Contents - Previous - Next

Chapter 4 Wood energy and environmental security

Health aspects
Climate and atmosphere
Wood energy and land reclamation
Biodiversity dividends

The UN Conference on Environment and Development (UNCED) held in June 1992 in Rio de Janeiro, Brazil, was the largest international conference ever convened. It gave rise to a range of agreements, declarations and guidelines which represent an extremely broad intergovernmental consensus on ways to reconcile poverty relief and economic growth with environmental security in the near and more distant future.

UNCED's conclusions on this score were summed up in Agenda 21, a digest of agreed sustainable development targets for the twenty-first century. Several chapters relate to wood energy in a general way and more specific mentions appear in the texts of the Rio agreements on Climate Change and Biodiversity and in Forest Principles, a set of guidelines for sustainable forestry practice worldwide.

What do these texts signal in terms of specific objectives and mandates for wood energy development in relation to pressing environmental issues and concerns?

Chapter 14 of Agenda 21 recommends that rural people should start a process of 'environmentally sound energy transition' away from 'unsustainable energy technologies', which deplete the natural resource base. Chapter 4 of the Agenda calls on nations to develop policies and strategies to spur change away from 'unsustainable consumption patterns', including energy consumption patterns.

These recommendations form an explicit response to global forest loss, which FAO figures show accelerated from about 11 million hectares a year in the early 1980s to almost one and a half fumes that rate by 1990, the worst losses occurring in developing countries in the tropics. The Agenda's references to 'energy transition' and changes in consumer behaviour specify a progressive change from unsustainable patterns of energy supply and demand to sustainable approaches incorporating environmental safeguards.

These objectives apply as much to woodfuel and charcoal use on a village scale as to the most technologically advanced industrial energy production systems. They do not imply that traditional woodfuel use is inherently less sustainable than industrial use or that other energy sources should be preferred over wood.

The Forest Principles call for 'full economic valuation' of benefits from forests, including the value of 'non-economic' goods and services and environmental benefits of all kinds, and 'fuel and industrial wood requirements'. They also recommend wider establishment of energy plantations to meet those requirements in greater measure, where circumstances restrict further utilization of established forests.

When wood energy production and use are subjected to such valuation, the benefits to consider include: stabilising effects on climate and atmosphere; conservation of soil and water resources; the reclamation of degraded land; and the maintenance of natural biodiversity in the form of genes, species and ecosystems.

These benefits persist only if they positively reinforce or enhance living standards enjoyed by people living in the vicinity of forests and use forest resources to meet important needs. Local people are otherwise deprived of rational incentives to act as stewards and managers of their own surroundings and heritage.


In Senegal annual woodfuels consumption for household energy is estimated at 3500000 tons (approximately 1450000 toe/year), which represents 67 per cent of the country's total energy consumption.

A rapid appraisal of economic benefits obtained for forests and trees gives the following results:


34000000 US$/year;

Non-wood forest products

2500000 US$/year;


160000 US$/year1.

1Woodfuel production, transportation, trade distribution and use generate about 100000 jobs per year of which 60000 are connected to charcoal making.

This simple analysis shows the crucial importance played by forests as an income source for Senegal.

For instance, the substitution of fuelwood and charcoal by imported kerosene for the 1450000 toe/year required to meet the needs of poor households would imply an investment of about US$200000000 per year.

Health aspects

The household use of simple woodfuels has been associated in the past with 'indoor air pollution' and high incidence of respiratory disease and throat or lung cancers among regular users. Consultations sponsored by the World Health Organization in 1992 suggest that in areas where fuel-saving stoves and cleaner-burning woodfuels such as charcoal have been widely promoted, the incidence appears to decline.

Health problems are on the increase, on the other hand, in some countries where fossil-based fuels have been introduced as alternatives to woodfuels. For instance, WHO figures suggest that the growing use of low-grade coal as household fuel in China has led to a marked increase in lung cancers.

Not all fossil-based fuels have this disadvantage, but the deciding factor is usually the type of cooking or heating equipment used rather than the choice of fuel. The poor standards of ventilation often found in low-cost housing also multiply health risks, and not through smoke pollution alone.

