Biophysical Results

EPIC simulations show that sorghum was the most susceptible crop to the projected climate change, as its yields decreased significantly, while groundnuts and cowpeas were relatively less susceptible. Cotton yields increased in most cases, while millet was largely unaffected. Results showed that relatively humid areas of Mali would be less affected by climate change compared to drier areas. Table 29.3 shows nationally averaged changes in crop yields under the projected climate change.

Under the HadCM scenario, 33 of the 48 crop-region cases show yield losses. In drier and less productive regions

Table 29.3 Nationally Area

Weighted Averages for Percentage

Changes in Crop Yields Under Projected Climate Conditions

Global Circulation Models

Crop HadCM CGCM

Cotton

Cowpeas

Groundnuts

Maize Millet

8.47

Sorghum

Notes: Estimated with erosion-productivity impact calculator (EPIC) model. CGCM = Canadian coupled general circulation model; HadCM = Hadley Center coupled model.

of Mali, sorghum yield decreased up to 18%, while in subhumid areas of Sikasso, projected sorghum yield decreases were modest (5% to 7%). Cowpeas were only somewhat affected, showing decreases in the range of 1% to 6%.

Losses in yields are higher under CGCM projected climate change than under HadCM. CGCM exhibited lower yields in 42 of the 48 cases. Yield increases were found in only 11 cases, compared to 15 under the HadCM simulations. High losses were found for sorghum, with yield decreases up to 30% in Segou and Koulikoro.

Livestock impacts resulted from changes in forage yield (Table 29.4) and livestock performance (Table 29.5). Forage yields are projected to decrease between 5% to 36%. The primary reason is the combined loss of grass basal area due to overgrazing and reduced woody plant cover, coupled with increased temperatures during the growing season. The results show small ruminants to be more resilient to climate change compared to cattle.

Rate of degradation in cropland productivity was estimated using EPIC. The rate of degradation, in terms of yield losses varied between 19% to 25%, compared to the base

Table 29.4 Percentage Changes in Forage Yields Under Projected Climate in Sikasso Region

Global Circulation Models Region HadCM CGCM

Central -5 -12

Notes: Estimated with Phygrow plant growth (PHYGROW) model. CGCM = coupled general circulation model; HadCM = Hadley coupled model.

Table 29.5 Changes in Animal Intake and Rate of Weight Gain (Estimated From NUTBAL Model)

Animal HadCM CGCM HadCM CGCM

Cattle -12.8 -13.3 -13.6 -15.7 Sheep -3.4 -5.9 0.0 0.0 Goats -4.1 -4.7 0.0 0.0

Notes: Estimated with nutritional balance (NUTBAL) model. CGCM = Canadian coupled general circulation model; HadCM = Hadley Center coupled model.

conditions for the three subregions in Sikasso by 2030 (Table 29.6).

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