## 5 Results  
In Figure 4 the trends for the three chosen periods are presented. For the years 1902-1957 no clear trend can be seen from the linear regression analysis. For the years 1957-2012, a small increase in temperature can be detected. For the years 1973-2012, a significant temperature increase is present. Figure 4 shows that the average temperature during the rainy season for the first 10 years, 1974-1984, was 25.4 \({}^{\circ}\)C, while it increased to 26.3 \({}^{\circ}\)C during the last 10 years, 2002-2012. The temperature gradientwas +0.9 \({}^{\circ}\)C during this period. There is clear statistical data for a positive temperature trend during the last four decades from 1973 to 2012. The positive trend in Figure 4 and in Table 1 show the historically recorded trend for the rainy season of October to March, which provides evidence for an approximately 3.6 \({}^{\circ}\)C increase in temperature that can be expected to occur up to the year 2100 according to Figure 5, the rainy season thus becoming hotter than it is today. The third period, that of 1974-2012, indicates an increase in both the observed temperature, along with the projected temperature, pointing to a situation of a continuing rise in temperature. These observations thus provide evidence for continuing climate change, with both the temperature and the evaporation of water increasing and the availability of water then decreasing; this very much presents a challenge to the hoped-for success of the hydropower project. There is uncertainty, however, regarding a decrease in precipitation, since the precipitation shows no significant trend in terms of results of the simulations, yet USAID and UNDP have studied this to some extent and have found that precipitation can be expected to increase in the country as whole. For precipitation for October to March, there is no significant trend visible for the dataset. Climate change scenarios do suggest an increase in precipitation due to warmer climate, yet with a faster increase in temperature, the evapotranspiration will grow faster than the precipitation. Extrapolating data from Figure 5 indicates an increase in temperature of 3.6 \({}^{\circ}\)C in 2100, as presented in Table 1. The rainy season will become warmer and most probably shorter in the future. Comparing the data set for 1974-2012 with the projected temperatures in Table 1 and Figure 6 suggests that the observed temperatures have increased even faster than the projected ones. An interpretation is that climate change is already visible in Mozambique. The evaporation will continue to reduce the available water in the river basins and alter the runoff for the hydropower plants. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Current** & **Annual** & **Annual** & **2100 Projected** & **2100 Projected** \\  & **Average (\({}^{\circ}\)C)** & **Trend 1 (\({}^{\circ}\)C/y)** & **Trend 2 (\({}^{\circ}\)C/y)** & **Average 1 (\({}^{\circ}\)C)** & **Average 2 (\({}^{\circ}\)C)** \\ \hline October & 25.78 & 0.009 & 0.029 & 26.56 & 28.34 \\ November & 26.68 & 0.016 & 0.024 & 28.07 & 28.83 \\ December & 26.53 & 0.016 & 0.023 & 27.97 & 28.56 \\ January & 26.42 & 0.015 & 0.013 & 27.76 & 27.53 \\ February & 26.40 & 0.013 & 0.016 & 27.53 & 27.82 \\ March & 25.91 & 0.015 & 0.019 & 27.27 & 27.58 \\ \hline \hline \end{tabular} \({}^{1}\) Liner trend from 1956–2012. \({}^{2}\) Liner trend from 1973–2012.  
\end{table} 
Table 1: Trends and Projections of Monthly Average Temperatures for Rainy Season. Figure 5: Trends in average temperature for October to March in the Ara-Centro region. Extrapolating the results from Table 1 to the effects on precipitation in Mozambique, it is possible to calculate how the rainfall pattern will change until 2100.