ramin and mcmichael ( 2 ) , acknowledging the paucity of evidence - based results , present five hypothetical case studies illustrating what they believe to be the major issues . these are concerned with the interaction between hiv and rain - fed food production capacity ; impact of drought on child nutrition ; disease impact of floods ; changing patterns of malaria transmission ; and the impact of natural disasters . however , these but serve as examples of scenarios which are all too rarely documented in detail with a basis in reliable data . much more attention has been given to global and regional estimates , using multiple data sources and models , of possible changes in climate and , in some cases , their potential health consequences . the stern report ( 3 ) paints a gloomy picture for africa , concluding that  the poorest will be hit earliest and most severely . in many developing countries , even small amounts of warming will lead to declines in agricultural production because crops are already close to critical temperature thresholds . the human consequences will be most serious and widespread in sub - saharan africa , where millions more will die from malnutrition , diarrhoea , malaria and dengue fever , unless effective control measures are in place. this is also reflected in the recent ucl lancet commission report ( 4 ) , which suggests that the highest regional burden of climate change is likely to be borne by sub - saharan africa , with 34% of the global disability adjusted life years ( dalys ) attributable to climate change located there . since sub - saharan africa only contains 11% of the world 's population ( 5 ) , this reflects a three - fold population - based risk for adverse effects of climate change among africans compared with the global population . a review of likely impacts of climate change on food insecurity ( 6 ) concludes that current estimates of climate change will probably lead to greater risk of hunger , particularly in africa , but without going on to consider the likely population health impacts of such hunger . changes in land use , either forced by climate change or in response to environmental pressures , may also impact on food security ( 7 ) . infectious diseases tend to be considered first when contemplating the effects of climate change on health ( 1 ) , but these may not be the only or even the major factor ; impacts such as the physiological effects of heat may be equally important ( 8) , particularly on the african continent where large proportions of people are regularly exposed to extremes of high temperature . a review of cholera seasonality globally from 1974 to 2005 ( 9 ) suggests that climate change may well lead to less predictable patterns of cholera outbreaks ; within africa this is likely to be seen more in northern and western areas rather than in the equatorial zone . detailed analyses of diarrhoeal disease patterns in benin ( 10 ) have established expected relationships between risks of diarrhoea and lack of good - quality water supplies . these authors go on to suggest that the consequences of future climate change scenarios , leading to large - scale population displacements , may be predicated on resource considerations , such as water supply , at migratory destinations . whilst changes in climate may have impacts on distributions of vector - borne diseases as a direct consequence of ecological pressure on vectors , it is also important to take into account changes in host factors , such as exposure and immunity , in considering health consequences ( 11 ) . furthermore , the disease manifestations of longer - term epidemiological changes driven by climate may be masked by adaptational mechanisms in human populations ( 12 ) . part of this seems to derive from concerns that the global range of malaria may be extended as territories outside current endemic zones become wetter and warmer , rather than concerns about africa per se , even if these concerns may in some cases have been overstated ( 13 ) . detailed climatic analyses suggest that patterns of malaria transmission in africa may well change as a result of climate changes ( 14 ) . these changes are modulated by altitude , and the interactions between climate , altitude and vector behaviour ( 15 ) . the general notion that climate is changing , alongside observations of changes in malaria disease patterns , do not , however , necessarily constitute a cause and effect relationship between climate change and malaria ( 16 ) . the importance of carrying through climate modelling into vector dynamics modelling has been stressed ( 17 ) . some predictions suggest that the main effect of climate change on malaria in africa will be geographic shifts of transmission within the continent , rather than overall changes ( 18 ) . examples of local impacts on overall population health in africa as a consequence of climate change are relatively rare , not least because of the relative scarcity of detailed health data from the african continent in the first place ( 19 ) . after a series of debilitating rainfall failures in northern ethiopia , as well as being a response to climate variability , these new reservoirs generated their own microclimates , often including nearby villages and one consequence was a seven - fold increase in childhood malaria incidence near the dams ( 20 ) . in one district of burkina faso , detailed connections have been made between temperature , rainfall , mosquitoes and malaria , resulting in a