(will be published in IFFN No. 23 – December 2000, p. 3)
Fire is a dominant disturbance factor in almost all vegetation zones throughout the world. In many ecosystems fire is an essential and ecologically significant force – organising physical and biological attributes, shaping landscape diversity, and influencing energy flows and biogeochemical cycles, particularly the global carbon cycle. In addition, the use of fire as a land-management tool is deeply embedded in the culture and traditions of many societies, particularly in agriculture and pastoralism in the developing world.
Conversely, in some ecosystems fire is an unnatural process that often leads to vegetation destruction and long-term site degradation, yet these regions, particularly in the humid tropics, are becoming increasingly vulnerable to fire due to growing population, economic, and land use pressures. Even in regions where fire is natural, e.g. the northern circumpolar boreal zone, more frequent severe fire weather conditions have created recurrent major fire problems in recent years. Extreme wildfire events are increasing throughout the world, with significant impacts on economies, and human health and safety comparable to those associated with other natural disasters, such as earthquakes, floods, droughts and volcanic eruptions. In many countries, rapidly changing social, economic and environmental conditions suggest that marked changes in fire regimes can be expected, with unknown local, regional, and global consequences.
Fires in forests and other vegetation produce gaseous and particle emissions that have impacts on the composition and functioning of the global atmosphere. These emissions interact with those from fossil-fuel burning and other technological sources which are the major cause for anthropogenic climate forcing. Fire risk modelling in expected climate change scenarios indicates that within a relatively short period, the next three to four decades, the destructiveness of human-caused and natural wildfires will increase. Fire management strategies which include preparedness and early warning cannot be generalized due to the multidirectional and -dimensional effects of fire in the different vegetation zones and ecosystems and the manifold cultural, social, and economic factors involved.
Global fire occurrence
Reliable statistical data on occurrence of wildfires and land-use fires, areas burned and losses are available for only a limited number of nations and regions. Within the northern hemisphere the most complete dataset on forest fires is periodically collected and published for the member states of the Economic Commission for Europe (ECE). It includes all Western and Eastern European countries, countries of the former Soviet Union, the U.S.A. and Canada. Since the dataset is restricted to forest fires, it does not include land-use fires which are also a major source of fire-caused smoke pollution.
Other countries from outside the ECE/EU region report fire statistics in the pages of International Forest Fire News and other published and non-published reports. These statistical data are currently updated at the Global Fire Monitoring Center (GFMC) (see below).
A global dataset of fire activities has been developed on the basis of active fires detected by the NOAA AVHRR sensor. This dataset provides the temporal and spatial distribution of vegetation fires throughout the year. However, it does not yet provide a quantitative database in terms of area burned, vegetative matter combusted, and gas and particle emissions generated. Spaceborne sensors have been used in a large number of case studies to determine land areas affected and emissions produced by fires. Thus, potential tools for a quantitative inventory of fire effects using spaceborne sensors are available (see contribution by Hoffmann, this volume).
Main types of vegetation fires
Wildfires (uncontrolled fires) are common in all vegetation zones. They are mostly caused by negligence and are often associated with escaped land-use fires. Both wildfires and land-use fires can directly or indirectly cause immediate damages or have long-term environmental or humanitarian consequences. Despite the fact that many ecosystems are well adapted to fire and land-use fires often follow traditional and established practices, there is an increasing tendency of fire events causing conflicts with the needs of the rapidly growing populations of the developing countries and at the interface with vulnerable structures of industrialized societies.
Wildfires (uncontrolled fires) in forests
In the temperate and northern boreal forests wildfires are occurring regularly during the dry northern summers. In North America and Eurasia between 5 and 20 million hectares (ha) are burned annually. In the less populated high latitudes the ignition sources are dominated by lightning, while in more frequently populated regions humans become the dominating fire cause. In the Mediterranean region an average of ca. 0.6 million ha of forest and other land is burned annually.
