by Tigere Chagutah – SANF 07 No 17
The frequency and intensity of dry spells and flooding in southern Africa is expected to increase as weather experts warn of a surge in world temperatures.
A report recently released by the Inter-governmental Panel on Climate Change (IPCC) shows that drying of the land has been observed in southern Africa, the Sahel, the Mediterranean and parts of southern Asia over the last century.
IPCC noted that the period 1995-2006 ranks among “the 12 warmest years in the instrumental record of the global surface temperature”. The first record of global surface temperature was in 1850.
The IPCC was set up by United Nations Environment Programme and the World Meteorological Organisation to assess scientific, technical and socio-economic information important for the understanding of climate change, its potential impacts and options for adaptation and mitigation.
According to IPCC, global temperatures are expected to rise by between 1.8 and four degrees Celsius by the end of the 21st century.
Reporting in the first volume of its Fourth Assessment Report, the IPCC said climate change impacts for the affected regions will include less predictable weather characterised by frequent and heavier flooding, more intense and longer droughts and rising sea levels.
Cyclonic activity is also expected to become more intense with larger peak wind speeds and heavier rains.
The Southern African Development Community (SADC) region has experienced increased cases of flooding, cyclones and dry spells over the past three decades.
Research shows that the SADC region has experienced at least two droughts per decade.
The severity of the dry spells has worsened over the years, with the 1991/92 season being declared the worst drought in living memory for the SADC region – which stretches from Tanzania on the east African coast to South Africa and comprises 14 countries.
The 1994/95 season was another dry period, with some SADC countries experiencing worse conditions compared to the 1991/92 drought.
The seasons since 2001 have also been drought years, except for the 2003/04 and 2005/06 seasons when sufficient and well-distributed rains were received to guarantee food security in the region.
Zimbabwe has declared the 2006/07 season as a drought period amid warnings of El Niño conditions normally associated with dry spells in southern Africa.
The El Niño conditions were detected in September 2006 and their development has been closely monitored since then.
El Niño episodes are generally associated with depressed rainfall conditions in the southern parts of the SADC region, which include parts of Zambia, Zimbabwe, Botswana, Namibia, South Africa, Mozambique and Madagascar, especially during the critical period of the crop cycle from December to February.
In northern United Republic of Tanzania and other parts of east Africa, El Niño is normally associated with heavy rainfall and flooding.
The changing climatic conditions have also witnessed frequent cases of cyclonic activity, characterised by severe flooding and destruction of infrastructure due to strong winds.
The most recent one was Cyclone Favio in late February, which affected Madagascar, Mozambique and parts of Zimbabwe.
Parts of Angola, Madagascar, Mozambique, Namibia and Zambia were also struck by devastating floods this year that destroyed crops.
Unpredictable rainfall is expected to put a strain on the fragile food security in a region in which the main staple maize is particularly susceptible to drought.
Crop yields and agricultural productivity are expected to decline due to reduced soil moisture and increased incidence of animal and crop pest attacks.
Experts say increased temperatures will be conducive to a rise in pest populations while also reducing soil moisture, moisture storage capacity and overall quality of the soil.
