status and clustering at the community level. Estimated prevalence of AGI among the Indigenous Batwa was greater than among the non-Indigenous Bakiga. Our models indicate that both Indigenous identity and decreased levels of precipitation in the weeks preceding the survey period were significantly associated with increased AGI, after adjusting for confounders. Multivariable models stratified by Indigenous identity suggest that Indigenous identity may not modify the association between precipitation and AGI in this context. Our results suggest that short-term changes in precipitation affect both Indigenous and non-Indigenous populations similarly, though from different baseline AGI prevalences, maintaining rather than exacerbating this socially patterned health disparity. In the context of climate change, these results may challenge the assumption that changing weather patterns will necessarily exacerbate existing socially patterned health disparities. [ABSTRACT FROM AUTHOR]

Forecasting the impacts of climate change on Aedes-borne viruses—especially dengue, chikungunya, and Zika—is a key component of public health preparedness. We apply an empirically parameterized model of viral transmission by the vectors Aedes aegypti and Ae. albopictus, as a function of temperature, to predict cumulative monthly global transmission risk in current climates, and compare them with projected risk in 2050 and 2080 based on general circulation models (GCMs). Our results show that if mosquito range shifts track optimal temperature ranges for transmission (21.3–34.0°C for Ae. aegypti; 19.9–29.4°C for Ae. albopictus), we can expect poleward shifts in Aedes-borne virus distributions. However, the differing thermal niches of the two vectors produce different patterns of shifts under climate change. More severe climate change scenarios produce larger population exposures to transmission by Ae. aegypti, but not by Ae. albopictus in the most extreme cases. Climate-driven risk of transmission from both mosquitoes will increase substantially, even in the short term, for most of Europe. In contrast, significant reductions in climate suitability are expected for Ae. albopictus, most noticeably in southeast Asia and west Africa. Within the next century, nearly a billion people are threatened with new exposure to virus transmission by both Aedes spp. in the worst-case scenario. As major net losses in year-round transmission risk are predicted for Ae. albopictus, we project a global shift towards more seasonal risk across regions. Many other complicating factors (like mosquito range limits and viral evolution) exist, but overall our results indicate that while climate change will lead to increased net and new exposures to Aedes-borne viruses, the most extreme increases in Ae. albopictus transmission are predicted to occur at intermediate climate change scenarios. [ABSTRACT FROM AUTHOR]

The study examines the perceived added value of downscaling atmosphere-ocean global climate model simulations over Africa and adjacent oceans by a nested regional climate model. NASA/Goddard Institute for Space Studies (GISS) coupled ModelE simulations for June-September 1998-2002 are used to form lateral boundary conditions for synchronous simulations by the GISS RM3 regional climate model. The ModelE computational grid spacing is 2° latitude by 2.5° longitude and the RM3 grid spacing is 0.44°. ModelE precipitation climatology for June-September 1998-2002 is shown to be a good proxy for 30-year means so results based on the 5-year sample are presumed to be generally representative. Comparison with observational evidence shows several discrepancies in ModelE configuration of the boreal summer inter-tropical convergence zone (ITCZ). One glaring shortcoming is that ModelE simulations do not advance the West African rain band northward during the summer to represent monsoon precipitation onset over the Sahel. Results for 1998-2002 show that onset simulation is an important added value produced by downscaling with RM3. ModelE Eastern South Atlantic Ocean computed sea-surface temperatures (SST) are some 4 K warmer than reanalysis, contributing to large positive biases in overlying surface air temperatures (Tsfc). ModelE Tsfc are also too warm over most of Africa. RM3 downscaling somewhat mitigates the magnitude of Tsfc biases over the African continent, it eliminates the ModelE double ITCZ over the Atlantic and it produces more realistic orographic precipitation maxima. Parallel ModelE and RM3 simulations with observed SST forcing (in place of the predicted ocean) lower Tsfc errors but have mixed impacts on circulation and precipitation biases. Downscaling improvements of the meridional movement of the rain band over West Africa and the configuration of orographic precipitation maxima are realized irrespective of the SST biases. [ABSTRACT FROM AUTHOR]

The population of the Sahel region of West Africa has approximately doubled in the past 50 years, and could potentially double again by the middle of this century. This has led to the northward expansion of agricultural areas at the expense of natural savanna, leading to widespread land use -land cover change (LULCC). Because there is strong evidence of significant surface-atmosphere coupling in this region, one of the main goals of the West African Monsoon Modeling and Evaluation project phase II is to provide basic understanding of LULCC on the regional climate, and to evaluate the sensitivity of the seasonal variability of the West African Monsoon to LULCC. The prescribed LULCC is based on the changes from 1950 through 1990, representing a maximum feasible degradation scenario in the past half century. It is applied to 5 state of the art global climate models (GCMs) over a 6-year simulation period. Multiple GCMs are used because the magnitude of the impact of LULCC depends on model-dependent coupling strength between the surface and the overlying atmosphere, the magnitude of the surface biophysical changes, and how the key processes linking the surface with the atmosphere are parameterized within a particular model framework. Land cover maps and surface parameters may vary widely among models; therefore a special effort was made to impose consistent biogeophysical responses of surface parameters to LULCC using a simple experimental setup. The prescribed LULCC corresponds to degraded vegetation conditions, which mainly cause increases in the Bowen ratio and decreases in the surface net radiation, and result in a significant reduction in surface evaporation (upwards of 1 mm day over a large part of the Sahel). This, in turn, mainly leads to less moisture convergence and precipitation over the LULCC zone. The overall impact is a rainfall reduction with every model, which ranges across models from 4 to 25 % averaged over the Sahel, and a southward shift of the rainfall peak in three of the five models which evokes a precipitation dipole pattern which is consistent with the observed pattern for dry climate anomalies over this region. The African Easterly Jet shifts equator-ward, although the strength of this change varies considerably among the models. In most of the models, the main factor causing diabatic cooling of the upper troposphere and enhanced subsidence over the region of LULCC is the reduction of convective heating rates linked to reduced latent heat flux and moisture flux convergence. In broad agreement with previous studies, the impact of degradation on the regional climate is found to vary among the different models, however, the signal is stronger and more consistent between the models here than in previous inter-comparison projects. This is likely related to our emphasis on prioritizing a consistent impact of LULCC on the surface biophysical properties. [ABSTRACT FROM AUTHOR]