Assessment and Projection of Climate Change Impacts on Malaria Distribution in Ethiopia: Case of Combolcha and Debark Districts

Abstract

The dynamics of Earth’s climate system have been affecting human life. Climate along with its variability and change had been observed laying impressive impacts on different socio-economic activities such as: agricultural, power generation, water supply, public health, social and political issues, (IPCC, 2015). An increase in greenhouse gases leads to increased warming of the atmosphere, ocean and the Earth’s surface. As a result, climate change become familiar in the past, present and future time, C. McSweeney et al 2006, Z. T. Segel et al 2008 & USAID 2015. Beside to this, H. F. DAIZ and R. S. BRADLEY, 1997 found evidence for appreciable differences in mean temperature changes with elevation during the last several decades. And, according to I. Rangwala & J. R. Miller, January 2012 the sensitivity of climate changes to surface elevations, is remarkable just like to the climate changes identified at a horizontal surface with fixed altitudes. Existing literature suggests that global warming or inter-annual/decadal climate variability have a direct influence on the epidemiology of vector-borne diseases. As WMO & WHO, Sept. 2015 of the Intergovernmental Panel on Climate Change (IPCC), anticipated changes in temperature and rainfall will affect the natural Abstract: Climate change has a significant impact on the environment, socio-economic as well as on public health, especially on the transmission of malaria disease. Some sources of facts display that while no precisely defined limit exists beyond which malaria will not be found, recently a malaria distribution case has been seen in high land areas of Eastern Africa (e.g. Ethiopian). In this study, we assess and predict the impact of climate change on elevation-dependent malaria distribution temporally over Combolcha and Debark districts which are high lands of Ethiopia where there was no the case in history. The method applied for assessment and projection of climate variability is statistical approach, in general. And for assessment and projection of climate driven malaria distribution, the method used was based on the intersection of the favorable climate parameters: Precipitation, Temperature and Relative Humidity with the suitable threshold values. Thus, gradual malaria expansion to higher altitudes is justified in association to climate change and variability. In the result, we determine that the change and variability in precipitation was more significant (0.64 correlation) in controlling malaria transmission than the temperature over relative lower elevation areas (Combolcha). On the reverse, the change and variability in temperature (0.53 correlation) takes the first place in controlling malaria transmission over Debark. Moreover, the result indicates that the climate change and variability allowed malaria transmission site potentially tending to elevate to the high lands of Ethiopia like Debark district, recently in 2015 and 2016. In addition, the altitude 2,800 m above mean sea level was determined to be the demarcation point-level above which the disease malaria could not existed in Debark woreda for the period (1986-2016). Again, this assessment result demonstrated malaria transmission site to reach at 2,800m while the result obtained using MARA13 malaria projection model puts the elevation at 2,500 m, for 2015. Finally, we conclude that due to the present and future climate change malaria occurred on recent-time over new places of Ethiopia, in particular over high lands of Debark district; and in future, there is an indication to malaria persist over 2,800m elevation and incident on beyond this topographical height.