Climate Change Impact
Part 10: Example – Zambia
Zambia has a climate typical of Southern Africa with cool dry winters (June to August) with hot wet summers. The potential impact of climate change was studied as part of a project enhancing the country's skills in Integrated Water Resources Management (IWRM). Temperature are expected to rise throughout the year and over the whole country with slightly higher increases in the south-east. The changes in precipitation are less consistent with some months projected to have an increase and others to have a reduction.
The Government of Zambia was fully aware of the principles of Integrated Water Resources Management. The need for climate change to integrated in water resources planning was recognised in the National Water Plan of 1994. The Water Resources Management Act of 2011 took this a stage further. This act sought to create a National Water Authority. Section 8 of the Act on ‘Functions of the Authority’ said its functions should include:
- minimising the effects of climate change
- support proactive climate change planning and management
- in consultation with the institution responsible for national statistics, establish and maintain an information system, which will be accessible by both gender, in accordance with regulations issued by the Minister providing for the content of the system, which shall include relevant hydrological, hydrogeological, meteorological, climatological, water quality, water storage and supply and use data, and relevant information on potentials for the use of water
- publish forecasts, projections and information on water resources
The aim of this project was to assist the Government in the integration of climate change into Integrated Water Resources Management.
The first, and at the time of the project only, National Communication on Climate Change prepared under the auspices of the United Nations Framework Convention on Climate Change was produced by the Ministry of Tourism and Natural Resources (MoTNR) in 2002. The report considered mitigation options. Under the heading ‘Vulnerability and Adaptation Assessment” it was estimated that maize production might fall but sorghum could increase and groundnuts remain steady. There was no clear indication of the effect on livestock. In terms of water resources, it was suggested that southern parts of the country might be particularly vulnerable.
A report on the National Adaptation Programme of Action on Climate Change was produced by the MoTNR. Zambia had experienced a number of climate related hazards over several decades. Using multi-criteria analysis, it had identified most urgent needs to prioritize ten immediate adaptation interventions. Zambia was divided into 3 ecological-climatic regions based on rainfall. The wettest regions were toward the north of the country. According to the report, the projections suggested that the wettest region would have an increase in rainfall but the drier regions would have less rainfall. The driest region is projected to produce less agricultural produce and livestock. Wildlife could be heavily stressed due to reduced rainfall and increased migration. Malaria is likely to increase in areas with increasing rainfall.
The average annual temperatures for four stations are shown on figure 1. All four stations show a similar trend: a maximum around 1930, a general fall until about 1975 and then an increase to a new maximum around 2005. Temperatures during the 5 years 1927 to 1931 were about 0.5 °C higher than temperatures from 2001 to 2004.
|Figure 1 Average annual temperature in Zambia - four representative stations|
Temperatures are lowest in June and July. In terms of geographical distribution of temperatures, they are highest in the south-east and the north though the variation is not great – most of the is in the range 22°C to 24°C.
Figure 2 shows the seasonal distribution of precipitation. It shows that rainfall is highly seasonal with very little rain in the period June to August.
|Figure 2 Average monthly precipitation - three representative stations|
There is considerable variation in rainfall from year to year. The wettest station showed a slight increasing trend and the driest station showed a slight decreasing trend. The geographical distribution of rainfall showed it as being higher to the north of the country.
Climate change projections
Climate change projections were based on the A1B scenario. This is considered to be the ‘business-as-usual’ scenario. The projection used was the average of 23 climate models used to inform the IPCC Assessment Report.
Temperatures are expected to increase by from 3.2°C to 3.9°C by the end of the century. Figure 3 shows the geographical distribution of the temperature changes.
|Figure 3 Geographical distribution of climate change|
In the case of temperature, the increases are fairly uniform throughout the year. In the case of precipitation there is a marked difference in the changes at different times of the year.
|Figure 4 Projected change in precipitation|
This shows that rainfall will decrease in the currently driest periods of the year and will increase most in the wettest periods.
Temperatures are projected to rise throughout the year and over the whole country with slightly higher increases in the south-east. In the case of precipitation there are seasonal variations in the changes. In January, there are increases in precipitation over the whole country but larger increases in the north. In November, precipitation is expected to fall over the whole country with larger falls in the south. December could be considered a ‘pivot’ month with increases in the North and reductions in the South.