The equatorial rain forests are usually too moist to allow the propagation of wildfires. However, extreme droughts in association with forest exploitation periodically create conditions of flammability, fuel availability and fire spread in the equatorial rain forests. Such events regularly occur in the forests of tropical South Asia in association with cyclic climate variability caused by the El Niño-Southern Oscillation (ENSO) phenomenon. Some examples of large-scale (catastrophic) fire events are given further below.
The largest areas affected by uncontrolled wildfires in tropical forests are in the seasonal forest biomes (deciduous and semi-deciduous forests, sometimes also referred to as “monsoon” forests). Here, the fires are burning in short return intervals of 1 to 3 years. The tropical submontane coniferous forests (pine forests) are also subjected to regular fires.
Wildfires in tropical grass, brush and tree savannas
Tropical savannas cover an area of ca. 2.3-2.6 billion ha worldwide. Savannas typically consist of a more or less continuous layer of grass with interspersed trees and shrubs. There are numerous transition types between savannas and open forests. The surface fuels in these ecosystems which are dominated by grasses and leaves which are shed during the dry season, are burned periodically at intervals which may range from one to four years. This fire frequency has becoming increasing in some regions as a result of increasing population and more intensive use of rangeland. The area of savannas potentially subjected to fire each year is up to several hundred millions of hectares. As a result, savanna burning releases about three times as much gas and particle emissions to the atmosphere as deforestation burning. It is estimated that more than 3 billion tons of vegetative matter are burned in tropical savannas annually.
Conversion of forest and brushland to plantations, agricultural and pastoral systems
Two types of forest clearing for agricultural use are common, predominantly in the tropics: shifting agriculture, where the land is allowed to return to forest vegetation after a relatively short period of use, and permanent removal of forest to be converted to grazing or crop lands. In both instances, the clearing and burning follows initially the same pattern: trees are felled at the end of the wet season. After extraction of marketable and otherwise usable trees, the vegetation is left for some time to dry out in order to obtain better burning efficiency. In shifting agriculture, which is practised by several hundred million people worldwide, the cleared areas are used for agriculture for a few years until yields decline, and then are abandoned and new areas cleared. The generally observed shortening of shifting agriculture cycles is increasingly associated with site degradation and makes this traditional land-use technique one of the leading causes of global tropical deforestation.
The conversion of primary or secondary forest into permanent agriculture and grazing land, including tree plantations, is driven by expanding human populations that require additional food and living space, but also by large-scale resettlement programmes and land speculation.
The net amount of plant biomass which is combusted in the process of vegetation clearing is somewhat in the range of 1 to 2 billion metric tons.
Burning of agricultural residues, control of bush and weeds, nutrient cycling on grazing and croplands
A substantial amount of agricultural residues, e.g. straw and stalks, is disposed off by burning. The magnitude of this practice is extremely difficult to quantify because of its distributed nature. No statistics are available, mostly because no material of direct economic value is involved. It has been estimated that between 800 and 1,200 million tons of agricultural residuals are burned annually, making this practice a major source of atmospheric pollution, mainly in the tropics.
By tradition fire is also a common practice to control bush and weed encroachment and grazing and crop lands.
Recent major fire episodes and losses
Comprehensive reports with final data on losses caused by forest and other vegetation fires (wildland fires), including impacts on human health, are only occasionally available. The main reason for the lack of reliable data is that the majority of both the benefits and losses from wildland fires involve intangible non-use values or non-market outputs which do not have a common base for comparison, i.e. biodiversity, ecosystem functioning, erosion, etc. Market values such as loss of timber or tourism activity have been calculated in some cases:
The large wildfires in Borneo during the ENSO drought of 1982-83 burned more than 5 million hectares of forest and agricultural lands. In East Kalimantan a fire damage inventory revealed total losses of ca. US$ 9 billion
First assessment of damages caused by the fire episode of 1997-98 in Indonesia on ca. 8-9 million ha: losses of ca. US$ 10 billion; aprox. 40 million people in SE Asia affected by smoke in various degrees (by increased morbidity and mortality; long-term health effects); more than 250 fatalities due to aircraft and maritime accidents.
The fires burning in Mexico during the 1998 episode forced the local government to shut down industrial production in order to decrease additional industrial pollution during the fire-generated smog. Daily production losses were ca $US 8 million.
