Globe Briefing on Climate Change and Effects on Water

PORTFOLIO COMMITTEE ON WATER AFFAIRS AND FORESTRY
5 April 2001
GLOBE BRIEFING ON CLIMATE CHANGE AND EFFECTS ON WATER

Chairperson: Ms BP Sonjica

Documents handed out:
GLOBE Parliamentary Lectures (See Appendix)

SUMMARY
Sustainable Energy and Climate Change Partnership made a presentation on global climate change and the factors that influence it, including the burning of fossil fuels and the chopping down of tropical rain forests.

MINUTES
Mr Richard Sherman of Sustainable Energy and Climate Change Partnership (SECCP) gave a presentation on how climate change has been central to the United Nations global environmental governance debate. The United Nations Framework Convention on Climate Change came in 1992 and will have its 10^th Anniversary in May 2002. It is a very broad and encompassing Convention.

Under the Convention, Globe looks at and addresses human-induced climate change. This includes the burning of fossil fuels, coal, and gas, the use of oil, and the chopping down of rain forests. Once gases are released, they get trapped in the atmosphere and begin to block the sun's ultraviolet rays.

Within the first three months of this year, the Intergovernmental Panel on Climate Change, a United Nations institution of 2 500 of the world's top scientists, has released three reports that indicate damaging results of climactic change, particularly on the African continent. The reports look at issues of increased flooding, the lack of distribution of water resources and health problems. The reports suggest the impact of climate change in southern Africa will be felt on our freshwater resources. Both South Africa and the surrounding countries are already facing problems in dealing with water resources and the fact that some southern African countries are moving toward a water stress situation. Furthermore, predictions indicate that temperatures will become hotter. In this way, climate change is becoming a burden to water resource management in South Africa and the surrounding regions.

Effects of climate change on water resources
- The doubling of carbon dioxide will have an impact on how much water our plants absorb
- A rise in sea level will have an impact on freshwater systems that are close to coastal areas
- Changes in seasonal precipitation
- Changes in drought hazards and
- Changes in flood hazards.

Mr Sherman also addressed the vulnerability of southern Africa's water resources and the issue of evaporation in that southern Africa experiences a very high loss of water from evaporation and transpiration.

Discussion
Mr R September (ANC) remarked that the Committee had been rushed with Mr Sherman's presentation as it the took place during lunch period just before a parliamentary sitting. He expressed the hope that Mr Sherman would be free to address the Committee at a later occasion when he would be given more time.

The Chairperson concurred and added this was too important a session to have been allocated so short a period of time. She said the Committee would take that into consideration and probably give Mr Sherman another opportunity to make another briefing.

Mr Sherman replied that his organisation would be happy to brief the Committee whenever requested.

An ANC member commented the content of the lecture was very ominous on the subject of global climate change, particularly in that the African continent is the most vulnerable. He asked the presenter to outline solutions. Furthermore, he said that this problem is not one that can be addressed by states in their individual capacities. He asked if there were any efforts made by different states in their joint capacities to devise a possible solution for this problem.

Mr Sherman replied nothing much has been done in terms of addressing climate change and freshwater issues. There is a need for states to co-operate together in addressing these issues. It is up to South Africa and its partners in the SADC region to ensure that this process moves forward.

Ms J Chalmers (ANC) asked if South Africa is learning from experiences of countries that are particularly vulnerable to the ozone layer such as Australia. If so, are there any practical adaptations for South Africa.

Mr Sherman replied they do look at what other states are doing in terms of identifying solutions.

Prof H Ngubane (IFP) said that she was confused about the fact that South Africa has been classified as a developing country. If so, what is its status vis a vis other poor countries on the African continent.

Mr Sherman replied that the classification of South Africa as a developing country was made by the United Nations Framework Convention on Climate Change. It classifies the world into developing and developed.

Ms J Semple (DP) commented that the presentation suggests South Africa is in serious trouble as far as water is concerned. She referred to an example in the Western Cape where restrictions on water use are applied. Periodic restrictions are also enforced in Gauteng. She asked if Mr Sherman would make a comment on whether all the provinces in the country should impose restrictions as a whole, particularly in terms of irrigation and for agricultural purposes.

Mr Sherman replied the need to impose restrictions on the use of water involves a question of balance between those who use too much and those who do not. Restrictions have been imposed to a certain degree. Other factors that are taken into account include climatic conditions such as periodic dry seasons.

The meeting was adjourned.

Appendix

Abstract

Water is needed in all aspects of life. The general objective is to make certain that adequate supplies of water of good quality are maintained for the entire population of this planet, while preserving the hydrological, biological and chemical functions of ecosystems, adapting human activities within the capacity limits of nature and combating vectors of water-related diseases.

Agenda 21 - United Nations Conference on Environment and Development 1992

South Africa faces a number of problems related to the efficient utilisation of the country's scarce water resources. These problems are exacerbated during dry seasons and drought periods when rural water supply schemes fail, river ecosystems endure severe stress and water pollution becomes critical and extremely difficult to manage.

One of the greatest potential impacts of climate change on human society is through its effect on freshwater resources.[1] The most critical factor associated with climate change impact is the availability of water resources. People dependent on river basins and wetlands face losses of freshwater biodiversity and a reduction in ecosystems services such as water supply, water purification and flood control. Communities dependent on agriculture and subsistence farming face chronic food shortages, economic and livelihood constraints.

