Fighting climate change through forecasting

South African Weather Service

Fighting climate change through forecasting

Last year was among the hottest the globe has experienced. While South Africa did not experience its hottest year (recorded in 2019), temperatures still placed it as the 13th hottest year in South African records.

These soaring temperatures are becoming increasingly common as we witness climate change. One of the best tools to allow us to adjust to warmer temperatures and severe weather events lies in weather forecasting.

A VITAL TOOL

In South Africa, the South African Weather Service (SAWS) is the authority for weather and climate forecasting. The SAWS is mandated to provide meteorological services, including producing weather forecasts, issuing severe weather warnings, and drawing up seasonal outlooks for farmers and the Department of Agriculture.

The SAWS also produces forecasts for the aviation industry and maritime weather forecasting services for the oceans between South Africa and Antarctica.

SAWS is a member of the World Meteorological Organization and operates as a Department of Environmental Affairs agency.

The organisation runs several research initiatives into climate change alongside its forecasting services. These include ways to downscale the possible effects of climate change and determine its impacts on a local scale.

Weather forecasting is essential. It's critical for agriculture, offering farmers a guide on when to plant or protect crops and industries such as shipping and aviation.

But beyond its commercial applications, accurate forecasting can help save lives and reduce property damage by

predicting severe weather events. These extreme weather events are more likely to occur as the effects of climate change worsen. Weather forecasting is a complex process. It relies on observing atmospheric models, including information on temperature, pressure, humidity and wind speed. This information is combined with the data from hundreds of weather stations around the country to create a forecast using the latest computing technology.

Yet the atmosphere is so vast and complex that even a tiny change in pressure over the ocean can completely change a forecast. It's almost impossible to have a 100% accuracy rate, although this may gradually change as more technology advancements become available.

TEMPERATURES ON THE RISE

Thanks to climate change, South Africa has been recording more maximum temperatures and more frequently than expected. These rising temperatures can lead to droughts and heatwaves, decreasing crop yields and risks to human health, such as the spread of pests and pathogens.

But it's not just Southern Africa that's affected. Data from Berkeley Earth - an independent environmental data science organisation in the USA – showed that in 2020 global temperatures warmed by 1.3 degrees Celsius. During the same year, temperatures increased by 1.6 degrees Celsius in South Africa. The United Nation's Intergovernmental Panel on Climate Change (IPCC) found that if global temperatures reach or exceed 1.5°C of warming, the world will likely see more heatwaves, longer summers and shorter winters.

This will have an especially devastating effect on Sub- Saharan Africa, with extreme temperatures and increased natural disasters likely to leave millions injured, homeless, or food insecure – essentially causing untold economic damage.

HOW CAN INDIGENOUS KNOWLEDGE IMPROVE WEATHER FORECASTING?

While weather forecasting strongly relies on scientific data, another kind of information can help strengthen forecasting models. This information is indigenous ecological knowledge. Many communities across the continent have longheld knowledge about their environments and the trends and shifts in them. For example, the "rainmakers" from the Nganyi community in western Kenya have historical knowledge about the region's weather patterns and use plants and animals to follow weather changes. This community now works with Kenya's Meteorological Department to produce seasonal weather forecasts.

A similar project is under way in the Mwenezi and Chiredzi districts in Zimbabwe. The Seasonal Participatory Scenario Planning project sees meteorologists, community members, local government departments and NGOs sharing scientific and traditional indigenous knowledge to build a hybrid localised seasonal outlook for farming seasons.

However, this valuable indigenous knowledge is slowly being lost as elders and custodians of it pass away. In addition, many of the indigenous plants and animals used by these communities to track weather patterns are under threat.

WHAT IS CLIMATE CHANGE?

Our impact on the environment is leading to changes to the world's climate beyond what would be considered natural variations. The climate goes through warm and cold periods, taking hundreds of years to complete one cycle – yet our impact on the environment is causing this cycle to speed up. These temperature changes affect rainfall patterns and other weather phenomena, and plants and animals may struggle to adapt to warming temperatures if the climate changes too quickly. Climate change is driven by greenhouse gasses and the energy of the sun. These gases in the atmosphere trap the energy from the sun and warm the earth. However, human activities, such as burning fossil fuels and deforestation, have increased the concentration of greenhouse gases in the atmosphere. This is causing warmer temperatures. Climate models estimate that the mean air temperature over South Africa will increase by 2 degrees Celsius over the next 100 years. •

Sources: www.allafrica.com www.bbc.com www.dailymaverick.co.za www.dffe.gov.za www.imf.org www.news24.com www.vox.com www.weathersa.co.za