Adaptation Advantage to Climate Change Impacts on Road Infrastructure in Africa through 2100

The African continent is facing the potential of a US$183.6 billion liability to repair and maintain roads damaged from temperature and precipitation changes related to climate change through 2100. As detailed, the central part of the continent faces the greatest impact from climate change with countries facing an average cost of US$22 million annually, if they adopt a proactive adaptation policy and a US$54 million annual average, if a reactive approach is adopted. Additionally, countries face an average loss of opportunity to expand road networks from a low of 22 per cent to a high of 235 per cent in the central region.infrastructure, climate change, roads, cost estimates

Regional climate change of the greater Zambezi River Basin: a hybrid assessment

Projections of regional changes in surface-air temperature and precipitation, in response to unconstrained emissions as well as a climate mitigation policy, for the Zambezi River Basin (ZRB) are presented. These projections are cast in a probabilistic context through a hybrid technique that combines the projections of the MIT Integrated Global System Model (IGSM) to pattern-change kernels from climate-model results of the Coupled Model Intercomparison Project (CMIP). Distributional changes of precipitation and surface-air temperature averaged over the western and eastern ZRB are considered. Overall, the most significant response to climate policy is seen in the spring. Frequency distributions of precipitation change for the unconstrained emission scenario indicate a majority of the outcomes to be drier by 2050, although the distribution spans both increased and decreased precipitation. Through climate policy, the distributions’ total range of outcomes collapses considerably, and perhaps more importantly, the mode of the distribution aligns with zero precipitation change. For surface-air temperature, climate policy consistently reduces the modal value of warming, and this reduction is strongest for the western ZRB. Climate policy also considerably abates the occurrence of the most extreme temperature increases, but the minimum warming in the distributions is less affected.United Nations University. World Institute for Development Economics ResearchMassachusetts Institute of Technology. Joint Program on the Science & Policy of Global Chang

The impacts of climate change on regional water resources and agriculture in Africa

This paper summarizes the methods and findings of the hydrological assessment component of the project studying likely impacts of climate change on water resources and agriculture in Africa. The first phase of the study used a version of a conceptual rainfall-runoff model called WatBal (Water Balance) applied to gridded data to simulate changes in soil moisture and runoff across the whole continent of Africa rather than to any particular catchment or water resource system. The model inputs were the climate variables of the 1961-90 climatology and physiological parameters (such as soil properties and land use) derived from global datasets for each of the 0.5 degree latitude/longitude cells across the continent. The primary model output comprised a time series (monthly time step) of simulated runoff for all the grid cells for each of the districts in the countries of interest. The second phase of the study extended the hydrology analyses to update the above hydroclimatic series to the year 2000 using updated input data. To ascertain the possible impacts of climate change within the districts being investigated this study used synthetic or GCM-based climate change scenarios as input to the WatBal model. The WatBal model was used to determine the impact of these different scenarios on runoff and actual evaporation and hence flow in the districts under study. The generated hydroclimatic series and scenario analyses were used as inputs into various Ricardian regressions in other analyses measuring likely impacts of climate change on the agricultural economies of Africa.Wetlands,Climate Change,Water Supply and Systems,Global Environment Facility,Common Property Resource Development

Inter-sectoral Water Use in South Africa: Efficiency Versus Equity

While water supply sources are dwindling in South Africa, the demand for the scarce water resource is increasing. This situation requires a switch from supply to demand management of water in the country. The study updates the 1999 social accounting matrix for South Africa, using the Trade and Industrial Policy Strategies (TIPS) time series data, STATSA's 2001 census report and 2000 water accounts, the 2002 national income accounts, published by the South African Reserve Bank (SARB) and the Water Resource Management Strategy (WRMS) registration data. Using the updated SAM, the contribution of water to economic development in South Africa is estimated through the traditional SAM multiplier analysis. The paper then investigates the impact of reallocating water among the production sectors, on the basis of economic efficiency, on output growth, factor remuneration and households' income generation. The computational and simulation results show that, though agriculture is among the sectors that have the least marginal value of water, water reallocation based on marginal values will reduce the incomes of the poorest households, and put at stake the livelihoods of the most vulnerable population. Scenario analyses suggest that this effect will be minimal if marginal productivity consideration for inter-sectoral water reallocation is reduced to 30%, while intra-sectoral water reallocation on the basis of efficiency is currently viewed as the most viable option.SAM multipliers, output growth, factor remuneration, income generation, efficiency, equity, R20, Resource /Energy Economics and Policy, C67, D57, L60, Q25,

Infrastructure and climate change: a study of impacts and adaptations in Malawi, Mozambique, and Zambia

