Floods, drought and pests are among the challenges farmers will face as the frequency of extreme weather events wreaks havoc on food production.
Evidence of climate change is obvious: in April floods in KwaZulu-Natal damaged sugar mills and cane fields; in March swarms of locusts descended on the Western, Northern and Eastern Capes; and in the past decade drought has affected most provinces.
In some sectors farmers plan to mitigate potential damage from climate change with technologies that map and predict weather patterns to better enable planting and harvesting schedules. Some use genetically modified seeds that yield plants more adaptable to drier conditions.
The UN describes climate change as long-term shifts in temperature and weather patterns, some of which may be natural, but the main driver is the burning of fossil fuels such as coal, oil and gas, which produces heat-trapping gasses.
Agri SA says Southern Africa “is anticipated to be one of the most significantly affected regions to bear the harmful consequences of climate change. This is due to the region’s reliance on already highly stressed water resources,” it said.
Anthony Clark, an independent analyst at Small Talk Daily Research, said “if you look at weather patterns in South Africa over the past 30 to 50 years, the Cape is getting drier, which means wheat harvests have been declining. Wheat is a very difficult crop to grow and is predominantly grown in the Western Cape.
“If, as the climate change scenario indicates, it will get hotter and drier in the main wheat-growing areas, we will become ever more dependent on imports.”
Clark said because of global instability and the weakness of their currencies, emerging markets will be far more exposed to imports from unstable countries as the climate changes.
“Certain crops do need significant levels of moisture to get decent yields. As we saw this year, too much rain is bad because it rots the root stock, and too little rain is also bad — you get a tight kernel and need to extract more to get the same yield,” he said.
“If climate change pans out as anticipated, certain parts of this country will become incredibly hot and unable to sustain the level of cultivars they’re used to.
“However, genetic modification of seeds has seen significant advances — they’re more tolerant to low moisture conditions. That would mean many African countries would have to change their views on genetically modified seeds, which comes with its own challenges.”
The impact of potentially poorer harvests will affect food security and jobs in a sector that employs about 844,000 people.
Some agricultural sectors are undertaking research to assess potential climate effects and mitigate against damage.
Gerard Martin, executive manager at wine industry body Winetech, said the sector conducted a number of studies regarding climate change. The project integrated remote sensing, climate and grapevine responses over six localities in four years.
In September last year the cabinet adopted the Climate Change Bill, which will make it mandatory for all levels of government to develop and implement climate-response strategies
Results from the study, published last year, found grapevines react to climate change by altering phenology, growth and ripening responses. Phenology refers to the timing of recurring biological phenomena and the environmental and climatic factors that influence them.
“Another outcome of the project was the realisation that access to climate data is extremely limited,” said Martin.
Feedback from the industry indicates that having a user-friendly platform in which climate data and geographic information system information can be integrated would be valuable to aid short- and long-term decision-making and help producers adapt to climate change.
This led to the development of an online spatial decision-support system called Terraclim as part of the Climate Change Flagship initiative.
Terraclim will provide producers with climate and terrain information all the way down to farm and field levels, giving producers tools to adapt long- and short-term management strategies to mitigate the effects of climate change.
Conrad Schutte, manager of Vinpro consultation services, said weather conditions affect grapevine phenology, while external influences such as pests, diseases, sunburn and frost influence grapevine yield and the wine’s colour, flavour, pH level, sugar and acidity.
Weather conditions also affect the timing of the growing season’s stages.
For instance, in 2021/22 the wine grape harvest season started 10 to 14 days later than normal in February due to prolonged cold, wet weather from winter going into spring. This delayed flowering and ripening.
The contrary could also be true — if the weather becomes warmer earlier in the season, these stages could be fast-tracked.
“The Western Cape is fortunate in that we experience alternating cooling and warming effects of the sea breeze on coastal regions, which helps buffer climatic extremes,” said Schutte.
The South African Sugar Association used global circulation models — computer-based simulation — to assess the potential effects of climate change.
This has helped develop associated adaptation strategies, said Terry Stanger, director of the South African Sugarcane Research Institute.
“Remote sensing [such as using satellites] may also assist the industry with early detection of any stresses that could result from climate change,” he said.
Sugar cane is highly sensitive to changes in temperature, rainfall and atmospheric carbon dioxide content as a result of climate change, said Stanger.
Using reliable modelling, the projected consequences of climate change can be positive or negative, he said. Higher temperatures allow sugar cane to develop faster, while increases in carbon dioxide are advantageous for rain-fed sugar cane because of slightly reduced water use, but there is also an expected reduction in water supply.
In September last year the cabinet adopted the Climate Change Bill, which will make it mandatory for all levels of government to develop and implement climate-response strategies.
According to the department of environment, fisheries and forestry, in 2020 the cabinet approved the National Climate Change Adaptation Strategy, which recommends the development and improvement of early warning systems for key sectors such as agriculture, health, coast and water to provide guidance on responding to climate-related risk.
In agriculture, early warning systems could include those for crop and animal disease. Coastal warning systems could include platforms that link surfing data with real-time warnings for coastal communities. A water-related early warning system could focus on hydrological drought so water restrictions can be implemented in advance.
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