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1. General observations Africa south of the Sahara is probably the most vulnerable region when it comes to the impact and consequences of climate changes. Yet the African continent runs a serious risk of being marginalized in the global dialogue on climate issues. Africa contributes little to the global emissions of CO2, and other greenhouse gases. The major focus of the Framework Convention on Climate Change is on abatement and mitigation of emissions rather than adaptation to the consequences of climate change, and African states have therefore been slow to ratify the treaty and not as active in the international negotiation process as states from other parts of the world. Curbing emissions if justifiably not a central African concern. Yet Africa's potential vulnerability should demand attention from both African policy makers and other decision makers. Africa's natural resource base is seriously threatened. The two central guiding principles of African climate policy both on the part of governments and of international institutions should be reducing vulnerability on the one hand and increasing resilience on the other. Decision makers should not use the remaining scientific uncertainty and the acknowledged dearth of detailed information on African resource management as an excuse for inaction. Not taking climate change into account could be a serious source of mismanagement and fallacious planning. Both increase in temperature and increasing variability of climate are serious dangers in the future. Land degradation policies as well as future energy development should be central concerns. Any strategy for Africa should seek to minimize the potential conflicts among the concerns and priorities for development, adaptation and abatement. Africa's vulnerability to climatic changes relates to a number of factors, including 1) the dependency on bio-fuel, 2) the importance of agriculture, 3) immobility, 4) poor health services, 5) population growth, and 6) low material standards. In the case of Africa, it is difficult to make clear distinctions between abatement and adaptation measures. Social and economic development are necessary in order to prepare the continent for adaptation. 2. African obligations and opportunities under the Climate Convention Forty-nine African states have signed the Climate Convention, but only 33 have ratified so far (23.06.95). Ratification is important because- 1) it signifies the acceptance of the principles of the convention and 2) ratification will be required for financial support under the FCCC. The substantive obligation of all African Parties is a commitment to formulate a climate policy and how it could be implemented. Developing countries shall report on their inventories of GHG emissions, along with their plans and measures to meet the convention's objective within three years after the entry into force of the convention. Least-developed countries may report at their own discretion. Multilateral financing institutions should invest in data gathering on all levels to enhance awareness and improve the possibility for responsible governance in respect to natural resource management and environmental protection. Joint Implementation (JI) can allow for cost effective implementation of the Climate Convention, and provide funding for climate related projects for countries where financial resources are scarce or lacking. 3. Modeling of climate change in Africa There are still substantial limitations in the ability to provide accurate predictions of future climate in Africa. Confidence in regional model predictions is low and there are substantial differences between the models. One can distinguish between three regions when it comes to climatic changes in Africa: 1) Sahel region, 2) corresponding dry regions south of the Equator in Zimbabwe, Botswana, Malawi, etc., and 3) the tropical region centered around the Equator. Major findings from IPCC -90 and -92 of relevance for Africa Temperature. Expected increases in annual average surface temperature at the time of C02 doubling: Northern subtropical region (including Sahel): 2 degrees Celsisus (0.5-3.0 degrees Celsisus), Tropical region: 1.5 degrees Celsisus (0.5-2.5 degrees Celsisus), and Southern subtropical region: 2 degrees Celsisus (0.5-3.0 degrees Celsisus). Precipitation: Increase in surface temperature and increased radiative cooling of the atmosphere due to doubling of CO2, concentrations lead to increased evaporation at the surface and increased intensity of convective precipitation (e.g. thunderstorms from large cumulus towers). Sea level rise: Thermal expansion is regarded as the most important process. Predictions are a 20±10cm increase in sea level at the time of CO2, doubling. IPCC-90 estimates up to a 65cm increase in sea level in year 2100, but this number is likely to be decreased to 40~45cm in the new IPCC-95 report. Observed trends. Since 1895, annual average temperatures has increased by 0.53'C over continental Africa. The recent 25 year dry period in Sahel is the most substantial change in observed precipitation in the global record. Explanations have been sought in 1) land use changes, and 2) circulation changes caused by changing patterns of sea surface temperatures (SST). If the drought represents the first sign of a global warming remains however uncertain. Current anthropogenic emissions of greenhouse gases (GHGS) in Africa. 1) Carbon dioxide (CO2): The major source is land use change (~70); the rest originates mainly from industry and transportation. The African contribution of CO2, was in 1990 estimated to be about 7 0f the world's total. 2) Methane (CH4,): Emissions in Africa are about 7 0f the world's total, with livestock being the main source. Industrial sources are oil and gas production and coal mining. 3) Nitrous oxide (N2O) sources are mainly of natural origin. 3) Chlorofluorocarbons (CFC): Africa's share of global CFC emissions is estimated at 3. 4. Natural resource management The uncertainties in predicting climate change impacts in Africa must be underlined, and other human or natural influences may mitigate or exacerbate the effects. Natural variability in Africa is also substantial, and people are to a large extent adapted to changes. Still, predicted human-induced climatic changes are expected to occur very rapidly, and little is known about the capability of the ecosystems - which forms the basis for human existence - to adapt to such changes. It is also clear that impacts of climate change will be unevenly distributed: groups with the highest present vulnerability, such as poor people and people living in marginal areas, will most likely suffer most. Generally, changes in the frequency of extreme weather events would probably have greater impact than changes in average conditions. Agricultural Resources. The fertilizing effect of enhanced CO2 level on plant growth is well documented in laboratory studies, but disputed when it comes to complex "real-world" systems. Other factors concerning climate change impacts on agriculture include 1) Warmer climate and changes in rainfall may reduce the appropriability of present crops. Already being a major problem today, loss of crop and livestock genetic resources may threaten sustainable agricultural development and adaptations to future changes. 