Upgrading household cooking or heating facilities, improving fuel quality and raising housing standards are general aims included in the majority of comprehensive rural development and aid schemes. These measures need not be viewed as specific to energy planning. They can also be amply justified in terms of better nutrition, food hygiene and general healthcare.

A special environmental health plea can, however, be made for favouring the use of wood and wood-based fuels in commercial or large-scale industrial applications, such as power stations or metals processing based on coal or coke. These otherwise entail burning fossil-based fuels on a scale liable to cause widespread atmospheric pollution.

Using wood as an industrial energy source is not without pollution hazards: burning woodfuels can emit significant quantities of soot and oxides of nitrogen into the wider environment, together with trace amounts of carcinogenic chemicals. But these emissions are minor compared with those of burning fossil-based fuels on an industrial scale. In Germany, the environmental effects of fossil-based energy systems have cost an estimated DM10 billion (US$6.25 billion). Almost 65 per cent of the country's trees have been damaged through atmospheric pollution in the form of 'acid rain', soot and airborne emissions of oxides of nitrogen (NOx), originating mainly in fossil-based fuel combustion by industry and motor vehicles.

'Unsustainable patterns of production and consumption, particularly in industrialized countries... [are] a matter of grave concern, aggravating poverty imbalances. [Measures must] take fully into account the current imbalances in the global pattern of consumption and production.'

Agenda 21, Chapter 4

This is the type of environmental cost now being included in the equation when assessing the environmental disadvantages and benefits of forests and forest industries versus other land uses or technologies. Such 'lateral thinking' is now being applied to the universal problem of controlling emissions of carbon dioxide and other greenhouse gases implicated in the global warming effect.

Climate and atmosphere

While alive and growing, forests and other plant biomass absorb the greenhouse gas carbon dioxide in quantities broadly equivalent to the amounts emitted when plant materials decay or are burned. They thus represent 'carbon-neutral' fuel sources or, under certain growth conditions, carbon 'sinks'. Conversely, the outright removal of forest vegetation through land clearing or degradation means that less carbon is sequestered in the foliage and woody tissues of trees. Any land use change which results in net increase in forest cover, such as establishing energy plantations, can be regarded as a potential antidote to the global warming and climate change syndrome.

Carbon taxes

Carbon taxes are surcharges levied on commercial fuels in proportion to the amount of carbon dioxide they emit in use, per standard unit of energy produced. In principle, carbon taxation should force up the price of oil, gasoline and other fossil-based fuels, so making indigenous production of renewable - including biomass - energy increasingly attractive. The cost of the tax to manufacturing industries should, in principle, be balanced by benefits to agricultural industry and lower fuel import bills, so national economic growth need not suffer overall.

The Netherlands, Sweden and Finland already impose such taxes and controversial plans are being shaped to introduce a carbon tax throughout the European Union. Some European Union states strongly oppose this move on the grounds that it might weaken the competitiveness of their industries in the world marketplace. They argue for modest carbon taxes whose revenues can be ploughed back into developing renewable energy technologies that will compete with fossil-based fuels on their own merits, without penalising industry or meddling with market forces.

In problem situations where woodfuel use is among the factors leading to permanent vegetation loss, substituting alternative fuels - even fossil-based fuels - for wood may have a net balancing effect on the global carbon dioxide 'budget'. Substitution need not, however, be considered a permanent solution. If land and vegetation can be restored to sustainable use, substitute energy sources may no longer be needed.

Forests are preferable in terms of their beneficial effects on soil conservation, land reclamation and the safeguarding of watersheds and biodiversity. In relation to climate and atmosphere, therefore, once demand for biofuels is established, it makes sense for biomass energy production to evolve towards wood energy use.

Transition towards wood energy and other renewable energy sources can be speeded up by introducing tax, tariff and subsidy mechanisms. Many governments faced with meeting the reduced greenhouse gas emission targets agreed at UNCED, including most of the Scandinavian nations, have begun to experiment with financial measures such as carbon taxes that discourage fossil-based energy applications and reward RSE use.

