An Early Warning System (EWS) is a set of coordinated procedures through which information on foreseeable hazards is collected and processed to warn of the possible occurrence of a natural phenomenon that could cause disasters. These systems are acquiring more importance in view of increased climate variability and the ability to implement them has become fundamental for improving capacity to adapt to climate change.
There are two types of EWS:
- Centralised systems implemented by national government bodies. The ministry of defence or another appropriate government entity is responsible for implementing hazard warning and response activities.
- Decentralised community systems, usually operated by a network of volunteers employing simple equipment to monitor meteorological conditions and operate radio communication networks.
Operators of decentralised community meteorological stations report the information to a local forecasting centre where the data is analysed and then communicated back to the community network. The demand for community-led systems is increasing due to lower operational costs and the need for local forecasting and monitoring of climate variability and potential disasters.
The following are the main implementation stages of a decentralised community system:
- Establishing an organising committee (leaders of the community and civil society, NGOs, representatives of local authorities and the private sector)
- Creating and analysing information: building and installing measuring instruments, carrying out forecasts
- Producing a participatory emergency and contingency plan
- Implementing a communication system: early warnings, dissemination of prevention, mitigation and adaptation measures.
Increased frequency and intensity of extreme weather events, prolonged drought and processes of desertification, longer periods of heavy rainfall and increased risk of flooding are just some of the impacts of climate change affecting the world’s poorest populations (IPCC WG II, 2007). EWS technology designed as a climate change adaptation strategy must therefore be capable of forecasting a number of climatic events that correspond to different time scales:
- Three to four months of advance warning of a drought
- Two to three weeks of advance warning of freezing weather conditions and monsoons
- A few hours of advance warning of torrential rain, hail and floods.
This technology contributes to the climate change adaptation and risk reduction process by improving the capacity of communities to forecast, prepare for and respond to extreme weather events and thereby minimise damage to infrastructure and social and economic impacts, such as loss of livelihoods.
Development benefits and other co-benefits provided by this technology include:
- Introduction of hazard-related and disaster management concepts into community-level planning processes
- Exchange of information of a social or legal nature, in addition to climatic information, through the established communication network
- Facilitation of decision-making in political organisations
- Creation and improvement of a structure that incorporates different stakeholders involved in drawing up specific action plans.
The majority of EWSs were established to prevent or reduce the impacts of climate-related disasters (such as floods and hurricanes). By comparison, the capability of these systems to forecast droughts, extreme colds and Indian summers has been less effective. Droughts are particularly distinguishable from other extreme weather events in that they begin slowly and gradually and are less ‘obvious’ at the outset. In addition, drought can last extended periods of time and affect extensive areas. Given these complexities, EWS systems should be complemented with historical data on droughts, along with available climatological, hydrological, physical, biological and socioeconomic statistics. Only by combining this data can the complex causes of droughts be better understood and different scenarios modelled with the aim of developing prognoses (such as the probable start date of the rainy season or possible variations in rainy and dry seasons) to be disseminated via appropriate communication channels (Damman, 2008).
The initial implementation costs of a decentralised system comprised of ten local governments in one micro-water basin are estimated at US$ 52,000 and annual operating costs are estimated at US$ 25,000, as detailed below in Table 1.
Table 1: Indicative Costs for Implementation and Maintenance of Community Early Warning System
|Awareness-raising campaign including the involvement of authorities, institutions and the population.||10,000||Workshops, printed material and radio broadcasts|
|Installation of a local weather station||10||5,000||1 station/district|
|Installation of limnimetric scales||10||2,000||1 scale/district|
|Creation and analysis of information: forecasting protocols||Study||10,000||1 study for all ten districts|
|Participatory production of the emergency and contingency plan||Study||10,000||1 study for all ten districts, including emergency drills|
|Implementation of a communication system: warning notices, mechanisms to disseminate prevention, mitigation and adaptation measures||Overall||5,000||Design of news bulletin and radio announcement formats and models, broadcasting via local networks|
|Training for local EWS operators and promoters||Overall||10,000||Around 20 people per district. Includes the production of training material|
|Annual operating costs|
|Equipment maintenance||1,000||The sum includes basic maintenance of weather stations and limnimetric scales.|
|Radio broadcasts||6,000||$50/month per district|
|Dissemination of printed material||6,000||$50/month per district|
|Communications||12,000||$100/month per district|
Source: Damman, 2008
The obstacles that could prevent the successful implementation and use of the technology are related to a number of factors. These include the population’s lack of confidence in a new and unfamiliar system, problems with the dissemination of information to rural populations living in remote areas and the financial and management sustainability of the system.
Suggestions for overcoming these barriers, which have been tested in cases applied in Peru (Damman, 2008) include:
- Undertake a comprehensive awareness-raising and education plan amongst the population and participating institutions
- Ensure participation of the population and local institutions in the planning and implementation processes
- Incorporate local methods for disseminating information into the communication strategy
- Develop a network of local promoters linked to grassroots organisations for dissemination of information
- Develop sustainability and maintenance mechanisms, linking the EWS with local governments.
The decentralised community system provides an opportunity for building awareness on climate change and disaster risk prevention approaches. It also provides opportunities for building capacity in decentralisation, participatory planning and budgeting processes whereby previously centralised roles are transferred to local governments and community stakeholders.
Damman, G. (Ed.) (2008) Sistemas de información y alerta temprana para enfrentar al cambio climático: propuesta de adaptación tecnológica en respuesta al cambio climático en Piura, Apurímac y Cajamarca, Soluciones Prácticas-ITDG, Lima, Peru. P.166.
IPCC WGII (2007) - Impacts, Adaptation and Vulnerability, Contribution of Working Group II to the Fourth Assessment Report of the IPCC on Climate Change, Cambridge University Press, Cambridge, UK, 2007. M.L. Parry, O.F. Canziani, J.P. Palutikof, P.J. van der Linden and C.E. Hanson (eds) Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.