To date, no observation-based proxy for climate change has been successful in quantifying the feedbacks between clouds and climate. The most promising, yet demanding, avenue to gain confi dence in cloud–climate feedback estimates is to utilize observations and large-eddy simulations (LES) or cloud-resolving modeling (CRM) to improve cloud process parameterizations in large-scale models. Sustained and improved satellite observations are essential to evaluate large-scale models. A reanalysis of numerical prediction models with assimilation of cloud, aerosol, and precipitation observations would provide a valuable dataset for examining cloud interactions. The link between climate modeling and numerical weather prediction (NWP) may be exploited by evaluating how accurate cloud characteristics are represented by the parameterization schemes in NWP models. A systematic simplifi cation of large-scale models is an important avenue to isolate key processes linked to cloud–climate feedbacks and would guide the formulation of testable hypotheses for fi eld studies. Analyses of observation-derived correlations between cloud and aerosol properties in combination with modeling studies may allow aerosol–cloud interactions to be detected and quantifi ed. Reliable representations of cloud dynamic and physical processes in large-scale models are a prerequisite to assess aerosol indirect effects on a large scale with confi dence. To include aerosol indirect effects in a consistent manner, we recommend that a “radiative fl ux perturbation” approach be considered as a complement to radiative forcing.

To date, no observation-based proxy for climate change has been successful in quantifying the feedbacks between clouds and climate. The most promising, yet demanding, avenue to gain confi dence in cloud–climate feedback estimates is to utilize observations and large-eddy simulations (LES) or cloud-resolving modeling (CRM) to improve cloud process parameterizations in large-scale models. Sustained and improved satellite observations are essential to evaluate large-scale models. A reanalysis of numerical prediction models with assimilation of cloud, aerosol, and precipitation observations would provide a valuable dataset for examining cloud interactions. The link between climate modeling and numerical weather prediction (NWP) may be exploited by evaluating how accurate cloud characteristics are represented by the parameterization schemes in NWP models. A systematic simplifi cation of large-scale models is an important avenue to isolate key processes linked to cloud–climate feedbacks and would guide the formulation of testable hypotheses for fi eld studies. Analyses of observation-derived correlations between cloud and aerosol properties in combination with modeling studies may allow aerosol–cloud interactions to be detected and quantifi ed. Reliable representations of cloud dynamic and physical processes in large-scale models are a prerequisite to assess aerosol indirect effects on a large scale with confi dence. To include aerosol indirect effects in a consistent manner, we recommend that a “radiative fl ux perturbation” approach be considered as a complement to radiative forcing.

MENVSC / Department of Geography and Geo-Information Sciences / Many rural communities of South Africa are living without adequate water supplies mainly due to historical lack of infrastructure and effective water reticulation systems. Day to day challenges of accessing water from distant boreholes and rivers are a reality particularly for women and children in rural Limpopo. This study investigates the nature and extent of water supply problems and how communities are living without adequate water in three rural communities of Greater-Giyani Local Municipality in South Africa. The study area lies in a semi-arid region which regularly experiences climate extremes such as droughts and floods which can reduce the ability of the municipality to supply water. Primary data was collected through questionnaires, key informant interviews and field observations while population, climate and hydrological data are also analyzed. A mixed methods research design was employed using qualitative methods such as content analysis whilst quantitative methods were dominated by time series analysis techniques and online interactive climate platforms such as the Climate Engine. It was found that households, schools and clinics in the study area rely mainly on boreholes for water supply but sometimes rivers supply those living nearby. An incomplete and poor water reticulation system coupled with erratic and shortening summer rainfall seasons are some of the major causes of water shortages in the study area. In order to cope with inadequate water, community members and public institutions in the study area have drilled boreholes and the sustainability of groundwater in the area is not well established. During summer, most households and institutions practise rainwater harvesting while a few resort to purchasing water from vendors. Despite these challenges which are not well documented, it was concluded that most of the rural poor households and institutions in the study area are well adapted to cope with water scarcity in the short term, while being vulnerable in the long term due to population growth and climate change. The study recommends the need for government and municipalities to invest in water reticulation systems in the long term whilst providing water to affected rural communities through water tankers, drilling more boreholes and maintenance of existing ones. Lessons learnt from this study may be useful to other municipalities across South Africa that are grappling with challenges of water access and supply. / NRF