Scientists warn that the intense storms, droughts and floods South Africa is currently experiencing will increase in years to come as a result of the greenhouse ”steroids” people are pumping into the atmosphere.
They predict the western side of the country will become increasingly dry as the eastern side becomes wetter. Temperatures will rise everywhere, but more in the interior than on the coast.
Rising global temperatures are changing rainfall distribution patterns. Recent years have been among the warmest since 1860, and the United NationsÃ¢â‚¬â„¢s inter-governmental panel on climate change predicts global average temperatures are likely to rise by up to 5,8C by 2100.
”The changes are most obvious in the tail-ends of rainfall distribution, where you get extremes like droughts and floods, and in the intensity of weather,” said Bruce Hewitson, a climatologist in the University of Cape TownÃ¢â‚¬â„¢s department of environmental sciences.
Last year the South African Weather Service introduced remote sensing technology that predicts and issues warnings about severe weather such as thunderstorms, hail, high winds and tornadoes. The serviceÃ¢â‚¬â„¢s climate records showed that Phalaborwa in Limpopo experienced its highest temperature in 24 years this week, while Sutherland in the Northern Cape had its highest in 46 years.
Hewitson said the recent floods in Gauteng and drought in Cape Town were likely to become the norm as a consequence of rising temperatures, caused by the release of -carbon dioxide and other greenhouse gases by human activities such as transport and industry.
”SocietyÃ¢â‚¬â„¢s activities over the past five to 10 years have affected the chemistry of the atmosphere. The weather we are experiencing is an expression of the energy content of the atmosphere,” said Hewitson.
Bob Scholes, a systems ecologist at the Centre for Scientific and Industrial Research, said that a warmer world was a wetter world because more heat caused more evaporation, which caused more rainfall.
”When you warm up the world, you put the climate system on to steroids,” Scholes said. One of the effects would be increased storm intensity. Other effects predicted by scientists in the coming decades include the rising incidence of vector-borne diseases such as malaria, reduced crop yields and increased crop diseases, species extinctions and reduced -biodiversity.
Direct economic impacts include damage to infrastructure by extreme weather and piping water into drought-stricken areas.
Commercial fruit farmers in the Western Cape have started introducing adaptive measures to deal with rising temperatures. Some farmers are moving from apples to grape cultivation. In some cases, -producers are cooling crops with evaporative water sprayers, while most have introduced more efficient irrigation systems.
Apple growers who export their produce are worried about heat-related flaws and are researching how to use reflective powders to protect their fruit against over-heating and to prevent sunburn.
Hewitson said the biggest challenge was to find suitable long-term responses to climate change across all sectors of society. ”This affects not just individuals, but every sector of the economy,” he said.
”Carbon dioxide has a lifetime in the atmosphere of 30 to 60 years. This [problem] is not going to go away in our lifetime, or even those of our children.”
One of the main resolutions to emerge from the United Nations conference on climate change in Montreal late last year was agreement on a five-year scientific work programme on adapting to climate change. Starting this year, the programme will see scientists make recommendations on practical measures to adapt to the adverse impacts.
”The international community is finally facing up to the fact that -climate change impacts are a reality, and developing countries in particular need support to adapt,” said Elin Lorimer, of the South African Climate Action Network, a member of the government delegation at -Montreal.
”People are realising that the impacts of climate change are here already, that they are not just something for the future.”
Pressures on reserve resources grow
As northern Kenyans starve in the worst drought to hit the country in 22 years, Maasai herders are driving their emaciated cattle into national game parks and on to the lawns of suburban homes in the capital, Nairobi, writes Fiona Macleod.
While parts of Mozambique and South Africa are experiencing floods, Kenya and other countries in the Horn of Africa are crippled by drought because they have different weather systems.
The United Nations Environment Programme warned this week that the Kenyan drought was deepening because of global climate change and the destruction of forests and other critical ecosystems.
”Drought is no stranger to the peoples of East Africa,” said Klaus Toepfer, the programmeÃ¢â‚¬â„¢s executive director. ”What has dramatically changed in recent decades is the ability of nature to supply essential services like water and moisture during hard times.”
South African environmentalists said pressures on wildlife reserves could be expected to grow as a result of rising temperatures and weather extremes. ”We have noticed an increased demand from communities living close to our parks for natural resources,” said Jimmy Masombuka, spokesperson for the Mpumalanga Tourism and Parks Agency. ”There are less resources available outside the parks, and some are finished. This is because there are more people using the resources outside the parks, and also because of floods and droughts.”
The new Protected Areas Act allows rural communities access to resources such as firewood inside parks, but not to graze livestock.
Masombuka pointed out that, unlike Kenyan parks, South AfricaÃ¢â‚¬â„¢s reserves were fenced and were unlikely to be invaded by cattle herders. But there was a growing demand for resources like medicinal plants and bushes used for brooms.