Category: Climate risk profile

Burkina Faso: Climate

Temperature

Figure 2: Air temperature projections for Burkina Faso for different GHG emissions scenarios.4

In response to increasing greenhouse gas (GHG) concentrations, air temperature over Burkina Faso is projected to rise by 1.9 to 4.2 °C (very likely range) by 2080 relative to the year 1876, depending on the future GHG emissions scenario (Figure 2). Compared to pre-industrial levels, median climate model temperature increases over Burkina Faso amount to approximately 2.0 °C in 2030, 2.3 °C in 2050 and 2.4 °C in 2080 under the low emissions scenario RCP2.6. Under the medium / high emissions scenario RCP6.0, median climate model temperature increases amount to 2.0 °C in 2030, 2.6 °C in 2050 and 3.6 °C in 2080.

Very hot days

Figure 3: Projections of the annual number of very hot days (daily maximum temperature above 35 °C) for Burkina Faso for different GHG emissions scenarios.

In line with rising mean annual temperatures, the annual number of very hot days (days with daily maximum temperature above 35 °C) is projected to rise dramatically and with high certainty all over Burkina Faso (Figure 3). Under the medium / high emissions scenario RCP6.0, the multi-model median, averaged over the whole country, projects 32 more very hot days per year in 2030 than in 2000, 52 more in 2050 and 88 more in 2080. In some parts, especially in south-western Burkina Faso, this amounts to about 250 days per year by 2080.

Precipitation

Figure 4: Annual mean precipitation projections for Burkina Faso for different GHG emissions scenarios, relative to the year 2000.

Future projections of precipitation are less certain than projections of temperature change due to high natural year-to-year variability (Figure 4). Out of the four climate models underlying this analysis, two models project a decreasing trend in mean annual precipitation over Burkina Faso, while the other two models project an increase. Median model projections show strong interannual variability but no clear trend in mean annual precipitation until 2080 under either RCP.

Heavy precipitation events

Figure 5: Projections of the number of days with heavy precipitation over Burkina Faso for different GHG emissions scenarios, relative to the year 2000.

In response to global warming, heavy precipitation events are expected to become more intense in many parts of the world due to the increased water vapour holding capacity of a warmer atmosphere. At the same time, the number of days with heavy precipitation events is expected to increase. However, this tendency can only be found in half of the climate projections for Burkina Faso. Median climate model projections show no change in the number of days with heavy precipitation under either RCP (Figure 5). The year 2080 is projected to receive 8 days of heavy precipitation, which is equal to the year 2000.

Soil moisture

Figure 6: Soil moisture projections for Burkina Faso for different GHG emissions scenarios, relative to the year 2000.

Soil moisture is an important indicator for drought conditions. In addition to soil parameters and management, it depends on both precipitation and evapotranspiration and therefore also on temperature, as higher temperatures translate to higher potential evapotranspiration. Annual mean top 1-m soil moisture projections for Burkina Faso show a decrease of 2.5 % for both RCP2.6 and RCP6.0 by 2080 compared to the year 2000 (Figure 6). However, there is considerable modelling uncertainty as different hydrological models project different directions of change, which makes it difficult to identify a clear trend.

Potential evapotranspiration

Figure 7: Potential evapotranspiration projections for Burkina Faso for different GHG emissions scenarios, relative to the year 2000.

Potential evapotranspiration is the amount of water that would be evaporated and transpired if sufficient water was available at and below the land surface. Since warmer air can hold more water vapour, it is expected that global warming will increase potential evapotranspiration in most regions of the world. In line with this expectation, hydrological projections for Burkina Faso indicate a stronger rise of potential evapotranspiration under RCP6.0 than under RCP2.6 (Figure 7). Under RCP6.0, potential evapotranspiration is projected to increase by 2.7 % in 2030, 3.8 % in 2050 and 6.8 % in 2080 compared to year 2000 levels.

4 Changes are expressed relative to year 1876 temperature levels using the multi-model median temperature change from 1876 to 2000 as a proxy for the observed historical warming over that time period.