Climate change will persist for many centuries, due to the long life of greenhouse gases in the atmosphere and the long time required for transfer of heat from the atmosphere to the deep oceans; even with quick action to curtail emissions, the effects of our current activity will be felt for hundreds of years.[2] There is already a growing scientific understanding that the conservation and sustainable use of freshwater resources can no longer be achieved without taking climate change into account. This lecture highlights the impacts and opportunities of climates on:

Water supply and stress for domestic use
Water supply for industrial use
Water borne diseases and related health problems
Agricultural production and land use
Water supply for hydro-electricity generation
Impacts on tourism and water for recreation
Biodiversity, wetlands, desertification and other environmental impacts

Freshwater and Climate Change

Water plays a complex and multi-facetted role in both human and natural systems. It is an issue that cuts across many thematic sectors such as agriculture, energy, human settlements, livelihoods, tourism, health, industry, recreation, wildlife, and forestry. Traditionally, water management has focused on the direct provision of water for people to drink, grow their food and support industries.

However, as water is a priority resource, there is now a need to understand its actual and potential sustainability from a regional and local perspective in the context of the watershed as the system of analysis. Small changes in the ecological system may have significant and dynamic responses on water quality, quantity and distribution.

Today, the world and South Africa are struggling with freshwater management and sustainability. Many areas face increasing water stress, millions of people remain without access to basic water services and even more millions die annually from preventable water related diseases. Human induced impacts and environmental degradation are placing increased stress on existing and future water resources.

Climate change will affect both water demand (related to higher temperatures) and water supply (The balance of CO2 enrichment, evapotranspiration and precipitation)[3] The major effect of climate change on Africa's water systems will be through changes in the hydrological cycle, the balance of temperature and rainfall. There is some concern that the negative impacts of climate change on water supply could actually be larger and the gains smaller than has previously been reported in current assessments (Ringuies et al 1997). Climate change may affect development directly through changes in precipitation, evaporation and hydrology, sea-level rise, and changes in the occurrence of extreme weather events (floods, droughts, storms) that would impact on primary production, ecological systems, public health and poverty. Increased intensity of droughts, floods and changes to growing seasons may have significant implications for soil productivity, water supply, food security, and in turn human welfare and poverty, as well as deleterious and, in many cases, irreversible impacts on biological diversity.

According to the Intergovernmental Panel on Climate Change Second Assessment Report (1995), changes in climate will lead to an intensification of the global hydrological cycle and could have major impacts on regional water resources. Climate change may also lead to shifts in the geographical distribution of wetlands and an increase in the severity and extent of coral reef bleaching and mortality. Further, sea-level rise and increases in storm surges associated with climate change could result in the erosion of shores and habitat, increased salinity of estuaries and freshwater aquifers, altered tidal ranges in rivers and bays, changes in sediment and nutrient transport, increased coastal flooding, and in turn, increase the vulnerability of some coastal populations.

Water resources are inextricably linked with climate. Therefore the prospects of global climate change have serious implications for water resources and regional development (Riebsame et al., 1995). Efforts to provide adequate water resources for Africa already confront a number of challenges, including population pressure, problems associated with land use such as erosion/siltation, and possible ecological consequences of land-use change on the hydrological cycle. Climate change will make addressing these problems more complex. (IPCC 1996)

Climate change will have both adverse and beneficial impacts on natural and socio-economic sectors. The biological and economic productivity will decrease for some sectors, but increase for others. Natural resource sectors and biological diversity could in extreme cases be severely affected, reduced or depleted (CICERO). In developing countries whose economies often to a large extent rely on climate sensitive sectors, adverse climate change impacts could inflict damage to the national economy. A 2001 report by Munich Re insurers, members of the United Nations Environment Programme's (UNEP) financial services initiative concluded that, “ global warming may cost the world several billion dollars a year unless urgent efforts are made to curb emissions of carbon dioxide and the other gases linked with the "greenhouse effect". The report indicates that losses due to more frequent tropical cyclones, loss of land as a result of rising sea levels and damage to fishing stocks, agriculture and water supplies, could annually cost around $US 304.2 billion.�[4]

Climate change is likely to impact seriously on Africa. The 1995 IPCC Regional Scenarios concluded, “ Africa is believed to be the continent most vulnerable to the impacts of projected changes in the climate.�

Water supply undoubtedly is a most important resource for Africa's social, economic, and environmental well being. Currently, about two-thirds of the rural population and one-quarter of the urban population are without safe drinking water, and even higher proportions lack proper sanitation. Climate change will likely make the situation more adverse. The greatest impact will continue to be felt by the poor, who have the most limited access to water resources.

Affects of Climate Change on Water Resources

Source: Lasse Ringius, Thomas E. Downing, Mike Hulme, Dominic Waughray and Rolf Selrod Center for International Climate and Environmental Climate Change in Africa - Issues and Challenges in Agriculture and Water for Sustainable Development Report 1996:8

The New Science

In January 2001, the Intergovernmental Panel on Climate Change (IPCC), the world's leading climatologists concluded that global warming is happening faster than previously predicted. The new science assessment anticipated that the increase in temperature over this century has increased from a range of 1 - 3.5° C to 1.5 - 6°C over the next 100 years. The report projects more extreme events such as storms, floods and droughts as a consequence of increased emissions of greenhouse gases.