Australia’s Ash Wednesday Fires of 1983:
human death toll: 75
burned homes: 2539
burned domestic livestock: nearly 300,000
Extended forest and savanna fires in Côte d’Ivoire 1982-83:
human death toll: more than 100
burned land area: 12 million ha
burned coffee plantations: 40,000 ha
burned cocoa plantations: 60,000 ha
Forest fires in the Northeast of the People’s Republic of China during the 1987 drought:
human death toll: 221
burned forest: 1.3 million ha
homeless population: 50,000
average annual human fatalities 1950-98 (all China): 92 dead, 551 wounded
Same fire episode in the Soviet Union during the 1987 drought:
burned forest: 14.5 million ha
burned forest 1998: 7.1 million ha
Mongolia steppe and forest fires 1996-97:
burned area 1996: 10.7 million ha
human death toll: 25
burned domestic animals: 7000
burned stables/houses: 576/210
damage assessment: US$2 billion
burned area 1997: 12.4 million ha
Smoke pollution generated by wildland fires occasionally creates situations during which public health and local economies are affected seriously. The smoke pollution in Indonesia and its neighbouring countries is one of the well known cases described by A. Heil (this volume). The WHO Health Guidelines on Vegetation Fire Events deal with this problem (http://www.who.int/peh/air/vegetation_fires/htm).
Hazard assessment as the basis of risk analysis
Early warning systems for fire and smoke management for local, regional, and global application require early warning information at various levels. Information on current weather and vegetation dryness conditions provides the starting point of any predictive assessment. From this information the risk of wildfire starts and prediction of the possibility of current fire behaviour and fire impacts can be derived. Short- to long-range fire weather forecasts allow the assessment of fire risk and severity within the forecasting period. Advanced spaceborne remote sensing technologies allow fire weather forecasts and vegetation dryness assessment covering large areas (local to global), at economic levels and with accuracy which otherwise cannot be met by ground-based collection and dissemination of information. Remote sensing provides also capabilities for detecting new wildfire starts, monitoring ongoing active wildfires, and, in conjunction with fire-weather forecasts, providing an early warning tool for escalating, extreme wildfire events. See the contributions by G.Buchholz and D.Weidemann, and by A.Hoffmann (this volume).
Fire prevention and control: The role of communities
At global scale the majority (approximately >90%) of all wildfires start in the context of land use. Negligence, ignorance, and lack of ability (lack of technologies and training) to control escaping fires are the main responsible causative agents. Thus, fires represent a natural hazard which cannot only be predicted and controlled but also prevented. Fire prevention, however, must address different sectors of the society. Public policies which determine land use, resources protection, or welfare of rural populations, create the main underlying conditions of wildfire occurrence. Individuals and groups which use fire in forests, agriculture and pastoralism are the main cause for disastrous wildfires. At the same time they are potentially threatened by wildfire.
Public education programmes for fire prevention address target groups which vary from country to country. Negligent urban people (tourists) which often are main fire starters in the industrial countries, must be targeted by specific public awareness campaigns using mass media or specific advertisements, e.g. in recreation areas, national parks etc. Education programmes for school children involve different media to transport messages of environmental protection including forest fire prevention.
Most important in wildfire prevention is the involvement of rural communities. Experience in community-based fire management shows that incentive programmes create conditions of a positive atmosphere of collaboration and trust between land users and authorities. See the contribution by H.Abberger (this volume).
Towards global programs in fire research and cooperation in fire management
Despite this high profile, current estimates of the extent and impact of vegetation fires globally are far from complete. Several hundred million hectares of forest and other vegetation burn annually throughout the world; however, a large percentage of these fires are not monitored or documented. Clearly, informed policy decision-making and emergency responses, including humanitarian assistance, require the timely quantification of fire activity and impacts nationally, regionally and globally. Primary policy considerations relate to concerns about the regional and global impacts of excessive and uncontrolled burning, broad-scale trends over time, and the options for instituting protocols that will lead to more efficient control. Key policy questions involve determining whether fire is a sufficiently serious problem to require action and, if so, what factors govern its incidence and impacts, and what are the relative costs and benefits of different options for reducing adverse impacts?
