Ghana: Ecosystems

Climate change is anticipated to have a significant influence on the ecology and distribution of tropical ecosystems, though the magnitude, rate and direction of these changes are uncertain [29]. Under rising temperatures, increased frequency and intensity of droughts and shorter growing periods, wetlands and riverine systems become at risk of being converted to other ecosystems with plants being succeeded and animals losing habitats. Increased temperatures and droughts can also affect succession in forest systems while concurrently increasing the risk of invasive species, all of which affect the ecosystems. In addition to these climate drivers, reduced agricultural productivity and population growth might motivate further agricultural expansion resulting in increased deforestation, forest degradation and in return in increased forest fires, all of which will impact animal and plant biodiversity [30]. While ecosystems in the northern areas of Ghana are expected to be particularly affected given the higher expected temperature increase and mounting pressure from human land use, the challenges are prevalent throughout the entire country.

Species richness

Model projections of species richness (including amphibians, birds, and mammals) and tree cover for Ghana are shown in Figure 16 and 17, respectively. The volatility in species richness between 2030 and 2050 under RCP6.0 suggest a high sensitivity of species survival and population recovery to natural climate variability. Overall, however, model results indicate a slightly positive long-term impact of climate change on species richness under both RCPs (Figure 15), with the majority of models (at least 75 %) agreeing on this trend.

Figure 16: Projections of the aggregate number of amphibian, bird, and mammal species for Ghana for different GHG emissions scenarios.

Tree cover

With regards to tree cover shifts, model results are highly uncertain. Until mid-century, tree cover is projected to not change significantly in most parts of Ghana. Towards the end of the century, the average model projects slight decreases of tree cover under RCP2.6 and slight increases under RCP6.0, yet model agreement about these trends is low in most parts of the country (Figure 16).

Although these results paint an overall positive picture for climate change impacts on ecosystems and biodiversity, it is important to keep in mind that the model projections exclude any impacts on biodiversity loss from human activities such as land use, which have been responsible for significant losses of global biodiversity in the past, and are expected to remain the main driver of biodiversity loss in the future [31].

[28] T. M. Shanahan et al., “CO2 and fire influence tropical ecosystem stability in response to climate change,” Sci. Rep., vol. 6, no. 1, p. 29587, Jul. 2016.
[29] S. Agyemang, M. Muller, and V. R. Barnes, “Fire in Ghana’s dry forest: Causes, frequency, effects and management interventions,” in Proceedings of the large wildland fires conference, 2014, pp. 15–21.
[30] IPBES, “Global Assessment Report on Biodiversity and Ecosystem Services,” Bonn, 2019.