Despite many international and local initiatives on disaster risk management and advances in scientific knowledge, the social and economic impact of natural disasters in emerging economies and developing countries is growing. This is due to the fact that their fragile economies are unable to absorb the shocks caused by natural disasters combined with the increasing vulnerability of the exposed population aggravated by the rapid growth of urban population, weak institutions and rampant conflicts. Most of these countries are currently struggling to implement an effective risk reduction strategy.
Climate change is likely to rapidly exacerbate this situation. Climate change threatens the cities and fast urbanising coasts where about 38 per cent of Africa’s population lives, that is to say 297 million people live in urban areas. By 2030, this is expected to grow to approximately 54 per cent of Africa's projected population of around 1405 million. Africa's rate of urbanization of 3.5 per cent per year is the highest in the world, resulting in more urban areas with large population, as well as in the expansion of existing urban areas. There are currently forty cities in Africa with populations of more than a million and it is expected that by 2015 seventy cities will have populations of one million or more. In many urban areas rates of economic growth and infrastructure development have lagged urbanization rates, resulting in high levels of unemployment, inadequate standards of housing and services, and impacts on human health and development. Environmental disasters and conflicts have also caused many people to flee rural areas and to seek refuge in urban centres. Weather-related disasters are doing increasing damage to water supply already scarce in many places, and other critical infrastructure such as energy, transport, and telecommunications may become more vulnerable to climate change related risks. These add to African cities' significant sustainability challenges, including urban sprawl, population growth, pollution and the loss of biodiversity. The vulnerability of African cities is considered to be influenced not only by changing biophysical conditions, but also by dynamic social, economic, political, institutional and technological structures and processes. Thus, the planners, managers and researchers within African cities need reliable forecasts of the local impact of climate change and need to be better equipped to strengthen the coping capacities of urban communities. The subsequent extension of knowledge of the direct and indirect impacts of climate change and the spatial and temporal scales over which they are felt will ultimately benefit urban communities more widely, both within and beyond the developing world.
Why the CLUVA project
Although Africa is considered a continent particularly vulnerable to the effects of climate change, its real impact, particularly on a local scale, is still poorly understood. Prediction of climate change impacts in Africa in the 21st Century are in fact based on Global Circulation models with low resolution and a very broad scale which fail to represent two potentially important drivers of African climate variability, namely the El Niño/Southern Oscillation and land cover change. The task of developing reliable predictions of future climate change in Africa is further complicated by the lack of accurate baseline data on current climate and by the intricacies of climate space and time variations.