Analyzing Regional Climate Change in Africa in a 1.5, 2, and 3°C Global Warming World

Abstract

At the 21st session of the United Nations Framework Convention on Climate Change Conference of the Parties (COP21) in Paris, an agreement to strengthen the effort to limit the global temperature increase well below 2°C was decided. However, even if global warming is limited, some regions might still be substantially affected by climate change, especially for continents like Africa where the socio‐economic conditions are strongly linked to the climatic conditions. In the paper we will discuss the analysis of indices assigned to the sectors health, agriculture, and infrastructure in a 1.5, 2, and 3°C global warming world for the African continent. For this analysis an ensemble of 10 different general circulation model‐regional climate model simulations conducted in the framework of the COordinated Downscaling EXperiment for Africa was investigated. The results show that the African continent, in particular the regions between 15°S and 15°N, has to expect an increase in hot nights and longer and more frequent heat waves even if the global temperature will be kept below 2°C. These effects intensify if the global mean temperature will exceed the 2°C threshold. Moreover, the daily rainfall intensity is expected to increase toward higher global warming scenarios and will affect especially the African Sub‐Saharan coastal regions.

Drier tropical forests are susceptible to functional changes in response to a long‐term drought

“…Given the expected changes in climatic conditions in the near future, especially in Western Africa where the average rainy season length is expected to decline (Weber et al . ), it is imperative we are able to predict how different forest types may respond to these modifications (e.g. by being resilient or resistant to such changes).…”

“…Although we show that forest communities are not being 'resilient' per se (see Hodgson et al 2015) and have shifted their trait composition across time, such shifts may actually enhance the resilience of ecosystem functions, for example reduce the likelihood of the forest shifting into a savannah. Given the expected changes in climatic conditions in the near future, especially in Western Africa where the average rainy season length is expected to decline (Weber et al 2018), it is imperative we are able to predict how different forest types may respond to these modifications (e.g. by being resilient or resistant to such changes).…”

Persistence of the high solar potential in Africa in a changing climate

“…Changes in austral spring are as in austral autumn, but with larger increases of solar radiation in southeastern Africa, including Mozambique, Madagascar, Zimbabwe and Tanzania, and solar radiation decrease in Somalia and northern Kenya. These changes are closely linked to the projections of future cloud cover and precipitation modifications, pointing to decreases in precipitation in southern Africa and significant increases in Ethiopia and neighbouring countries (Weber et al 2018. When looking to the projections according to RCP4.5 analogous patterns appear but with changes in the magnitude of the order of half of those of RCP8.5 ( figure S6), except to the areas where changes are small such as in central western Africa.…”

The effects of 1.5 and 2 degrees of global warming on Africa in the CORDEX ensemble

“…Haensler et al 2013, Pinto et al 2015, Dosio 2017, see for more references an introductory paper to this focus collection-Lennard et al in review). However, only a few studies have used the CORDEX Africa simulations for assessment of climate risks of the 1.5 and/or 2 • C global warming levels in Africa (Déqué et al 2016, Weber et al 2017. Focusing on 1.5 • C is more challenging since the point in time when this GWL is reached is much closer than the commonly used end of the century and natural variability can strongly dominate on such near-term time periods, especially at the regional scale (e.g.…”