Ethiopia: Climate

Temperature

Figure 2: Air temperature projections for Ethiopia for different GHG emissions scenarios.5

In response to increasing greenhouse gas (GHG) concentrations, air temperature over Ethiopia is projected to rise by 1.6 to 3.7 °C (very likely range) by 2080 relative to the year 1876, depending on the future GHG emissions scenario (Figure 2). Compared to pre-industrial levels, median climate model temperature increases over Ethiopia amount to approximately 1.5 °C in 2030, 1.8 °C in 2050 and 1.8 °C in 2080 under the low emissions scenario RCP2.6. Under the medium / high emissions scenario RCP6.0, median climate model temperature increases amount to 1.5 °C in 2030, 1.8 °C in 2050 and 2.4 °C in 2080.

Very hot days

Figure 3: Projections of the annual number of very hot days (daily maximum temperature above 35 °C) for Ethiopia for different GHG emissions scenarios.

In line with rising mean annual temperatures, the annual number of very hot days (days with daily maximum temperature above 35 °C) is projected to rise substantially and with high certainty, in particular over eastern Ethiopia (Figure 3). Under the medium / high emissions scenario RCP6.0, on average over all Ethiopia, the multi-model median projects 18 more very hot days per year in 2030 than in 2000, 26 more in 2050 and 50 more in 2080. In some parts, especially in eastern Ethiopia, this amounts to about 200 days per year by 2080.

Precipitation

Figure 4: Annual mean precipitation projections for Ethiopia for different GHG emissions scenarios, relative to the year 2000.

Future projections of precipitation are less certain than projections of temperature change due to high natural year-to-year variability (Figure 4). Out of the three climate models underlying this analysis, one model projects almost no change in mean annual precipitation over Ethiopia, while the other two models project an increase. Median model projections for RCP2.6 show almost no change in total precipitation per year until 2080, while median model projections for RCP6.0 show a precipitation increase of 85 mm / year by 2080 compared to year 2000.

Heavy precipitation events

Figure 5: Projections of the number of days with heavy precipitation over Ethiopia for different GHG emissions scenarios.

In response to global warming, extreme precipitation events are expected to become more intense in many parts of the world due to the increased water vapour holding capacity of a warmer atmosphere. At the same time, the number of days with heavy precipitation events is expected to increase. This tendency is also found in climate projections for Ethiopia (Figure 5), with climate models projecting a slight increase in the number of days with heavy precipitation events, from 7 days / year in 2000 to 8 days / year in 2080 under RCP2.6 and 9 days / year under RCP6.0 by 2080.

Soil moisture

Figure 6: Soil moisture projections for Ethiopia for different GHG emissions scenarios, relative to the year 2000.

Soil moisture is an important indicator for drought conditions. In addition to soil parameters, it depends on both precipitation and evapotranspiration and therefore also on temperature as higher temperatures translate to higher potential evapotranspiration. Annual mean top 1-m soil moisture projections for Ethiopia show almost no change to a slight decrease for RCP2.6, while under RCP6.0, soil moisture is projected to slightly increase approaching a 1 % change by 2080 compared to the year 2000 (Figure 6). However, looking at the different models underlying this analysis, there is large year-to-year variability and modelling uncertainty, which makes it difficult to identify a clear trend.

Potential evapotranspiration

Figure 7: Potential evapotranspiration projections for Ethiopia for different GHG emissions scenarios, relative to the year 2000.

Potential evapotranspiration is the amount of water that would be evaporated and transpired if sufficient water were available at and below land surface. Since warmer air can hold more water vapour, it is expected that global warming will increase potential evapotranspiration in most regions of the world. In line with this expectation, hydrology projections for Ethiopia indicate a stronger and more continuous rise of potential evapotranspiration under RCP6.0 than under RCP2.6 (Figure 7). Under RCP6.0, potential evapotranspiration is projected to increase by 2.0 % in 2030, 2.7 % in 2050 and 4.4 % in 2080 compared to year 2000 levels.

5 Changes are expressed relative to year 1876 temperature levels using the multi-model median temperature change from 1876 to 2000 as a proxy for the observed historical warming over that time period.

Ghana: Climate

Temperature

Figure 2: Air temperature projections for Ghana for different GHG emissions scenarios, relative to the year 1876.