In February the Working Group II of the Intergovernmental Panel on Climate Change (IPCC) found that developing countries are most at risk from climate change.  Global increases in temperature would produce net economic losses in many developing countries for all magnitudes of warming and these losses would be greater the higher the warming. "The effects of climate change are expected to be greatest in developing countries in terms of loss of life and relative effects on investment and the economy.  For example, the relative percentage damages to GDP from climate extremes have been substantially greater in developing countries than in developed countries.� Another finding is that: “The projected distribution of economic impacts is such that it would increase the disparity in well-being between developed countries and developing countries, with disparity growing for higher projected temperature increases (medium confidence).�

The IPCC WGII report also concluded that regional impacts, like flooding are becoming more severe. Among the report's conclusions are that current rates of human-induced climate change will have extensive regional impacts, particularly in Africa, such as

The impacts of climate change threaten large populations of Africa already struggling for sustainable development.
Grain yields are projected to decrease for many scenarios, diminishing food security, particularly in small food-importing countries (medium-high confidence).
In a region already facing the effects of AIDS and malnutrition, climate change will foster the expansion of a host of infectious diseases.
Extension of ranges of infectious disease vectors would adversely affect human health in Africa (medium confidence).
Floods, famine, and refugee migrations are very likely as climate change tips the balance in overburdened regions of the African continent.
Increases in droughts, floods, and other extreme events would add to stresses on water resources, food security, human health, and infrastructures, and would constrain development in Africa (high confidence).
As climate change grips Africa and vital ecosystems wither, some of the richest biodiversity on Earth is likely to disappear.
Significant extinctions of plant and animal species are projected and would impact rural livelihoods, tourism, and genetic resources (medium confidence).

The Report outlines the following general climate threats:

Increased frequency of heat waves will increase crop and livestock losses, frequency of wildfires, wildlife mortality, energy demand for cooling, and human deaths and illness from heat stress and air pollution.
Decreased frequency of cold waves and fewer frost days will extend the range of some pests and disease vectors while reducing losses due to cold.
Increased frequency of high intensity rainfall will increase flood (and flash flood) risk, with consequent property damage, soil erosion, flushed pollutants, health threats, and deaths.
More frequent drought in mid-latitude continental interiors will increase agricultural losses, threaten terrestrial and aquatic ecosystems, reduce quality and availability of water with consequent health effects, and promote land subsidence.
Increased intensity and frequency of tropical cyclones will threaten property, coastal stability, ecosystems, health, and life.
Any increase in intensity and frequency of extreme climate events will increase demands on already overburdened public and private financial mechanisms to cover weather related losses.

How Vulnerable are Southern Africa's Water Resources?

South Africa

The climate in South Africa is typically warm and dry, with winter temperatures rarely falling below 0°C, and summer maxima frequently above 35°C. The country also falls within the subtropical belts of high pressure, making it dry, with an abundance of sunshine.  The wide expanses of ocean on three sides of South Africa have a moderating influence on its climate, although gale force winds frequently occur on the coastlines. South Africa lies within a drought belt with an average annual rainfall of only 464 mm, compared to a world average of 857 mm.  Twenty-one per cent of the country has an annual rainfall of less than 200 mm, 48 per cent between 200 and 600 mm, while only 30 per cent records more than 600 mm.  In total, 65 per cent of the country has an annual rainfall of less than 500 mm.

Studies in South Africa have shown that there has been more than a 1^oC increase in temperature over South Africa since the beginning of the century (Hulme, 1996; Mason and Jury, 1997). South Africa's rainfall is erratic in distribution and variable between years.  Most of the country is arid and subject to droughts and floods.  South Africa's industrial, domestic and agricultural users are highly dependent on a reliable supply of water.  Even without climate change, South Africa is predicted to have exhausted its surface water resources early in the 21^st century.  A reduction in rainfall amount or reliability, or an increase in evaporation (due to higher temperatures) would exacerbate this situation. The arid and semi-arid regions, which cover nearly half of South Africa, are particularly sensitive to changes in precipitation because the fraction of rainfall that is converted to runoff or percolation to groundwater is small (Schulze, 1997a).  Equally important consequences of global warming are the potential changes in the intensity and seasonality of rainfall.  Increased convective activity could increase the frequency and intensity of rainfall events, augmenting runoff volumes and potentially causing higher soil losses (Schulze, 1997b).

Southern Africa

Southern Africa ranges in climate from semi-arid to hyper arid, with only a few relatively humid areas where the rainfall greatly exceeds 500mm a year. [5] The Southern African region comprises various natural environments and has a variety of tropical and temperate zones. The mostly arid and semi arid regions are characterised by a large availability in the annual mean rainfall. Regional estimates put renewable freshwater resources at an annual average of 650 billion m3, which is distributed amongst rivers, lakes and groundwater bodies throughout the region (SADC 1998) The average annual rainfall varies across the region, from more than 1 500mm in the northern and north-eastern parts, to less than 25 mm in the very arid Namib Desert in the south-west (DRFN), leaving some areas with abundance of water and others a scarcity.

Over the past 20 years there has been noticeably less rainfall in Southern Africa with 1991/92 and 1 994/95 wet seasons being of the 5 driest this century. (WWF Climate Change in Southern Africa, 1998) The 1991/92 drought in Southern Africa put between 18 to 20 million people at risk of starvation. (Zero 1996,WWF, 1998). Authorities estimated that more than 5 million Zimbabweans and half the country's population, faced, hunger due to large crop failure from the 94/95 drought, and the worst experienced in the region's history. Lakes such as Victoria, Malawi and Tanganyika are in delicate hydrological balance - small changes in the temperatures and rainfall could result in lower lakes levels (Arnell et all, 1996), Lake Victoria has dried out completely in past eras.