In order to answer the numerous open questions the Global Fire Monitoring Center (GFMC) was established in 1998. It is designed as an information and monitoring facility which national and international agencies involved in land-use planning, fire and other disaster management, scientists and policy makers can utilise for planning and decision making.
The GFMC is hosted by the Fire Ecology and Biomass Burning Research Group of the Max Planck Institute of Chemistry, Biogeochemistry Department, Germany, which also serves as a co-ordination unit of the Biomass Burning Experiment (BIBEX) of the International Geosphere-Biosphere Programme (IGBP), International Global Atmospheric Chemistry (IGAC) Project, and the UN-FAO/ECE/ILO Team of Specialists on Forest Fire. The GMFC was initially sponsored by the Government of Germany, Ministry of Foreign Affairs, Office for the Co-ordination of Humanitarian Affairs, as a German contribution to the UN International Decade of Natural Disaster Reduction (IDNDR). The creation of the GFMC in 1998 was in line with the policies of several international agencies and institutions which developed close partnerships, notably with
the UN International Decade of Natural Disaster Reduction (IDNDR) and its successor arrangement, the International Strategy for Disaster Reduction (ISDR)
the World Conservation Union (IUCN)
the Deutsche Gesellschaft für Technische Zusammenarbeit mbH (GTZ)
the United Nations Economic Commission for Europe (ECE)
UN International Search and Rescue Advisory Group (INSARAG), Fire Group
the International Tropical Timber Organization (ITTO)
the World Health Organization (WHO)
the United Nations Educational and Scientific Organization (UNESCO)
the World Bank, Disaster Management Facility (DMF) and its associated ProVention Consortium on Natural and Technological Catastrophes and the World Institute for Disaster Risk Management (DRM)
the Technical Assistance to the Commonwealth of Independent States (TACIS) programme in Russia
the U.S. Bureau of Land Management (BLM)
After the end of the IDNDR (1990-2000) the GFMC continues to support the IDNDR successor arrangement: the International Strategy for Disaster Reduction (ISDR) and the work of the ISDR Inter-Agency Task Force (IATF) which operates under the direct authority of the Under-Secretary General for Humanitarian Affairs of the United Nations. In October 2000 the IATF Working Group Wildland Fire was established at the 2nd IATF meeting which will be coordinated by the partners IUCN and GFMC (see editorial of this issue of IFFN and News from the ISDR).
The GFMC fire documentation, information and monitoring system is accessible through the Internet: <http://www.uni-freiburg.de/fireglobe/>
The Fire Ecology and Biomass Burning Research Group and the GFMC are located in the converted Old Airport Tower at the Airport Campus, Freiburg University (Germany). The expertise of the institute goes back to the mid-1970s when global scientific research and development work in the field of fire ecology, cultural history and socio-economics of vegetation fires, science transfer into operational management systems and policy development began at Freiburg University. In the same time period the Max Planck Institute for Chemistry, located in Mainz (Germany) took the lead in investigating the role of vegetation fires in global biogeochemical cycles and atmospheric chemistry. The two institutions merged in 1990 and created the first interdisciplinary global fire research facility. The information on global fire research programmes of IGAC-BIBEX is accessible through the GFMC website. Since 1999 the GFMC is part of the German Research Network for Natural Disasters <http://www.dfnk.gfz-potsdam.de> and is member and closely co-operates with the national German Committee for Disaster Reduction.
The Fire Ecology Research Group/GFMC has provided advisory services for a broad range of bi- and multilateral scientific, technical fire management and fire policy development programmes in all continents. Cooperation with GTZ projects were implemented in Brazil (University of Paraná, Curitiba, 1980-82), Indonesia (Mulawarman University and IFFM, 1987-ongoing), Algeria (Projet Pilote de Développement Forestier du massif de Collo, 1992), Argentina (CIEFAP, Esquel, 1991-97), Sudan (Jebel Marra Forest Circle, 1991); see also Waldinfo No. 13 (1994).