2) Increased intensity of rainfall may increase soil erosion, nutrient leaching and crop damage, 3) Changes in timing and length of growing seasons may lead to planning problems, 4) Loss of rainfall in marginal and vulnerable areas would exacerbate drought and desiccation problems, increase risks for bushfire and put forests at their dry margins at risk, and increase problems in animal husbandry, 5) Some models predict a noticeable loss of food production in Africa, but regional variations would probably be large, and local differences (such as in cropping systems) will to a large extent determine how significant the climate change impacts will be. 6) Sea level rise will put low lying agricultural areas at risk, and may render major rivers unsuitable for irrigation. Fish resources. Fish make up a significant part of the food supply in Africa, with a total harvest potential estimated at 10.5 million tons. It is expected that global warming will, varying with species, relocate fish populations. Freshwater populations in small rivers and lakes are vulnerable due to restricted ability to move in response to changes. In areas becoming drier, loss of habitat would also represent a threat. Fish populations are generally very sensitive to even small changes in frequency of extreme events. For the more mobile marine fish populations, relocation does not necessarily mean that production and potential yields are lowered, but subsistence and small scale-fishermen may suffer if institutional arrangements do not enable them to move within regions and across boundaries. Biodiversity. Impacts on biological diversity should be of particular concern, as the welfare of human beings strongly depends on the existence of biological systems and processes. Biological diversity provides a wide range of goods and services, including a genetic basis for agricultural development, and represents a heritage of unique species and ecosystems. Species will probably respond differentially to climatic changes, leading to new aggregations and ecosystems. In ecological terms, the predicted changes will occur over a short period of time. Migration is expected to be the main adaptation strategy, and adaptation success will be determined by the species' ability to respond quickly enough, as well as the suitability of the migration routes: Migration may be blocked by natural or human imposed barriers, or the natural environment (e.g. soils) may be inappropriate. A large part of the natural bio-diversity in Africa is confined to isolated reserves surrounded by agricultural land. Small populations are particularly vulnerable, and endemic species will be at risk of extinction. The changes would on the other hand favor species with high dispersal rates, ability to colonize a wide range of habitats and a high tolerance towards stress. Water resources. Past droughts have shown that for marginal and vulnerable areas, even a small reduction in water supply is critical. Water scarcity has substantial health and ecological consequences. Even today, there is growing scarcity of water in many African regions, and several countries rely on water originating outside their borders. Sea level rises can be expected to lead to increased saltwater intrusion in the groundwater. Desalinization is too costly for most countries. Hydro power generation is also vulnerable to temperature increases and rainfall changes. Social, political and economic impacts. Many authors mention the risk of getting more "eco-refugees". In addition to the social and health problems they may create, major migrations would also increase political tensions. Economic impacts include costs of climate-caused damages and costs of adapting to climate changes. In low-lying areas, sea level rise may cause substantial losses of land for human habitation, which in river deltas and urban centers will be aggravated by subsidence caused by extraction of water and hydrocarbons. 5. African priorities African policy statements emphasize that contributions to Climate Change mitigation efforts should not adversely affect their development targets. Few African countries have national policies explicitly aimed at combating climate change impacts, as they are not required to develop such plans until 1997. African policies are expected to concentrate on combating vulnerability. More specifically, this involves capacity building in a number of areas, including formulation of national and regional inventories and programs, development of effective negotiation skills, developing research capabilities, conducting cost-benefit analyses, and capacity building in the area of technology assessment and transfer. Improvement in planning capacity and governance would improve Africa's resilience to eventual climate changes. Future energy scenarios. African countries should get support in taking advantage of new technology for alternative energy resources, where no-regret options should be given priority. It should be underlined that effective mitigation measures against global warming must reinforce national economic policies and enhance the welfare of households. Three different energy scenarios for Africa are discussed: 1) Stagnation, 2) Growth based on fossil fuels, and 3) Sustainable growth. Scenario 1 is characterized by slow economic development and rapid population growth. Scenarios 2 and 3 involve high social and economic development and falling fertility rates. Scenario 2 is a fossilfuels based development, while scenario 3 provides large scale use of alternative energy sources and sustainable economic development. Economic development and improved living standards, especially among women, are necessary to reduce population growth. Abatement measures. Abatement measures may be carried out as part of a development strategy. Such no-regret options may however need additional funding to be carried out, since market failures and national constraints to the economy may make such options too costly for African governments. One should focus on measures with limited impacts on activities "outside" the market economy. The concern for climate change could make the support of new technology in Africa more attractive, but one should be aware that this may bias the countries' preferences for projects.