At the same time, floods from occasional torrential rains have in some areas brought about extensive damage to property and death to people and wildlife. After the 1994/1995 droughts, large floods occurred in the Limpopo and Incomati Rivers in 1996. In the same year the Pungue River also experienced devastating floods. (SADC). Historical flooding event documentation indicated that flooding on national levels is fairly frequent, with the occurrence of significantly damaging floods in South Africa is on average between once and twice a year.

A WWF study Climate Change and Southern Africa, commissioned by WWF and co-ordinated by Dr. Mike Hulme of the Climate Research Unit (CRU), at the University of East Anglia, UK assessed the impact of Climate Changes based on Intergovernmental Panel on Climate Change (IPCC) methodologies. Three alternative climate change scenarios, "core," "dry," and "wet� were assessed. All three scenarios are based on a temperature rise of 1.7° C by the 2050s decade. This is agreed by the IPCC scientists to be the most likely amount of warming assuming little or no action is taken to reduce greenhouse gas emissions (without taking into account the slight moderating effect of aerosols in the atmosphere).

The "core" scenario points to modest drying over large parts of the region, plus widespread increases in rainfall variability. In Zimbabwe, this scenario would result in around a 5% decrease in annual rainfall, and this in turn would translate into agricultural problems, with yield reliability for the staple maize crop declining. Changes in surface water availability would reduce farmers' ability to use irrigation in compensation for poor rainfall. The "dry" scenario shows that rainfall could decline by as much as 10% across the region, while under the "wet" scenario most of the region gets wetter.

The severity of these changes will depend on the effects of increased CO2 concentrations, altered precipitation and soil moisture, and increased temperatures. CO2 concentrations will probably increase to 459-550ppmv by 2050, compared to about 350 at present. CO2 enrichment in the atmosphere is likely to reduce the rate at which plants transpire, resulting in an increase in water use efficiency, although the extent to which this enhances water catchment yields is uncertain (Cicero). Increased temperatures increase the atmospheric demand for water, both evaporation from soils and open water and transpiration from plants. The extent to which precipitation offsets the increased evapo-transpiration demand is highly uncertain in Africa.

According to the IPCC, a reduction in precipitation projected by some GCMs for the Sahel and southern Africa, if accompanied by high inter-annual variability, could be detrimental to the hydrological balance of the continent and disrupt various water-dependent socio-economic activities.  It is likely that some regions will suffer significant decreases in moisture availability, even when the direct effects of CO2 enrichment are included. The risk of drought is likely to increase in such regions as well.

In Sum, the region faces the following potential impacts of climate change:

A 10-20 % decrease in summer rainfall over South Africa's central interior
An increase in the intensity and frequency of floods and droughts
A gradual and linear increase in temperature with rising CO2 levels reaching 1.5 degrees C hotter than present by the year 2050 with an associated increased frequency of higher temperature episodes

The implication for river catchments include

Increased evaporation rates of 5-20 % across the region
A shift in biological communities with grasslands being largely replaced by savannah as a result of increased temperature

Vulnerable Areas

Meeting Water Demand

At present, approximately one third of the world's population live in countries experiencing water stress. It has been forecast that by 2025 as much as two thirds of the world's population could be exposed to water stress. Water resource stresses in many of the poorest countries, already expected to increase, will be exacerbated by climate change. Due to climate change alone, some 66 million extra people will live in countries with water stress and some 170 million people will live in countries, which are extremely stressed (Hadley Centre 1998).

Climate Change is likely to add to economic and political tensions, particularly in regions that already have scarce water resources. Of the 19 countries around the world currently classified as water-stressed, more are in Africa than in any other region, and this number is likely to increase, independent of climate change, as a result of increases in demand resulting from population growth, degradation of watersheds caused by land use change and siltation of river basins (IPCC).

In the SADC region as a whole, water demand is projected to rise at almost 3% annually, equivalent to the region's average annual population growth rate until at least 2020. (SADC/IUCN/SARDC, 1996)[6] However, by current calculations South Africa will suffer water stress[7], Malawi will move into absolute water scarcity and Kenya will be facing the prospect of living beyond the present water barrier. By 2025, Mozambique, Tanzania and Zimbabwe will suffer water stress, Lesotho and South Africa will have moved into absolute water scarcity and Malawi will have joined Kenya living beyond the present water barrier [ADB Harare, 1994 p39]. It is estimated that all of Southern Africa's fresh water resources would be fully used between 2025 and 2030, according to the Orange River Replanning Study (ORRS), an undertaking of the South African Department of Water Affairs and Forestry (DWAF).

Runoff

Runoff in southern Africa spans a great range, from less than 10mm to over 700mm. Interannual variability is greatest in the semi-arid regions (for example, runoff in southern Zimbabwe between 1961 and 1990 varied almost 0 to over 150). South Africa has close to the lowest conversion of rainfall to usable runoff from rivers of all countries in the world. Of the rain that does fall, about  half is caught and stored in dams, while about 8% returns to the sea in rivers and the rest disappears as evaporation, evapotranspiration and infiltration into the ground (Davies and Day 1998). Reynard and Andrews (1995, see also Hulme 1996) predict an overall reduction in annual rainfall in southern Africa and a change in the inter-annual variability of runoff. Model scenarios for 2050, following the standard IPCC methodology (Carter et al. 1994), indicate that runoff would decrease in two of the scenarios (UKTR and CCC) across most of the region. However, runoff increases in the “wet� scenarios, based on the OSU GCM experiment. For the drier scenario, decreases of 10-40% are widespread. With climate change, the variability of runoff increases for the UKTR scenario, which included GCM results on the interannual variability of rainfall.

