29 November 2007
Climate variability, a common factor of desertification and climate change
By Mélanie Requier-Desjardins, Observatoire du Sahara et du Sahel
Climate change refers to significant long-term modification of the climate, due mainly to human activities. The desertification phenomenon degrades land and soil in dry areas, according to various factors, among which are a combination of climate variations and human activity. This definition indicates that if all other factors remain constant, climate change will increase the risks of desertification in dry areas.
The main difference between climate change and desertification is the time scale on which they occur. Climate change takes place over much longer periods than desertification.
The impact of climate change in dry areas in Africa
The regions vulnerable to desertification risks are characterised by a ‘natural’ acute climate variability, which refers more specifically to fluctuating rainfall. Within drylands, climate change increases rainfall variability and intensity, which accelerates the degradation of vegetation cover and hence erosion, thus accelerating desertification mechanisms.
In the Sahel strip to the south of the Sahara, an observation of rainfall minima and maxima over a few decades indicates that since the 1970s, abundance peaks and scarcity dips are more marked than during the previous periods. The start of the winter season is delayed, which makes the stop-gap period in between harvests longer. During a given season, the temporal distribution of rain leads to an increased frequency of drought and flood pockets.
For regions to the North of the Sahara desert, the issue of the impact of climate change is posed in different terms. Though the region is characterised by low rainfall, which varies between countries and years and for the beginning of the next century, the Intergovernmental Panel on Climate Change (IPCC) foresees a serious trend of increasing aridity.
However, the rural development of these regions is characterised by an increasing disconnection of farming activities, agriculture and livestock breeding from rainfall. Irrigated agriculture of the oasis type, which is traditionally the predominant form, is evolving towards the exploitation of transnational underground aquifers. Livestock are increasingly being fed on industrial sub-products from agriculture.
Thus, the problems in this region have, in general, more to do with the management of water resources and will no doubt increase with climate change. Other negative consequences could be the impact of climate change on the marine and coastal environments due to a rise in the sea level.
Vulnerability and adaptation at the core of both phenomena
Whether causing extreme events or inadequate rainfall, climate change goes beyond posing risks to the environment. The economy of rural African populations is mainly based on harnessing natural resources, in particular water, land and their products and services. Many dry areas are located in the least developed countries (LDCs) that are already suffering from desertification. In fact, the general trend towards rising climate risk and diminishing natural and social environments’ capacities is an indication of increasing ecological and social vulnerability. Climate change and desertification are both defined by increased vulnerability
The concept of adaptation refers to any adjustment in natural or human systems in order to deal with the actual or predicted effects of climate change. Adaptation methods vary from one society and context to another but they also depend on a population’s resources and the level of development of the country in question.
UNEP and IPCC distinguish between two forms of adaptation for the purpose of reducing vulnerability to climate variability and change. Anticipatory adaptation is implemented before the initial impact occurs. It requires a risk knowledge system and information systems, particularly efficient environmental1 information systems. Reactive adaptation, however, is designed and implemented in response to initial impacts. This could take the shape, for example, of a major change in cropping practices2.
Considered over the very short term, reactive adaptation may, furthermore, aggravate desertification when, to deal with periods of drought and famine, populations start consuming immature subjects in their environment thus endangering the reproduction of species.
Adaptation, traditional knowledge and natural resource management
In regions that are naturally subject to significant climate variability, populations have developed specific adaptation techniques over the centuries. In the Sahel, since the major droughts of the 1970s and in a context of the liberalisation of economies, we have observed the emergence of new forms of adaptation and the sometimes late recognition of the relevance of older techniques. A bundle of spontaneous rural practices and behaviours appear as adaptation mechanisms, which underline that adaptation is essentially a social phenomenon. There is a dearth of long-term agricultural and livestock breeding policies that would enable these practices to be integrated, in a sustainable way, in national development strategies.
Conclusion and recommendations
There are several possibilities to ensure that efforts undertaken for adaptation and the fight against desertification converge.
Better identification of adaptation mechanisms and better evaluation of vulnerability.
The sectors that are the most sensitive to climate variability and change in Africa are also those which are the most sensitive to desertification:
The risks are not only climatic and ecological; conflicts over water rights, poverty and migration may also increase, with increasingly perceptible consequences, on a global scale.
The importance of knowledge management and environmental information
Information is vital for adaptation and climate and environment monitoring is indispensable for forecasting risks. However, the results of the most advanced research must be made accessible and understandable both to national structures in charge of managing and preventing crises and as well as to final users (populations, civil society, NGOs). This work on translating and distributing information and scientific knowledge requires specific pedagogical skills. Exchanges of experience, for instance between the North and the South of the Sahara, should also be promoted in this framework.
In order to ensure better management of available information, it is essential to develop a base of regional knowledge of the crucial stakes involved in degradation of natural resources (water, soils, climate). Such a base will only be viable if it is regularly fed on a national level, via all of the initiatives undertaken in favour of the environment and socio-economic development. It would require setting up or reinforcing national systems for observing and evaluating natural resources. This can be done through a user-friendly model for gathering data and for making and managing databases.
It would also be useful to specify how monitoring of desertification feeds into climate monitoring. Thus, setting up or reinforcing national information systems for environmental issues would make it possible to improve implementation of multilateral environmental agreements.
The need for regional development and more dialogue
Regional cooperation is important to the extent that many African countries share natural resources (river basins, aquifers, protected reserves, etc.), belong to common institutions and are subject to the same environmental concerns, including degradation of land and climate variability and change. It is important to emphasise the reinforcing of regional networks that may be made possible through African organisations on a sub-regional, regional or even international level. Such a regional platform should also involve sub-regional authorities, specialised sub-regional technical organisations working together with bilateral cooperation organisations, multilateral organisations with databases on Africa, as well as environmental NGOs.
Adaptation should thus offer an opportunity to reinforce existing instruments and encourage the introduction of efficient procedures for the collection and processing of data that indicates clearly where the information comes from. This should not take the form of a new programme or plan that would duplicate those that have already been developed by the affected countries, and which would run into the same implementation obstacles encountered by previous programmes.
Devising strategies to adapt to climate variability and changes should rather be a process that reinforces, supports, stimulates, and emphasises the different environmental governance principles defined by the concerned countries and by the actions envisaged as part of the fight against desertification, or the conservation of biodiversity; actions that have not yet been effectively implemented.
On the international level, it will be a good idea to redefine the framework for reinforcing relations between UNCCD and UNFCCC, in particular through decisions to be taken on adaptation.