 Today I'm going to be talking about climate change in Africa, impact mitigation and adaption in the context of hydropower. My presentation has two parts. The first one is going to be on impact. I have selected three studies that I have had the opportunity to involve in the past through wider, and in different parts of Africa I have selected the three major basins on the Nile River Basin, on the Congo and Zambia River Basin. These studies are originally impact on the water resources, but I'll be focusing more on the hydropower aspect. The second part will be on the mitigation and adaption, and for this also I have selected two case studies. So I will not go into details of the methodology. These papers are published under wider working papers, so if more information is required you can always go to the website and get this information. But I'll give you a walk through the results that we managed to obtain. Just to give you a general background information regarding the current development of hydropower in Africa and the future potential, as you can see here on this map it shows the current hydropower capacity in Africa summarized by country. This data is adopted from the International Hydropower Association, a recently published report. It shows a total installed capacity currently with 35,000 megawatt. These numbers that you see on the maps are rankings. Currently Ethiopia standing first with a total installed capacity of 3,800 megawatt, followed by South Africa and Egypt. If you look at this chart at the bottom, it shows the trend in the past 10 years. There has been an increase of hydropower installed capacity by 40%, but particularly in the last three years, there has been an increase in the rate because countries are actively engaged in developing their hydropower resource. Both in order to meet the gap in electricity demand as well as to reduce the cost of electricity because at this point hydropower is still the cheapest form of energy in Africa. Therefore countries are engaged in developing their hydropower resources. Currently there are projects under construction with a total capacity of 17,000 megawatt. Countries have identified additional projects which are expected to come online in the next few decades with a total capacity of 77,000 megawatt. According to recent studies published, the total exploitable technical capacity is estimated at 1,800 terawatt per year. When we compare this value with what is being generated at the moment, currently about 7 to 8% of this potential has been tapped in Africa. Now the question is, knowing what we know about climate change, what does it mean to boast this existing hydropower energy as well as to the future potentials in Africa? I would like to highlight these two points regarding this interconnection of hydropower and climate change. As you may know hydropower is highly sensitive to climate change and it can be impacted both directly and indirectly directly because hydropower is dependent on hydrology and stream flow. Change in precipitation and temperature is going to bring change on stream flow both in terms of magnitude as well as variability. So this is going to change the energy generation. But indirectly, most water resource systems besides for power generation, they are also used for conceptive water use such as irrigation and municipal and industrial. So increase in temperature could result in increase in crop water requirement and therefore more abstraction from the river stream which gives less water for the hydropower. Even if that's not the case, in some instance it could change in the irrigation water requirement, could put a huge constraint in the way that we operate our hydropower system. So this will have an implication on the energy that we expect to get from these power systems. But on the other hand, hydropower is expected to play a major role in the climate adaption, which is primarily because the way hydropower is generated. It utilizes a natural water cycle therefore it's considered as a clean energy source although there are debates whether it's environmentally friendly or not. But in general it's a smokeless and it's a clean energy resource. Secondly, hydropower, especially hydropower facilities, especially with large dams, these reservoirs could also be used to manage the flood and drought that's expected to come as a result of this changing climate with more extreme events happening in our water resource system. Furthermore, hydropower by nature is a dispatchable energy source so as other renewable energy technologies grow and the energy mix continues to evolve there will be a need for energy storage and this dynamic capacity to balance the grid. So as hydropower has a good synergy with other renewable resources such as wind and solar its role is going to increase in the near future in terms of modulating this additional variability that we are going to introduce to our system when we incorporate more solar and wind power in our energy mix. So a little bit on the methodology, I will not get into details but so these are the three major basins that I'll be looking at. So we have the Nye River Basin, the Congo and the Zambia River Basin so we had a framework containing a sequence of water models. We had a hydrologic model that tried to see the, that translated these climate shocks in precipitation and temperature into what it means to the runoff. We had a crop model which is going to give us an estimate of this increase in the irrigation water requirement and we have a water resource model that puts together this and analyzes them and give us the expected energy system, energy generation from our hydropower schemes. So these sequence of models is driven by what is called a hybrid frequency distribution. It's a dataset produced at MITE. It's a probabilistic projection of climate variable, particularly precipitation and temperature which is formulated through the combination of MIT's IGSM and IPSS-AR4 models. It has a large set of scenarios so these are advantages in three aspects. One, it captures different uncertainties in the system such as the structure and uncertainty of the model and it also gives us, since we have enough number of scenarios we could be able to plot the project, the PDF and be able to see besides what happened to the median. We can also look at the extreme values and what happens to the tails of the distribution that you will see in the results. So I will start with Zambezi River Basin. Zambezi River Basin is on the southern and eastern part of Africa as you can see on that location map. We have some of the large hydropower facilities in that catchment, both existing in the future including Corbasa, Kariba and the Patoga Gorge development. It's a trans-boundary river. In terms of temperature and precipitation, you can see that on that side. We have two scenarios for this climate projection. One is an