local - level model relating climate to malaria transmission ( 21 ) . in central ethiopia , links have been made between erratic seasonal patterns of rainfall and disease epidemics which gave rise to a 2.5-fold increase in local overall population mortality over a two - year period ( 22 ) . scientific evidence connecting climate change and population health in africa remains scanty , both because of the lack of clear understanding of the progress and nature of climate change , and the widespread lack of community - based health data . by contrast , the heatwave experienced in western europe in 2003 was immediately identified as an unusual meteorological event and shortly afterwards analyses of resultant excess mortality were available , using data from routine systems ( 23 ) . although the dominance of malaria in the literature linking climate change and health in africa might lead one to suppose that it is the major issue , in fact other effects that are relatively under - documented may turn out to have numerically greater impacts as time passes . it may simply be the case that malaria has been the most researched issue in relation to climate thus far . however , if predictions of changing epidemic patterns of malaria within africa are borne out ( 18 ) , then the effects of new or increased endemicity among relatively less - immune populations could be severe , affecting all sectors within populations . apart from situations where interventions for other purposes facilitate the investigation of climate impacts ( such as the ethiopian microdams ( 20 ) ) , most research into the effects of climate change on population health has to essentially follow a process of making retrospective connections between meteorological data and health outcomes . population groups can not be randomised to different kinds of natural climate change , and hence drawing causal inferences between observed climatic variations and disease patterns is difficult to achieve with certainty . settings where prospective longitudinal population surveillance is in place , such as indepth network sites ( 24 ) , are likely to be particularly valuable for analysing the population effects of climate change in africa , since it is usually too late to collect health outcome data once a particular climate phenomenon has been observed . routine collection of meteorological data at such sites should be regarded as normative in the current era of climate change , as well as routinely geo - referencing population health data in order to make connections with external meteorological data ( 25 ) . even within such surveillance sites , prompt routine review procedures for incoming data are very important if major health - related events at the population level that might be climate - linked are to be spotted promptly ( 26 ) . perhaps the lack of potential for experimental study design in relating climate change to health in africa , as well as the practical difficulties of obtaining the necessary data , have led to the relative lack of detailed scientific output in the intersection between health and climate change in africa . the relatively weak research infrastructure in many african settings is a contributory problem , but , more importantly , cross - disciplinary work ( between climatology and health in this instance ) is not common in africa and needs to be actively promoted . expertise in applying global climate models regionally is very scarce in africa ( 27 ) , against the inevitable background of the world 's most sophisticated climatological research centres being northern - based . thus stronger links and capacity - building collaborations need to be forged between these global resources in the north and african health and climate research groups , if meaningful and useful scientific connections are going be made between climate change and health in africa . despite the dearth of research on the ground in africa so far , it seems clear from major global - level considerations of climate change and their possible effects on population health ( 3 , 4 ) that , yet again , africa and her people stand to come out worst from the likely changes in the world 's weather patterns . this has to be seen against a background of food and water security which is already at marginal levels in many places . this therefore constitutes a major challenge to governments in terms of future policy - making , and hence to universities and other research centres for generating the necessary evidence base . thus there are compelling reasons to promote and facilitate good quality and detailed research on climate change and population health in africa , in much larger quantities than heretofore . the author has not received any funding or benefits from industry to conduct this study .
despite a growing awareness of africans vulnerability to climate change , there is relatively little empirical evidence published about the effects of climate on population health in africa . 
 this review brings together some of the generalised predictions about the potential continent - wide effects of climate change with examples of the relatively few locally documented population studies in which climate change and health interact . 
 although ecologically determined diseases such as malaria are obvious candidates for susceptibility to climate change , wider health effects also need to be considered , particularly among populations where adequacy of food and water supplies may already be marginal .