In response to increasing greenhouse gas (GHG) concentrations, air temperature over Ghana is projected to rise by 0.7 – 2.7°C (very likely range) by 2080 relative to year 2000, depending on the future GHG emissions scenario. Compared to 2000 levels, median climate model temperature increases over Ghana amount to approximately 0.8°C in 2030, 1.1°C in 2050, and 1.2°C in 2080 under the low emissions scenario RCP2.6. Under the medium/high emissions scenario RCP6.0, median climate model temperature increases amount to 1.0°C in 2030, 1.5°C in 2050, and 2.3°C in 2080.

Very hot days

Figure 3: Projections of the annual number of very hot days (daily maximum temperature greater than 35 °C) for Ghana for different GHG emissions scenarios.

In line with rising annual mean temperatures, the annual number of very hot days (days with daily maximum temperature greater than 35°C) is projected to rise substantially in particular over northern Ghana. Under the medium/high emission scenario RCP6.0, on average over all of Ghana, the median climate model projects 34 more very hot days per year in 2030 than in 2000, 55 more in 2050, and 94 more in 2080. In some parts, especially in the North of Ghana, this amounts to about 300 days per year by 2080.

Sea level rise

Figure 4: Sea level rise projections for the coast of Ghana for different GHG emissions scenarios, relative to the year 2000.

In response to globally increasing temperatures, the sea level off the coast of Ghana is projected to rise. Until 2050, very similar sea levels are projected under different GHG emissions scenarios. Under RCP6.0 and compared to year 2000 levels, the median climate model projects a sea level rise by 11 cm in 2030, 20 cm in 2050, and 39 cm in 2080. This threatens Ghana’s coastal communities and may cause saline intrusion in coastal waterways and groundwater reserves.

Precipitation

Figure 5: Annual mean precipitation projections for Ghana for different GHG emissions scenarios, relative to the year 2000.

Future projections of precipitation are substantially more uncertain than projections of temperature or sea level rise. Detecting trends in annual mean precipitation projections is complicated by large natural variability at multi-decadal time scales and considerable modelling uncertainty (Figure 5). Of the four climate models underlying this analysis, one projects a decline in annual mean precipitation over Ghana. According to the other three models, there will be no change. Therefore, our best estimate is that there will be almost no change in total precipitation per year until 2080 irrespective of the emissions scenario, yet this result is highly uncertain.

Heavy precipitation events

Figure 6: Projections of the number of days with heavy precipitation over Ghana for different GHG emissions scenarios.

In response to global warming, extreme precipitation events are expected to become more intense in many parts of the world due to the increased water vapor holding capacity of a warmer atmosphere. At the same time, the number of days with heavy precipitation is expected to increase. This tendency is also found in climate projections for Ghana, with climate models projecting a slight increase in the number of days with heavy precipitation events, from 7 days/year in 2000 to 8 days/year under RCP2.6 or 9 days/year under RCP6.0 by 2080. Central Ghana is subject to increased heavy precipitation, while for the far north, no change is projected by the multi-model mean.

Soil moisture

Figure 7: Soil moisture projections for Ghana for different GHG emissions scenarios, relative to the year 2000.

Soil moisture is an important indicator for drought conditions. In addition to soil parameters, it depends on both precipitation and evapotranspiration and therefore also on temperature as higher temperature translates to higher potential evapotranspiration. Annual mean top 1-m soil moisture projections for Ghana show a decreasing tendency. This tendency is stronger than the corresponding precipitation change projections, which reflects the influence of temperature rise on evapotranspiration.

Potential evapotranspiration

Figure 8: Potential evapotranspiration projections for Ghana for different GHG emissions scenarios, relative to the year 2000.

Potential evapotranspiration is the amount of water that would be evaporated and transpired if there were sufficient water available at and below the land surface. Since warmer air can hold more water vapor, it is expected that global warming will increase potential evapotranspiration in most regions of the world. In line with this expectation, hydrology projections for Ghana indicate a stronger rise of potential evapotranspiration under RCP6.0 than under RCP2.6. Specifically, under RCP6.0, compared to year 2000 levels, potential evapotranspiration is projected to increase by 3.2% in 2030, 4.6% in 2050, and 7.4% in 2080.