ensemble of scenarios for unconstrained emission which corresponds to business usually if we continue to release more greenhouse into the atmosphere. The other one is level one stabilization which is if we have some sort of policy of mitigation to limit our greenhouse emission and limit the concentration up to 560 parts per million. So these two curves that you see on the other side, the red dotted line and the blue correspond to this scenario. So for temperature, we're expecting to get a median increase of one degrees and up to 1.7 degrees for unconstrained emission. Regarding precipitation, the median of change is close to zero but we have extreme values in both direction expecting an increase or a decrease of 20% from the long-term average or from the base case for unconstrained emission and for level one stabilization, this could be reduced to plus or minus 10%. So what does this mean to the hydropower generation? So before going here, let me talk a little bit about variability. So even without climate change, there is a variability in the system which means we have different scale, we have seasonality if we are looking within a year but on a longer scale as well, we have inter-annual variability or we have large scale variability so the system has fluctuation by itself. So even without climate change, we could get a reduction or increase in hydropower generation by let's say our analysis year we're looking at 2045 to 2050 so that the green dotted line represents that. So even without climate change, we could expect a variability of minus 10 to plus 10 in the system. This is natural. But if we combine this natural variability with climate shock, the impact is going to be worse which is we could expect to minus 30 up to plus 10 and the median is going to be 10% of reduction in power generation from the base case. For level one stabilization, we can have the risk in general which means the extreme values will be reduced to 15% and the median is going to go down to minus 5% of reduction in power generation. This is a Nile River basin. Nile River basin is interesting in a way that it's highly hydrologically, it's a highly heterogeneous basin, it's the longest basin in Africa. So what was observed from this analysis that climate change has a differential impact which means it's showing more increase in runoff and more weight scenarios in the equatorial region in the southern part of the catchment close to Lake Victoria. However in the eastern part of the catchment, especially in the Blue Nile and the Takaziat Para, the Ethiopian highlands, it's showing drying as you can see here on this runoff plot. So we can see that the majority of the climate is showing a slight increase in the runoff. For Blue Nile, it's showing a reduction. So that chart that you see is a runoff at Aswan which is far downstream at that point just before it gets into Egypt. So we can see that the cumulative impact, the median is close to zero because of this canceling the southern catchment increase and the reduction from eastern basins cancels out and we're close to zero in terms of media but still the extreme values we could expect to minus 40 to 40 percent change in stream flow. So what does this mean to the hydropower generation? So this is summarized by country. If you look at Egypt, which is the far downstream country in the Nile basin, again like I indicated earlier, so this increase in the southern and the equator regions and the decrease in the Ethiopian highlands cancels out and brings the median close to zero. However we have higher risk. Like I said earlier, we could expect to minus 40 percent decrease in hydropower generation which is really significant as hydropower is one of the major sources of power. In Egypt we have the median shows slight decrease close to three percent. However again we have the tails of the distribution is large and we could expect reduction in power generation. However for equatorial regions such as Kenya and Uganda it shows increase up to even the median up to 15 percent of power generation. This for unconstrained emission and for level one stabilization I think it does not change in most of the cases, it moves the median a little bit but in terms of reducing the risk we can see that it's significant in all of the countries. In Congo river basin is central Africa where we find again the Inga dams. The Inga 3 dam was 4,800 megawatt installed capacity and the Grand Inga dam which is one of the plant projects. It's 40,000 megawatt which is expected to come hopefully in the next few years. So if we look at the impact on the energy generation both for the future in Grand Inga dam and for the existing for Congo again we're looking something similar to the Nile basin part of the Congo river basin shows reduction and half of the Congo river shows increasing and runoff. But overall the median does not have that much significant change in hydropower and the expected the tails are also within minus 5 and 5 percent. So also by nature it's the existing variability in the system is low. The flow in the river is pretty much consistent between years and even between seasons so that's why the Congo river basin is relatively resilient to the impact of climate change. So to summarize this, I think the first thing that we learn is climate change impact is highly dependent on the location. So that map there that's showing in the red area showing reduction in the runoff and the blue circle showing an increase. And again the southern is on basic catchment and part of the southern part of Congo shows some sort of reduction in runoff. So even if the median is not that much significant in some sense it makes adaption makes sense to mitigate or to reduce this extreme details of the probability just to be true in function. Now on to the second part of my presentation. This is on integration of hydropower with other renewable resources to make the penetration of renewable resource more useful in the system. So if you had the chance to participate in yesterday's renewable energy session you would see that there is a high potential of wind and solar power in South Africa. However there is a challenge that comes with integrating these resources into our energy mix. One of the challenges is intermittency. So there is a high fluctuation in the system even on hourly time step. Also these wind and solar are highly non dispatchable energy sources so we cannot easily control them as opposed to hydropower. So this is a typical power energy potential in South Africa. You can see that although the total capacity is really high there is a high intermittency in the system. If you plot the power duration curve you can see that the 90s of percentile dependable energy is really low up to 1000 megawatt. However there is opportunities in the region which is one there is an opportunity for storage in the Zambezi river basin. So what this