Evaporation

Southern Africa experiences very high losses of water from evaporation and transpiration, with the result that only a very small proportion of the total rainfall enters the streams or groundwater, where it is available for human consumption. On average 65% of all the rainfall in the region evaporates soon after it has fallen. This value is much lower in relatively cooler and more humid areas in the region, but can get as high as 83% in Namibia, the regions driest country. According to Davies and Day, nowhere in the southern part of the region, except for a few mountains tops in the Drakensberg, and the south-west cape, does rainfall exceed evaporation, while in many parts of the region evaporation outstrips precipitation. In Gauteng, evaporation is twice as great as rainfall and in the lower Orange River valley it reaches a value more than ten times the rainfall.
The 1400km of the Orange River to the Vanderkloof Dam to the river mouth flows through some of the hottest and most arid regions in the world, and is subject to net evaporation rates of up to 3 metres per annum (McKenzie and Craig). The evaporation at Kariba is 20% of flow of the Zambezi at Victoria Falls (112), The average inflow to Pequenos Libombos, Maputo's main reservoir is 7 cm/s, while the average evaporation rates are estimated at 2 cm/s. (SARDC). In 1998, the Namibian Legal Assistance Centre estimated that the amount of water lost annually through evaporation at Epupa would be equivalent to the amount of water, which could supply the needs of the entire city of Windhoek for 42 years.

Relatively small changes in temperature and/or rainfall can have significant effects on evapotranspiration and groundwater recharge. These changes will impact both the total annual flow in rivers and its distribution through the year. In a dry area of Tanzania model results indicate a dramatic 40% decrease in recharge caused by a 15% reduction in annual rainfall, which is further accentuated under degraded conditions to a 58% decrease (Sandström, 1998). Since dry season flow in rivers is maintained by groundwater recharge this has severe implications for freshwater ecosystem integrity in this and similar areas. The increased temperatures will likely lead to increased open water and soil/plant evaporation. Exactly how large this increased evaporative loss will depend on factors such as physiological changes in plant biology, atmospheric circulation and land use patterns. As a rough estimated potential evaporation over Africa may increase by between 5% and 10%. (Cicero 1996)

Irrigation

Currently, there is a strong attraction toward the development of irrigation projects in the region. This is largely the result of the growing incapacity of the region to feed itself (as a result of land degradation and recurrent droughts), as well as the desire of governments in southern Africa to generate foreign currency through the export of cash crops such as tobacco. Irrigation projects are most developed in Zimbabwe (130,000 hectares), Tanzania (25,000 hectares), and Malawi (19,000 hectares). The main irrigated crops are wheat, cotton, maize, tea, and sugar. The irrigation potential is interwoven into the socio- economic fabric of the southern African states. It, therefore, becomes imperative to study present and future trends associated with irrigation practices, that is, the depletion of surface and underground water. In addition, irrigation of large tracts of land may lead to the uprooting of local people from their traditional lands in addition to adverse environmental impacts of reservoir development, including downstream effects.[8] Some studies on the effects of anthropogenically induced climatic changes on irrigation water consumption were conducted by the Food and Agriculture Organisation (FAO), along with the UK's Institute of Hydrology, for the Malibamatsama Basin, 3,240 km 2 in Lesotho (Nemec, 1989; Institute of Hydrology, 1988). Future climate change simulations for this region have been accomplished using a general circulation model with a doubling of CO₂. The model's output indicated a 6 degree C increase in mean monthly temperature, a 4-23% decrease in monthly precipitation from December to May, and a 10-15 % increase in monthly precipitation from June to November. This research suggested that with a doubling of CO₂, changes in meteorological conditions in the basin would lead to a 65 % increase in water demands for irrigation, bringing about the shrinkage of irrigated areas from 37,500 ha at present to 20,000 ha.[9]

Water Health

The incidence of vector borne diseases will be impacted by the predicted increase in temperature and the changing pattern of rainfall.  Climatic changes will create the preferred conditions for disease-carrying mosquitoes and parasites (tsetse flies and ticks). Diseases that thrive in warmer climates such as malaria, cholera and yellow fever are likely to spread. By 2100 it is estimated that there could be an additional 50-80 million cases of malaria each year[10]. The number of people potentially at risk of malaria would increase from 7,819,266 (1996 census data, using Schulze's climate data) to 23,038,318 or 36,300,636 (2010 population, according to the sulphate and no sulphate HADM2 scenarios respectively). Of these, 9,672,597 (2010 population figures) will have lived in previously unaffected areas (where climatic suitability was less than 10%), while 14,495,061 people will have lived in areas where climate change would increase suitable periods from less than 5 months (too short) to 5 months or more.[11] The IPCC has suggested that a drop in water level in dams and rivers could adversely affect the quality of water by increasing the concentrations of sewage waste and industrial effluents, thereby increasing the potential for the outbreak of diseases and reducing the quality and quantity of fresh water available for domestic use.

