Of all the places on Earth, the African continent—and its societies, ecosystems, and agricultural systems—is one of the most vulnerable to the effects of climate change. Despite the urgent need to assess the effects of Africa’s changing climate, current climate predictions for Africa contain some of the largest uncertainties. To address this need, a community of scientists from around the world is making rapid advances in a wide range of environmental sciences.
As part of this international effort, 80 participants attended the first workshop on Climate Change in Africa (CCA 2017), sponsored by Past Global Changes (PAGES). Scientists from 20 countries attended; among them were scientists from the African countries of Tunisia, Algeria, Morocco, Benin, Congo, Cameroon, Senegal, and South Africa. CCA 2017 was a great opportunity for all participants to present their work and discuss the mechanisms of climate changes in Africa and how the global hydrological cycle, oceanic and atmospheric circulation, and marine and terrestrial ecosystems respond.
The topics of the workshop covered a broad range of disciplines, including proxy-based climate reconstructions, model simulations, past climate forcing mechanisms, regional climate dynamics, and the influence of climate on human populations. Keynote speakers introduced five major topics; presenters then discussed these topics through oral and poster presentations:
- mechanisms of African climate change
- effects on ecosystems and agrosystems
- the African monsoon
- the Mediterranean region
- land-ocean interactions
The presentations and discussions highlighted the scarcity of long-term climate reconstructions required to compare the current climate conditions in Africa with preindustrial climate and to evaluate anthropogenic effects. For example, the recent recovery of Sahel rainfall levels from previous drought conditions has been interpreted as the result of greenhouse warming. However, this recovery may not appear as a significant short-term decadal event when it is considered in a context that spans several centuries. This longer context shows that the Sahel is currently experiencing its worst drought in the past 1,600 years.
Long climate reconstructions support climate models that predict an increasing drought in the Sahel with future global warming. The Mediterranean region is also among the regions identified for a high risk of future drought. Workshop participants stressed the potential dramatic effects that such climate degradations would have for food production and political stability in Africa.
Workshop presenters also stressed that a variety of sources, including cloud parameterization and systematic biases in climate simulations, continue to produce large uncertainties in future rainfall predictions for all of tropical Africa. One particular source of uncertainty is the incorrect representation of sea surface temperature gradients in the equatorial Atlantic. In addition, population growth has increasingly degraded the vegetation cover, increasing drought conditions by diminishing water recycling and increasing surface runoff and floods during rainfall events. The conference delegates strongly recommend increased national and international investments in field climate observations and related ecological consequences.
It was very apparent that there are extremely few African climate change scientists and that they face a terrible lack of support in regard to the urgency and importance of their mission. Increasing African countries’ resilience to climate change will require a significant effort at the national and international levels to train and attract qualified scientists in Africa.
A follow-up meeting is planned for 2019 in Senegal. The workshop’s agenda and more details can be found on the workshop’s website.
—Ilham Bouimetarhan (email: [email protected]; @ilham7env), MARUM Center for Marine Environmental Sciences, University of Bremen, Germany; also at Centre des Sciences et Technique Campus Universitaire Ait Melloul, University Ibn Zohr, Agadir, Morocco; Matthieu Carré, Sorbonne University, Centre National de la Recherche Scientifique–Institut de Recherche pour le Développement–Muséum National d’Histoire Naturelle, Laboratoire d’Océanographie et du Climat: Expérimentations et Approches Numériques, Paris, France; and Rachid Cheddadi, Institut des Sciences de l’Evolution de Montpellier, Université de Montpelier, France