study trying to look at was trying to see this coordinated operation of wind, solar and hydropower dams in Zambezi to see if we can have higher penetration of wind and solar in the system. So the analysis indicates that a coordinated operation is both wind and solar for South Africa as well as for the countries in Zambezi. So if you look at this distribution the duration curve was really low for the 90 percentile is now 50 percent. So that's an increase in by 20 percent of penetration into the power mix. It's not only advantages for the South Africa but in terms of making the Zambezi system more reliable which means originally the countries in Zambezi used to have an unmade demand in their power system. Now the system is more reliable and we have reduced number of unmade demand. The fifth paper is on regional power interconnection or powerful interconnection from climate adaption perspective. So papers have indicated from climate change perspective adopting regional approach to infrastructure development rather than the national one is posed to yield a better result in terms of making the system more resilient. So this research was trying to look at what will happen to the variability that as a result of climate change whether we are going to have the systems coming in sync or off sync say by 2050 or by 2100. So the results show that this blue the color indicate so the pattern of variability in which they are going to shift by 2050. So the blue Nile the eastern Nile system including the Equatoria region will be in sync with the western part of Africa. However the central and the it's going to be off sync with the central part Congo river basin and the Zambezi river basin and in general the southern part of Africa. So if we interconnect these power pools in the future the system is going to be more resilient because when we have drying let's say in Blue Nile basin the system in southern Africa or in the southern power pool is going to be an increase. So this was what this research was trying to look at. Some concluding remarks in terms of impact there's no single direction and it varies by location and climate change combined with variability which is often overseen is also important in terms of evaluating what our change in energy generation is going to be by the end of 2050 or 200. Also adaption makes sense in the context of risk and also this idea of synergy of renewable resource with hydropower. Integrated operation should be considered when when planning a new hydropower to accommodate this coordinated operation. Also this regional interconnection is a tool for better resilient system. So there should be consideration for strong regional cooperation to achieve regional goal as well as the wind wind solution in terms of adapting to climate change. Thank you. Thank you very much. Johannes. So we have time for two questions down in the front. Thank you Johannes for the presentation. Khalid from Humboldt University of Berlin and Khotum University in Sudan. Our recent research and observation at least in the eastern Nile basin show that climate variability is very important even more than the climate change taken by the mean temperature and rainfall changes. And this is confirmed by some of your graphs showing that natural variability in the flow of water is very significant. I'm interested in knowing how do you account for climate variability within your climate change scenarios and what do you think about you know addressing this in a more sophisticated way. Thank you. I don't know if you know but there's a lot of controversy for the dams. So are these cattle running off the river dams or reservoir dams? Both of them have a lot of environmental and social and human rights problems also because the reservoirs they emit also methane which is much more powerful than CO2 in climate kind of things because they decompose the vegetation, the trees and shrubs and what are the reservoirs. And also they're on the river they kill off the migratory fishes because people lose their livelihoods and like that. So could you give an example how you mitigate these problems which are very very big problems with the hydropower and it's not no way clean it's renewable but no clean. My question concerns the impact of hydropower generation in connection with Lake Turkana in northern Kenya. As I understand the Ethiopians are building a dam on the river that supplies that water to Lake Turkana and now there's a dispute brewing between Kenya and Ethiopia because already there is a shortage of water in the shallow parts of Lake Turkana which are needed for the fish to regenerate and for migrating birds to stop over and even live there, reside there. And so there's a very serious impact eventually on the populations living around Lake Turkana because they depend on fish for their protein supply. And in spite of what requests to the government of Ethiopia to mitigate these problems the mass media says that the Ethiopians have just ignored the Kenya concerning this matter. I'd like to know your opinion about this. Okay so we're going to ask Johannes to answer the climate change related questions. There are two very other loaded questions which if we can get to later about the role of hydropower and environmental impacts and as an Ethiopian he'll be ready to answer about that. So if you could answer the climate variability and then we'll go back to that. I think I'll address the variability question which is it's true. Yeah the Nile especially the blue Nile basin is highly variable both within short scale as well as long term long scale. So this is accounted in the modeling through incorporating these creating hybrid scenarios which means a combination of this variability, different variability and a combination of climate shocks. So we have what's called if you've seen the presentation we have a third, the red probability distribution function which also accounts this variability into the system. So yes it's really important to take variability into consideration and in the case of blue Nile yes the dominant is more variability than the change in climate shocks. Do you want to say anything about Gibe? Well yeah yes I guess there are the two questions on the social and environmental impact of dam. Yes that's true especially if it's large reservoir it's going to change the system and it's definitely going to have a social both environmental consequences but currently Ethiopia the priority is fulfilling the energy demand so the country is giving more priority for developing large scale hydropower development but still the controversy is there whether it's in the long run it's advantages to the country or not but at this point it makes economical sense that's why the country is actively engaged in developing Gibe 1, Gibe 2, Gibe 3 these are cascade dams on the lake Turkana so yes I think this is as far as I can go at this point.