Publications
- Sub-Saharan Africa has experienced reduced maize and wheat yields due to climate change.
- Climate change has reduced agricultural productivity in Africa by more than a third since 1961.
- It's not all "doom and gloom" for agriculture, heavy rainfalls have boosted other crop yields such as sugar cane.
Climate change has significantly reduced crop yields in Africa, with wheat and maize being among those negatively affected in the Sub-Saharan Africa region, a new study shows.
The UN's Intergovernmental Panel on Climate Change on Monday released its Working Group II report, Climate Change 2022: Impacts, Adaptation and Vulnerability. This report follows on the Working Group I report released in August 2021, which provided scientific evidence of the physical changes to climate. The most recent report sheds light on the irreversible consequences of global warming beyond 1.5°C for people and ecosystems in different world regions.
The report shows that in Africa, climate change has reduced agricultural productivity growth by more than a third (34%) since 1961. This is more than any other region.
"Future warming will negatively affect food systems in Africa by shortening growing seasons and increasing water stress. Global warming above 2°C will result in yield reductions for staple crops across most of Africa compared to 2005 yields," the report read.
In Sub-Saharan Africa, staple crops like maize and wheat have already seen reductions due to climate change, explained Christopher Trisos, one of the report's African authors and senior researcher at the African Climate and Development Initiative at the University of Cape Town.
Trisos, who was speaking during a press briefing focused on the impacts on Africa, added that the increase in carbon dioxide in the atmosphere and changing rainfall in South Africa and southern Africa has resulted in the expansion of woody vegetation - such as trees and shrubs - into grasslands. Furthermore, savannahs have expanded, reducing grazing land or pastures. This has had a negative knock-on effect on eco-tourism, as it is difficult to see animals through thick vegetation, Trisos said.
There has also been an increase in the distribution of vector-borne diseases and parasites like ticks for livestock. Other negative impacts on livestock include decreasing fodder availability - as woody plants encroach on grazing lands. Reduced grazing land and water has also contributed to starvation, malnutrition and death.
Climate change also poses a further threat to African fisheries. Reduced fishing harvests due to global warming under 1.7°C can leave millions of Africans with vitamin deficiencies.
Daniel Olago, of the Institute for Climate Change Adaptation and Department of Geology at the University of Nairobi, said it is not all "doom and gloom" for the agriculture sector. There have been some opportunities - for example, the heavy rainfalls in major dry regions have recharged groundwater systems. There is an opportunity to "exploit" the groundwater as a buttress for agriculture.
Co-author Edmond Totin, and research scientist at the International Crops Research Institute for the Semi-Arid Tropic, added that climate change positively impacted other major products like sugar cane in southern Africa and palm oil in West Africa.
Extreme droughts
The report flagged droughts as a "major driver" of food insecurity and reduced crop yields. Climate change is causing droughts to become more frequent and severe. South Africa and California reported the worst droughts on record in the past decade, the report indicated.
The report notes that between 2015 and 2017, the Western Cape region experienced three consecutive years of below-average rainfall, which led to water shortages in Cape Town. Human-induced climate change made the drought "five to six times more likely", the report read.
In 2018, the Western Cape's water supply was reduced to 20% of capacity (compared to 97% in 2014). Agricultural yields declined by 25% in the following year.
The report also highlights the negative impact of climate change on tourism. Extreme heat days have increased in South African national parks since the 1990s - and has reduced animal mobility and decreased opportunities for tourists to view them.
"Tourists and employees also fear heat stress. Visitors to South Africa's national parks preferred to visit in cool to mild temperatures. Extreme weather conditions disrupted tourist activities and damaged infrastructure at Victoria Falls, Hwange National Park, Kruger National Park and the Okavango Delta," the report read.
The report also flagged the negative impact of extreme weather events such as floods on businesses - with the potential to deepen poverty.
Human life is not spared of the harsh effects of climate change. In South Africa, between 1991 and 2018, human-induced climate change was responsible for nearly half (43.8%) of heat-related mortality. "In many of South Africa's 52 districts, this equates to dozens of deaths per year. The elderly and children under five years are most vulnerable to heat exposure," the report read.
The report also indicates that mental health and well-being are affected by local climate conditions. Extreme weather is also associated with increasing rates of anxiety, post-traumatic stress disorder and depression.
Escalating risks
Trisos said he was most concerned that climate change risks and impacts will increase in the near term as global warming approaches 1.5°C. Warming beyond 1.5°C and below 2°C will see these risks become more severe, with irreversible impacts such as species extinctions. "We are not ready for that," he said.