The African Development Bank has called for $40 Billion USD per year over the coming decades to be provided to African countries to address development issues directly related to climate change. The current study addresses a key component of these issues, the effect of climate change on the road infrastructure of Malawi, Mozambique, and Zambia. The study incorporates a stressor-response approach to estimate the effects of projected precipitation, temperature, and flooding changes on the paved and unpaved road infrastructure of these countries. The paper highlights the result of running 425 climate scenarios for each road type and policy option from 2010 to 2050. Based on this broad analysis, it is estimated that the three southern African countries are facing a potential$596 million price tag based on median climate scenarios to maintain and repair roads as a result of damages directly related to temperature and precipitation changes from potential climate change through 2050. The challenge for policy makers is to determine the potential risk that a country is facing based on the uncertainties associated with the multiple aspects of climate change modeling. This article is part of a Special Issue on “Climate Change and the Zambezi River Valley” edited by Finn Tarp, James Juana, and Philip Ward

Households’ welfare analyses of the impact of global change on water resources in South Africa

Most of the climate change models for South Africa predict a reduction in freshwater availability by 2050. Population growth is projected at 3% per annum, implying increased domestic water use. In addition to these factors, the concern for ecological sustainability and increased water pollution due to increased industrial, mining and agricultural activities, water availability for sectoral production activities is expected to decline. This decline has an impact on sectoral output, value added and households’ welfare. Using a computable general equilibrium approach, this study investigates the possible impact of global change on households’ welfare. The simulation results show that water scarcity due to global change can potentially lead to a general deterioration in households’ welfare. The poor households, whose incomes are adversely impacted, are the most vulnerable to the consequences of the impact of global change on water resources in South Africa. This vulnerability can only be reduced if welfare policies that maintain food consumption levels for the least and low-income households are implemented.Resource /Energy Economics and Policy,

Impacts of considering climate variability on investment decisions in Ethiopia:

"Extreme interannual variability of precipitation within Ethiopia is not uncommon, inducing droughts or floods and often creating serious repercussions on agricultural and non-agricultural commodities. An agro-economic model, including mean climate variables, was developed to assess irrigation and road construction investment strategies in comparison to a baseline scenario over a 12-year time horizon. The motivation for this work is to evaluate whether the inclusion of climate variability in the model has a significant effect on prospective investment strategies and the resulting country-wide economy. The mean climate model is transformed into a variable climate model by dynamically adding yearly climate-yield factors, which influence agricultural production levels and linkages to non-agricultural goods. Nine sets of variable climate data are processed by the new model to produce an ensemble of potential economic prediction indicators. Analysis of gross domestic product and poverty rate reveal a significant overestimation of the country's future welfare by the mean climate model method, in comparison to probability density functions created from the variable climate ensemble. The ensemble is further utilized to demonstrate risk assessment capabilities. The addition of climate variability to the agro-economic model provides a framework, including realistic ranges of economic values, from which Ethiopian planners may make strategic decisions." Authors' abstractClimate variability, Water, Droughts, Flooding, Irrigation Economic aspects, Road construction Economic aspects, Investments, Economic situation, Agro-economic model,

THE VALUE OF THE HIGH ASWAN DAM TO THE EGYPTIAN ECONOMY

The High Aswan Dam converted a variable and uncertain flow of river water into a predictable and controllable flow. We use a computable general equilibrium model of the Egyptian economy to estimate the economic impact of the High Aswan Dam. We compare the 1997 economy as it was to the 1997 economy as it would have been for 72 historical, pre-dam water flows. The steady water flow increased transport productivity, while the seasonal shift in water supply allowed for a shift towards more valuable summer crops. These static effects are worth LE 4.9 billion. Investments in transport and agriculture increased as a consequence. Assuming that Egypt is a small open economy, this is worth another LE 1.1 billion. The risk premium on the reduced variability is estimated to be LE 1.1 billion for a modest risk aversion, and perhaps LE 4.4 billion for a high risk aversion. The total gain of LE 7.1 billion equals 2.7% of GDP.Egypt, High Aswan Dam, computable general equilibrium model, risk premium, water supply

Informed selection of future climates

Analysis of climate change is often computationally burdensome. Here, we present an approach for intelligently selecting a sample of climates from a population of 6800 climates designed to represent the full distribution of likely climate outcomes out to 2050 for the Zambeze River Valley. Philosophically, our approach draws upon information theory. Technically, our approach draws upon the numerical integration literature and recent applications of Gaussian quadrature sampling. In our approach, future climates in the Zambeze River Valley are summarized in 12 variables. Weighted Gaussian quadrature samples containing approximately 400 climates are then obtained using the information from these 12 variables. Specifically, the moments of the 12 summary variables in the samples, out to order three, are obliged to equal (or be close to) the moments of the population of 6800 climates. Runoff in the Zambeze River Valley is then estimated for 2026 to 2050 using the CliRun model for all 6800 climates. It is then straightforward to compare the properties of various subsamples. Based on a root of mean square error (RMSE) criteria, the Gaussian quadrature samples substantially outperform random samples of the same size in the prediction of annual average runoff from 2026 to 2050. Relative to random samples, Gaussian quadrature samples tend to perform best when climate change effects are stronger. We conclude that, when properly employed, Gaussian quadrature samples provide an efficient and tractable way to treat climate uncertainty in biophysical and economic models. This article is part of a Special Issue on “Climate Change and the Zambezi River Valley” edited by Finn Tarp, James Juana, and Philip War