An alternative to carbon taxes, proposed in the USA and elsewhere, is the notion of 'traceable permits' to emit carbon dioxide and other greenhouse gases. These proposals foresee that industries or concerns which emit larger-than-average quantities of greenhouse gases, such as power utilities, would pay credits to other industries or concerns whose impact on global warming was neutral or beneficial (such as bioenergy producers), in return for a permit allowing them to continue to emit at the existing rate.

An international variation on the idea of 'traceable emission rights' has also been promoted. Such a scheme might allow, for example, a highly industrialised country to meet its national greenhouse gas emission targets and obligations by investing heavily in reforestation or forest conservation projects in developing countries with significant tropical forest assets. The global environmental gain would - in principle - cancel out the permit-holder's continuing over-production of emissions.

However, there are many who disapprove of traceable emission permits as 'licences to pollute'. Such systems would, moreover, prove complicated to administer, monitor and enforce. Straightforward regulation of energy production and use is another option which offers the advantage of simplicity.

FIGURE 14 Global warming and the carbon cycle

Major reservoirs (in Gtc) in bold Fluxes (in Gtc/yr) shown by arrows.

Source: UNIDO, 1990

Although not motivated by global warming fears but by concern over the fate of natural forests, strict regulations were introduced in Brazil in 1965. These require that by 1995 all charcoal produced for industrial use should come only from sustainable sources such as managed wood energy plantations. These regulations, combined with tax incentives to establish commercial tree farms, have led to the establishment of some five million hectares of plantations, which currently supply 35 per cent of the country's total charcoal production.

Wood energy and land reclamation

Past mismanagement of land has overstrained local ecosystems and led in many places to the spread of desert or semi-decertified conditions. Over-irrigation and soil erosion have degraded millions of hectares of once fertile land in South Asia, Africa and the dry tropics as a whole. Many areas have simply been abandoned. Others are farmed intermittently, yielding minimal returns. Reforesting these wastelands on a grand scale would, some conservationists argue, have the effect of reversing global warming entirely by sequestering carbon (removing it from atmospheric circulation for a time) in the form of massive increments of forest vegetation.

Other conservationists question whether such a programme would decisively counteract the global warming hazard, though it could make a tangible difference. The proposal has not, in any case, carried sufficient force to persuade development planners and investors to undertake the massive replanting programmes necessary to achieve so comprehensive a scheme, even if tree varieties could be developed that would tolerate the adverse growing conditions of degraded land.

It has been suggested that if land rehabilitation schemes could be coupled with bioenergy production programmes, such initiatives might prove significantly easier to justify. The effort would be rewarded by worthwhile economic and social dividends in the medium term, as well as many other long-term environmental benefits in addition to carbon sequestration. Chapter 12 of Agenda 21 recommends that preventive measures against desertification and drought should be adopted with a view to increasing the vegetation cover of land in danger of degradation. Soil conservation, afforestation and reforestation are mentioned as the chief means towards this end. Community-based agroforestry, incentives for forestry investment and activities that reduce pressure on fuelwood resources are specified as desirable measures.


On the shores of Lake Baringo, Kenya, a novel approach to using woodfuel and fodder production as a means to restore land severely denuded through overgrazing has been under test for more than 10 years. Solar powered electric fences exclude grazing animals from formerly fertile areas that have become eroded and face the threat of desertification.

As the protected vegetation regenerates, it supplies local farmers with a generous quota of firewood, hay for dry season fodder and long grasses for thatching. The scheme has won the support of local people, who donate land to the scheme and repossess it once the vegetation cover is restored.

Even on a relatively modest scale, afforestation, reforestation and soil conservation schemes connected to wood energy development can deliver palpable benefits, in view of the valuable environmental functions forests serve by safeguarding watersheds, soil nutrients and biodiversity. In this context of primary environmental care, establishing and maintaining woodlots, shelterbelts, agroforestry plots and any other form of tree cover is often the most advantageous step any community can take towards a greater degree of environmental security and economic self-sufficiency.