Agriculture and Food Security

Agriculture accounts for over 30% of gross domestic produce in most of Africa. Most production is dryland, with irrigation covering about 5% of the cropped area. About half of human food consumption is from cereals (maize, wheat, rice, millet and sorghum), a fifth from cassava, while livestock accounts for less than 10% of consumption. Other significant commodities are sugar cane, pulses, groundnuts, cotton, tobacco, coffee and tea. (CICIERO). Presently agriculture contributes one third of total GNP, employs up to 80% of the total labour force and accounts for 20% of foreign exchange earnings. In those states not dominated by mining, agriculture contributes 60% of total foreign exchange earnings. Poverty has risen steadily in the region, with predictions that it will continue at its current rate. Well over half the Southern African rural population lives below the poverty datum line. It is estimated that 4.3 million or 25% of the children at pre- school are malnourished. In some SADC member states, the number of food- insecure people in the region went from 22 million in the early 1980s to 39 million in 1990; an increase from 37% to 46%.

Of the many crops grown in South Africa, maize production contributed 71 percent to the grain production in South Africa during the 1996 season and covers 58 percent of the cropping area.  To meet the increasing food demand, agriculture has to expand by approximately 3 percent annually.  Maize production in South Africa can be divided into two broad regions.  The dry western areas contribute about 60 percent of the maize produced and the wet eastern areas contribute the remaining 40 percent. 

Under the climate scenario that predicts a hotter drier climate, maize production will decrease by approximately 10 to 20 percent.  Crop decreases will be most serious in the more marginal areas although the higher production levels predicted in the east would possibly offset yield decreases in the marginal western regions. Speciality crops grown in specific environmentally favourable areas may also be at risk as both rainfall and temperature effects may cause changes in areas suitable for specialised production.  Some of the negative crop growth effects may be mitigated by the “fertilisation effectâ€? of CO₂ gas on plant physiology, although scientists are currently divided on the scale and sustainability of these benefits.

Large Hydro -Electricity Dams

The World Commission on Dams Final Report highlights the evidence that "all reservoirs - not only hydropower reservoirs - emit GHGs ... in some circumstances the gross emissions can be considerable, and possibly greater than the thermal alternatives". The Commission found that "the emission of greenhouse gases (GHG) from reservoirs due to rotting vegetation and carbon inflows from the catchment is a recently identified ecosystem impact (on climate) of storage dams. A first estimate suggests that the gross emissions from reservoirs may account for between 1% and 28% of the global warming potential of GHG emissions. It also implies that all reservoirs - not only hydropower reservoirs - emit GHGs ... in some circumstances the gross emissions can be considerable, and possibly greater than the thermal alternatives."

The main emission of greenhouse gas associated with large-scale hydro schemes arise for the chain of processes requires to manufacture and construct the generation and transmission equipment. Methane emissions are also likely to occur from the natural degradation of flooded vegetation and soil. Molecule for molecule methane is 20 times more potent at warming the planet than carbon dioxide. There is also some evidence of the release of nitrous oxide from reservoirs, although insufficient data is available at present (IEA). Research now suggests that hydropower reservoirs, especially those in tropical forest areas, can make a significant contribution to global warming, in some cases as much as or even more than fossil fuel burning plants producing an equivalent amount of electricity.  For example: the Balbina Dam built 13 years ago to provide "green", pollution-free electricity; it in fact produces eight times more greenhouse gas than a typical coal-fired power station with a similar generating capacity. The rotting vegetation has generated millions of tonnes of two greenhouse gases Fearnside (1995) calculated that in 1990, reservoirs in Brazil's Amozonia emitted about 0.26 million tons of methane and 37 million tons of carbon dioxide. According to his finding, the Balbina Dam, has a rate of carbon dioxide and methane emissions, from its reservoirs that had 26 times more impact on global warming than the emissions from a coal-fired power station. In French Guiana, the Petit-Saut dam, which powers Europe's Ariane rocket launch site, produces three times as much gas as a coal-burning equivalent. Calculations by Robert Delmas, of the Laboratory of Aerology Observation in Toulouse, the Petit-Saut reservoir has turned it into one of the worst polluters. Per head of population, French Guiana's emissions are three times those of France and greater than those of the US.
Table 2: Methane emissions from hydroelectric reservoirs in Southern Africa

Source Options for Greenhouse gas mitigation under power pooling, South Center for Energy and Environment, Executive Summary; Phase 1 Report -Inventory of emission from the Power Pool Area Shakespeare Maya March 1998 SADC hydro emissions

Hydro Power Generation

In Africa, hydroelectric power is the only significant grid-connected renewable energy source. In many African countries, hydroelectricity's share of total installed electric capacity is quite high. In Côte d'Ivoire, the Democratic Republic of Congo, Ethiopia, Mozambique, and Zambia, the vast majority of on-grid electricity generation comes from hydropower.

South Africa can be classified as a generally dry country, and thus has very little perennial hydropower potential. The current total installed large-scale hydropower generation capacity (larger than 10 MW), including pumped storage schemes, is 2 222 MW. The installed capacity of plants smaller than 10 MW totals some 65 MW.  While in Southern Africa hydro resources supply almost 18% of power generation. Hydropower is distributed quite unevenly in the region with Zaire (DRC) holding the lion's share at 37% of all effective capacity, Zambia with 22% and Zimbabwe and South Africa 10 and 9% respectively. The rest is located in smaller amounts in other member states. Actual installed capacity is led ranging by Zaire with 2523 MW, followed by Mozambique with 2510 MW and South Africa and Zambia with 797MW and 1670 MW respectively.

