Achieving food security goals in West Africa will depend on the capacity of the agricultural sector to feed the rapidly growing population and to moderate the adverse impacts of climate change. A number of studies anticipate a reduction of the crop yield of the main staple food crops in the region by 2050 due to global warming. However, it is likely that this crop yield reduction has already started a few decades ago. Indeed, a recent study, within the AMMA-2050 project, found that crop production might have already been affected by human-induced climate change, with significant yield losses estimated in the historical past.
This study used a large ensemble of 200 historical climate simulations derived from an atmospheric general circulation model and two process-based crop models to evaluate the effects of historical climate change on crop production of sorghum and millet in West Africa. Half of the simulations is based on a realistic simulation of the actual climate, while the other is based on a climate simulation that does not account for human influences on climate systems (that is, the non-warming counterfactual climate condition).
The results show that the last simulated decade, 2000-2009, is approximately 1°C warmer in West Africa in the ensemble accounting for human influences on climate, with more frequent heat and rainfall extremes. These altered climate conditions have led to regional average yield reductions of 10-20% for millet and 5-15% for sorghum in the two crop models. The economic impact might have been very important. Indeed, the average annual production losses across West Africa in 2000–2009 associated with historical climate change, relative to a non-warming counterfactual condition (that is, pre-industrial climate), was estimated to be 2.33–4.02 billion USD for millet and 0.73–2.17 billion USD for sorghum. The estimates of production losses can be a basis for the loss and damage associated with climate change to date and useful in estimating the costs of the adaptation of crop production systems in the region.
Read more and download the paper “Evidence of crop production losses in West Africa due to historical global warming in two crop models” here.
The work reported on in this story is part of the AMMA-2050 (African Monsoon Multi-disciplinary Analysis 2050) research project, which aims to address the challenges of understanding how the monsoon will change in future decades, to 2050, and how this information can be most effectively used to support climate-compatible development in the region of West Africa.
This article was written by AMMA-2050 researcher Benjamin Sultan.