This paper presents a summary of the work done within the European Union's Seventh Framework Programme project ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants). ECLIPSE had a unique systematic concept for designing a realistic and effective mitigation scenario for short-lived climate pollutants (SLCPs; methane, aerosols and ozone, and their precursor species) and quantifying its climate and air quality impacts, and this paper presents the results in the context of this overarching strategy. The first step in ECLIPSE was to create a new emission inventory based on current legislation (CLE) for the recent past and until 2050. Substantial progress compared to previous work was made by including previously unaccounted types of sources such as flaring of gas associated with oil production, and wick lamps. These emission data were used for present-day reference simulations with four advanced Earth system models (ESMs) and six chemistry transport models (CTMs). The model simulations were compared with a variety of ground-based and satellite observational data sets from Asia, Europe and the Arctic. It was found that the models still underestimate the measured seasonality of aerosols in the Arctic but to a lesser extent than in previous studies. Problems likely related to the emissions were identified for northern Russia and India, in particular. To estimate the climate impacts of SLCPs, ECLIPSE followed two paths of research: the first path calculated radiative forcing (RF) values for a large matrix of SLCP species emissions, for different seasons and regions independently. Based on these RF calculations, the Global Temperature change Potential metric for a time horizon of 20 years (GTP20) was calculated for each SLCP emission type. This climate metric was then used in an integrated assessment model to identify all emission mitigation measures with a beneficial air quality and short-term (20-year) climate impact. These measures together defined a SLCP mitigation (MIT) scenario. Compared to CLE, the MIT scenario would reduce global methane (CH4) and black carbon (BC) emissions by about 50 and 80%, respectively. For CH4, measures on shale gas production, waste management and coal mines were most important. For non-CH4 SLCPs, elimination of high-emitting vehicles and wick lamps, as well as reducing emissions from gas flaring, coal and biomass stoves, agricultural waste, solvents and diesel engines were most important. These measures lead to large reductions in calculated surface concentrations of ozone and particulate matter. We estimate that in the EU, the loss of statistical life expectancy due to air pollution was 7.5 months in 2010, which will be reduced to 5.2 months by 2030 in the CLE scenario. The MIT scenario would reduce this value by another 0.9 to 4.3 months. Substantially larger reductions due to the mitigation are found for China (1.8 months) and India (11–12 months). The climate metrics cannot fully quantify the climate response. Therefore, a second research path was taken. Transient climate ensemble simulations with the four ESMs were run for the CLE and MIT scenarios, to determine the climate impacts of the mitigation. In these simulations, the CLE scenario resulted in a surface temperature increase of 0.70 ± 0.14 K between the years 2006 and 2050. For the decade 2041–2050, the warming was reduced by 0.22 ± 0.07 K in the MIT scenario, and this result was in almost exact agreement with the response calculated based on the emission metrics (reduced warming of 0.22±0.09K). The metrics calculations suggest that non-CH4 SLCPs contribute ~ 22% to this response and CH4 78%. This could not be fully confirmed by the transient simulations, which attributed about 90% of the temperature response to CH4 reductions. Attribution of the observed temperature response to non-CH4 SLCP emission reductions and BC specifically is hampered in the transient simulations by small forcing and co-emitted spec