Climate resilient crops in hot-spot regions of climate change: the case of quinoa in Burkina Faso

Since the industrial revolution, there has been a continuous increase in atmospheric carbon dioxide (CO2) concentrations to the highest levels in the last 800,000 years, over 400 ppm. This underscores human-induced climate change, and CO2-projections are not promising (Representative Concentration Pathway (RCP) 4.5: 550 ppm of CO2; RCP 8.5: 1000 ppm of CO2 by 2100). Scientists foresee a point of no return in the climate system, where humankind and ecosystems are expected to face unprecedented changes in climate. Populations living in less developed countries are likely to suffer the most severe impacts of climate change (heatwaves, droughts, flooding…). With uncontrollable population growth, high-reliance on climate-sensitive sectors (agriculture), lack of governance, poor educational and health systems, and conflict, a sophisticated time-bomb is developing. The time-bomb will be in the form of populations facing starvation, causing conflict and displacing, even more, the population within and from the Sahel. The Sahel is often portrayed as one of the world’s most vulnerable regions to climate change impacts, which are expected to severely affect Sub-Saharan agriculture and consequently human livelihoods. Many of the crops (maize, sorghum, millet, sugarcane, fonio and tef) grown at lower latitudes, have a C4 photosynthetic pathways which are more efficient in environments with higher solar radiation when compared to C3 crops. Nevertheless, C3 crops have a photosynthetic pathway that benefit more from increasing CO2 concentrations in the atmosphere. This is because the optimal CO2 atmospheric concentrations for enhancing the photosynthetic rate of C3 crops has not yet been reached. Modelling of C4 crops under changing climatic conditions has shown considerable yield losses of main crops (maize, millet and sorghum) within the region and for the coming decades. Trait improvement of C4 crops is time consuming with limited time for action, therefore alternative strategies to adapt to future climate are now imperative. Different agricultural adaptive strategies may be available for the Sahel to face the detrimental impacts of climate change. Hence this research proposes a novel approach: to introduce a resistant to abiotic-stresses-C3-crop in a country suffering from high undernourishment rates, Burkina Faso. Field experimentation with Chenopodium quinoa Willd. has shown that quinoa is a very resilient plant, that can cope with drought-stress conditions (200-400 mm) and withstand the effect of heat-stress (38 °C), besides having low nitrogen nutrient requirements (25 kg N ha-1). Multimodel simulations under different climate scenarios (RCP 4.5 and RCP 8.5), predicting temperature increases of 2 °C to 5 °C, have shown that quinoa is capable of adjusting, with even yield enhancements, to the projected temperatures and CO2 concentrations. Although crop substitution may face social and research challenges, it is a more rapid solution for building climate-resilient communities than crop improvement.