Frequency and intensity of heavy precipitation events projected to increase across the continent
Human-induced global warming has been more rapid in Africa than the rest of the world, according to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).
Average annual maximum temperature in northern and southern Africa is likely to be close to four degrees Celsius above normal, according to regional projections in the report released August 9, 2021.
The median temperature in these regions will rise 3.6°C when the earth warms at 2°C above pre-industrial levels, predicted the group of scientists who authored the report.
The annual minimum temperature is also projected to increase by over 2°C in some parts of northwestern Africa, the analysis showed.
Southern Africa will also see a rise in minimum temperature. This will lead to warmer cold days in the future, according to the authors.
In 2021, Africa experienced its fourth-warmest April since 1910, with a temperature anomaly of 1.48°C, according to the National Oceanic and Atmospheric Administration (NOAA).
Extreme heat waves will continue to increase and extreme cold waves will decrease throughout the 21st century, with additional global warming, according to IPCC.
Africa accounts for just 3.9 per cent of carbon dioxide emissions, according to Global Carbon Atlas, a repository of data on human-induced and natural carbon fluxes.
Frequent extreme rainfall
At 1.5°C global warming, heavy precipitation and associated flooding are projected to intensify and be more frequent in most regions in Africa, the report said.
With additional increases in global warming, changes in hot and cold temperature extremes, the frequency and intensity of heavy precipitation events are projected to increase almost everywhere in Africa, warned IPCC in its projections for the continent.
The relative sea level around Africa has increased at a higher rate than the global mean sea level rise over the last three decades. This trend is likely to continue in the region, the researchers wrote.
The rate of sea-level rise has reached five millimetres (mm) per year in several areas on the continent’s coastline, especially along Eastern Africa, according to a World Meteorological Organization report.
In southwestern Indian Ocean from Madagascar, eastward towards and beyond Mauritius, it has even exceeded 5 mm a year. This is above the rate of average global sea-level rise of around 3-4 mm each year.
Increase in global warming will contribute to increases in the frequency and severity of coastal flooding in low-lying areas due to coastal erosion, mostly along sandy coasts, according to the IPCC assessment.
Monsoon precipitation is projected to increase over Central Sahel and decrease over the far western Sahel. The monsoon season is projected to have a delayed onset and a delayed retreat, as stated in the report.
At 2°C global warming, precipitation is likely to increase by 5-40 per cent in Sahara, including parts of the Sahel.
There has been an increase in monsoon precipitation during the 20th century due to warming from greenhouse gas emissions, noted the IPCC report. But this has been masked by the decrease due to cooling from human-caused aerosol emissions.
West and Central Africa is likely to experience heavy precipitation and pluvial flooding.
Increased cyclones, droughts
The average tropical cyclone wind speeds are likely to increase in East Southern Africa, according to IPCC.
This may lead to increase in the heavy precipitation and more Category 4-5 (severe) tropical cyclones in the region.
Climate change is expected to make Category 5 storms stronger and more numerous in the coming decades, according to Jeff Masters, hurricane scientist with the NOAA.
Marine heat waves that have become more frequent since the last century are projected to increase around the continent.
With global warming of 2°C global warming and above, several regions in Africa are projected to experience an increase in frequency and / or severity of agricultural and ecological droughts.
Aridity and droughts will increase across Mediterranean (Northern Africa), Western Africa, West Southern Africa and East Southern Africa, the report projected.
While Madagascar is suffering from the worst drought in 40 years, the future seems to be grimmer, according to the IPCC projections.