The region has already felt the effects of drought on river flow and reservoir volumes for Hydropower generation. During the 94/95 droughts in Zimbabwe, Kariba Dam, which produces most of the country's electricity, was running at only 14% capacity. River flows, like rainfall, Zambezi and Kafue Systems have been experiencing a declining trend since 1980 and have continued to exhibit this downward trend. Monthly runoff volumes recorded on Zambezi River at the Victoria Falls station and on Kafue River at the Hook Bridge station show the effect of the drought years on the flow volumes. When compared to the rest of the flow record, 1994/95 stands out as the driest on record on the Zambezi. (Mwasile and Lindunda. 1995) Kariba Reservoir/Lake Between 1981 and 1992, the lake level dropped from 487.5 m above mean sea level (maximum retention level - 488 m) to 475.9 m (minimum retention level - 475.5 m), a drop of about 1 km of water within a decade. The large drop in reservoir level has been due to a gradual decline in rainfall, coupled with the unclear reservoir operation scheme. (Mwasile and Lindunda, 1995) Itezhitezhi/Kafue George Reservoir (ITT) The full reservoir level at ITT guarantees 50% of the country's energy requirements under normal rainfall conditions. However, the ITT dam is a seasonal reservoir and, therefore, its effective management is problematic in the face of erratic rains and absence of operating guidelines or rules.[12] While in Namibia, power utility NAMPOWER, has repeatedly faced water and energy shortages due to the low levels of the Kunene River and has relied heavily on imported electricity from South Africa. In 1997 Namibia was importing close to 1005 of its electricity from South African Utility Eskom. The water flow at that time in Ruacana had been reduced to low as 29.1 cubic centimetre per second. The three turbine hydroelectric plant with a maximum capacity of 239 MW hours was produce close to 33 MWh.

Calculations of the amounts of water available to turn turbines, the maximum flood, which spillways will have to discharge, and the rate at which reservoirs fill with sediment will become increasingly unreliable as global warming continues to take hold.[13] The IPCC response strategies recommended that increased runoff due to climate change could potentially pose a sever threat to the safety of existing dams with design deficiencies, even recommending that design criteria for dams requires a re-evaluation to incorporate the effects of climate change.

Therefore, caution needs to be applied to new hydro generation options as climate change likely to increase the frequency of extreme events and thereby reduce hydropower output, increase flooding and reduce dam safety. In planning for hydro electric generation, consideration would also have to be given to potential adverse effects of climate change (social, environmental and economic), such as inundation of agricultural lands, forested lands, wetlands, downstream impacts on navigation, flood control, water supplies and effects on aquatics resources and recreation.[14] The WCD states:

"Normal variations in weather and river flows dictates that virtually all hydroelectric projects will have year to year fluctuations in output, whether climate change will affect this remains to be seen. There is a risk that a changing climate will modify the hydrological basis on which many flood control dams were designed. This raises concerns about the physical adequacy of many dams to perform their flood management functions, as well as the adequacy of spillways to handle much higher flood control volumes likely in a changed climate. Climate change has introduced another level of uncertainty about changing flows within the life span of most dams. The safety of large dams is affected by changes in the magnitude or frequency of extreme precipitation evens ...There is concern, therefore, about whether existing spillways can evacuate
such floods in the future."

Biodiversity, Wetlands and Tourism

Inland water ecosystems are among the world's most fragile, scarce and threatened ecosystems. Probably more than any other area of biodiversity on the planet, inland waters are the focus of conflicting human uses and resultant pressures. Yet they are vital for the maintenance of the economic, social and environment health of human society The majority of inland water ecosystems are interlinked by the hydrological cycle and also represent important pathways for materials, including nutrients and contaminants, between atmosphere, land, the subsurface and the oceans.[15] Costanza et al. (1997) estimated the total global value of services provided by coastal areas and wetland ecosystems to be 15.5 trillion USD y^-1 being 46% of the total value of services that global ecosystems are estimated to provide.

It is generally understood, however, that increases in temperature, sea level rise, and changes in precipitation will degrade those benefits and services. Wetlands will be affected in different ways by shifts in the hydrological cycle. These include changes in precipitation, evaporation, transpiration, runoff and groundwater recharge and flow. These changes will affect both surface and groundwater systems and impact wetland requirements, domestic water supply, irrigation, hydropower generation, industrial use, navigation and water based tourism.

Freshwater Responses to Climate Change

Adaptation to climate change is a broad category of actions that attempt to reduce the vulnerability caused by climate change:

Adaptability refers to the degree to which adjustments are possible in practices, processes, or structures of systems to projected or actual changes of climate. Adaptation can be spontaneous or planned, and can be carried out in response to or in anticipation of changes in conditions (IPCC,1995).

