Apr 11, 2007
African continent one of the most vulnerable to climate change
The Intergovernmental Panel on Climate Change (IPCC) reported in early February that scientists are now 90% certain that human activities are causing climate change. This month saw the IPCC's working group II report on the impacts of that warming.
The study found that observational evidence indicates natural systems in all continents and most oceans are being affected by climate changes, particularly temperature increases. And this time, the report goes into much more detail on a regional level, which is, after all, the factor that will have the most effect on the day-to-day lives of people and ecosystems.
Of course, the impact of climate change doesn't just depend on the actual variations in temperature, precipitation etc. themselves, but also on the ability of the affected systems to cope with the changes.
As Raj Pachauri, chair of the IPCC, put it: "people who are poor are least equipped to adapt to the impacts of climate change". That's partly why studies show that Africa is one of the most vulnerable continents to climate change.
Projections indicate that by 2020, between 75 and 250 million people in Africa will suffer an increase in water stress due to climate change. And the area of the continent suitable for agriculture is likely to decrease, particularly along the edges of semi-arid and arid regions. By 2020, yields from rain-fed agriculture in some countries could decrease by as much as 50%, exacerbating malnutrition and food security problems. What's more, rising water temperatures in large lakes may decrease fish stocks, again affecting food supplies. On the plus side, by 2050 much of the western Sahel and southern and central Africa will be unsuitable for malaria transmission. But the disease may become a problem in densely populated areas of Zimbabwe as well as the highlands of Ethiopia, Kenya, Rwanda and Burundi, which are currently malaria-free.
"Africa is the continent with the least responsibility for climate change and yet is perversely the continent with the most at risk if greenhouse gases are not cut," said Achim Steiner, executive director of the United Nations Environment Programme (UNEP). "Some measure of climate change is however a reality that the world must already live with. That reality requires assistance for Africa to adapt."
Steiner says that as well as financial investment, Africa needs investment in careful and considered planning, so that climate change becomes central to the development process, and economies are climate-proofed.
It looks like water will also cause big issues in Asia. The availability of freshwater in Central, South, East and Southeast Asia is likely to decrease due to climate change, which could potentially affect more than a billion people by the 2050s. Coastal areas, meanwhile, especially mega-delta regions, are set to suffer from too much water as a result of sea-level rise and river flooding. Flooding and droughts could increase the prevalence of diarrhoeal diseases in some areas, while increasing coastal water temperatures may well exacerbate the abundance and toxicity of cholera in South Asia. Although crop yields could increase by up to 20% in East and Southeast Asia, Central and South Asia are more likely to see yields decrease by up to a third by around 2050.
And small islands are especially vulnerable to the effects of climate change. Sea-level rise could boost phenomena such as erosion, storm surge, and inundation, damaging infrastructure and settlements, and perhaps even making the island uninhabitable. By the mid-21st century, climate change could well reduce water resources on small islands in the Caribbean and Pacific to such an extent that they cannot meet demand during times of low rainfall. Coral bleaching and beach erosion could also affect local resources such as fishing and tourism income, and higher temperatures could increase invasion by non-native species.
Although there's a wide range of adaptation options available - for example sea defences, changing food and recreation choices, different farming practices, and new planning regulations - the IPCC says that the world needs more extensive adaptation than is happening today to reduce vulnerability to future climate change. And adaptation alone is "not expected to cope with all the projected effects of climate change", especially not over the long run. So it looks like it's high time to give mitigation efforts an additional boost.
About the author
Liz Kalaugher is editor of environmentalresearchweb.