Adaptation is concerned with responses to both the adverse and positive effects of climate change. Adaptation is now widely appreciated to be a dynamic process and not a one step response to a single impact. Adaptation, particularly, in the water and energy sectors, along with mitigation, must be considered urgently as part of an integrated regional response to climate vulnerability and change.  Preparing for climatic hazards will require reducing vulnerability, improving the efficiency of water use, developing monitoring capabilities and contingency plans, and utilising climatic forecasts. New supplies must be developed and existing supplies used more efficiently. Long-term management strategies should include: regulations and technologies for directly controlling land and water use, incentives and taxes for indirectly affecting behaviour, the construction of new reservoirs and pipelines to boost supplies, and improvements in water-management operations and institutions. Other adaptation measures can include removing levies to maintain flood plains, protecting waterside vegetation, restoring river channels to their natural form, and reducing water pollution. Enhanced preparedness is thus a direct response to climate change as well as contributing to current development objectives
 
The United Nations Framework Convention on Climate Change (UNFCCC)

The objective of the United Nations Framework Convention on Climate Change (UNFCCC) is to protect the global climate system from negative anthropogenic interference caused by increasing accumulation of GHG concentrations in the atmosphere. The FCCC is primarily concerned with GHG abatement and the stabilization of GHG emissions, but it nonetheless explicitly addresses the issue of adaptation to effects of climate change.

The ultimate objective of this Convention and any related legal instruments that the Conference of the Parties may adopt is to achieve, in accordance with the relevant provisions of the Convention, stabilisation of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.

The convention states that “ Parties " should take precautionary measure to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects. Where there are threats of serious or irreversible damage, lack of full scientific certainty should not be used as a reason for postponing such measure" (Article 3.3)

Pursuant to Article 3.3 of the FCCC:

“ The Parties should take precautionary measures to anticipate, prevent or minimize the causes of climate change and mitigate its adverse effects…[P]olicies and measures should take into account different socio-economic contexts, be comprehensive, cover all relevant sources, sinks and reservoirs of greenhouse gases and adaptation, and comprise all economic sectors.�

Following Article 4.1 (b), all parties to the FCCC commit themselves to:

'Formulate, implement, publish and regularly update national and, where appropriate, regional programmes containing… measures to facilitate adequate adaptation to climate change'.

And, more specifically, following Article 4.1 (e) and (f) all parties to the FCCC shall:

“ Cooperate in preparing for adaptation to the impacts of climate change; develop and elaborate appropriate and integrated plans for coastal zone management, water resources and agriculture, and for the protection and rehabilitation of areas, particularly in Africa, affected by drought and desertification, as well as floods.�

“Take climate change considerations into account, to the extent feasible, in their relevant social, economic and environmental policies and actions, and employ appropriate methods, for example impact assessments, formulated and determined nationally, with a view to minimising adverse effects on the economy, on public health and on the quality of the environment, of projects or measures undertaken by them to mitigate or adapt to climate change.�

Pursuant to Article 4.4, moreover, the industrialized countries have a special obligation to assist developing countries that are particularly vulnerable to adverse climate effects:

“ The developed country Parties and other developed Parties included in Annex II shall also assist the developing country Parties that are particularly vulnerable to the adverse effects of climate change in meeting the costs of adaptation to those adverse effects.�

Finally Article 4.8 Parties commitment to give full consideration to what actions are necessary under the Convention, including actions related to funding, insurance and the transfer of technology, to meet the specific needs and concerns of developing country Parties arising from the adverse effects of climate change and/or the impact of the implementation of response measures, especially on:

(c)....Countries with arid and semi-arid areas, forested areas and areas liable to forest decay.
(d)....Countries with areas prone to natural disasters.
(e)....Countries with areas liable to drought and desertification.
(g)....Countries with areas with fragile ecosystems, including mountainous ecosystems.
Water Resource Strategies to Adapt to Climate Change

Adapted from Benioff (1996), Riebsame (1995), Kaczmarek and Napiorkowski (1996), Golubtsov et al. (1996), Campos et al. (1996), Smith and Lenart (1996), Stakhiv (1996).

Implementing Agenda 21: Freshwater and Climate Change

Conclusion

The degree to which societies and institutions can adapt to climate change will depend on their ability to manage water resource supply and demand. Water resource management has traditionally focused on the supply side management. Only recently has demand side water management become a viable alternative strategy. Societies that are able to implement both resource supply side and demand side management strategies are likely to be more adaptive to climate change than those societies that are unable to do so. The ability to adapt to climate change also depends much on the institutional capacity to develop and implement such strategies, and is largely a function of the socio-economic, political, legal and institutional setting in which such institutions operate. If South Africa and the countries of the region invest, now, in maintaining and strengthening their capacities to integrate and manage uncertainty, they are likely to adapt to climate changes.

The goals of sustainable water management and conservation are unlikely to be achieved without taking climate change into account. Information about the consequences of climate change on specific water resources and river basins is sorely needed to allow water resource planners and managers to integrate changes in climate into their planning and management efforts. It is generally understood, though, that removing the existing pressures on water resources and improving their resiliency is the most effective method of cope with the adverse effects of climate change. Water resources play an important role in the global carbon cycle and wetlands in particular are a significant storehouse of carbon. However when these resources (wetlands) are converted, they emit large quantities of carbon dioxide and other greenhouse gases. Conserving, maintaining, or rehabilitating freshwater ecosystems is therefore a viable element to an overall climate change mitigation strategy.

Therefore, the immediate challenges for South Africa include:

To understand and quantify the threat of the impact of climate change on freshwater resources,
To facilitate the implementation of effective national countermeasures to address the vulnerability of freshwater resources to climate change, and
To study the potential impacts of climate change on areas prone to droughts and floods and implement remedial measures

Richard Sherman
Research and Policy Coordinator,
Sustainable Energy and Climate Change Partnership,
Earthlife Africa Johannesburg
P. O. Box 11383, Johannesburg, 2000
Tel: 011 339 3662 Fax: 011 339 3270
Cell: 082 464 1742
Email: [email protected]