Biodiversity dividends

Relating wood energy development to the conservation of biodiversity (naturally occurring genes, species and ecosystems) is not a simple equation. Replacing species-rich natural forests or wetlands with energy plantations dominated by a single tree species or a limited mix of species will obviously be a retrograde step under most circumstances. If, however, energy plantations replace crop monocultures or are introduced as a reclamation measure on abandoned lands where biodiversity stands virtually at zero, the result will be an equally self-evident boost to the variety of plant and animal life through the proliferation of mixed habitat, especially as plantation systems mature and evolve.

Between these extremes, assessing the value and potential of wood energy production in the light of biodiversity is more complex. The Convention on Biological Diversity mooted at UNCED offers little help in this respect, concentrating as it does on ecosystems that show little evidence of human modification and are hence most likely to contain a large variety of plant and animal species.

Nevertheless, forestry practices [including woodfuel extraction] need not be incompatible with the conservation of biodiversity in natural ecosystems. Even man-made or man-modified forest ecosystems can encourage biodiversity to a noteworthy degree. Wildlife legislation and other legal or regulatory devices restrict access to many natural forest areas, mainly in the interest of preserving biodiversity. Yet the majority of natural forests, and the plants and animals they harbour, exist outside protected area boundaries.


The High Weald is an upland area of south-east England, an extensive mosaic of farms and woodlands unchanged in overall pattern since the thirteenth century. The 'ancient woodlands' of the area originated as natural forests but were modified and expanded in the past to supply charcoal for bygone use in iron smelting. Traditional management persists, based on coppices harvested in eight-year rotations and composed of a mix of indigenous oak or ash and introduced chestnut or hornbeam.

Local woodcutters are licensed by farmers or landowners to harvest poles and firewood in return for maintaining the coppice system. Larger poles cropped from the coppices have been put to a variety of modern craft uses, including the production of fence palings used in the building trade to screen off construction sites. Thinnings and harvest residues were till recently sent to paper mills for pulping. Lately, however, the recycling of waste paper has sharply reduced demand for harvest residues, while recession in the construction trades has diminished the fencing market. Only rising local demand for firewood for domestic heating enables some craftworkers to secure a living and continue to maintain coppice systems in economic shape.

Many High Weald woodlands that lack such maintenance have reverted to a wild condition. Paradoxically, they harbour less biodiversity in this state than as coppices. Coppicing intermittently opens up the woodland canopy to extra light and moisture, creating microclimates at random that would normally only be found at the woodland's edge or in clearings. A rich wildlife fauna, including several unique butterfly species, takes advantage of this effect, while trees with a spreading habit that might shade out other species are kept in check.

Social stability is also affected. As the economic uses of coppice woodlands decline, young people no longer feel motivated to learn the skills of traditional woodcraft and move away from the area to seek a living in urban centres. Within a generation, 'vernacular' skills built up over more than 400 years may become unavailable, even though the demand for them may recover in due course.

Such experiences illustrate the mutually supportive connections that exist around the world between wood energy, biodiversity and rural development, regardless of the degree of industrialization that forms their background.

To secure the regenerative capacity and biodiversity of these forests, self-evident value must be added to their maintenance and use and a balance struck between social and biological need.

Many experienced forest societies achieve this balance by a variety of means, including traditional woodfuel use. Others have learned to adopt innovative multiple-use practices to equally valuable effect. In either case, local knowledge and participation is as important as the technical expertise of outsiders when it comes to reconciling biological, social and economic imperatives.


Near the south coast port of Tumaco, in Colombia, local urban demand is supplied by charcoal produced on a small scale from natural mangrove (Rhizophora species) forests growing along creeks and inlets near the main road leading to the port.

Charcoal production absorbs the labours of a cooperative group of families, numbering about 30 adults and 20 children, whose entire income is earned from charcoal trading. A 1981 FAO report showed that their livelihood was in serious jeopardy from falling revenues following over-supply of cheap imported kerosene on the local market.

Striking a balance between such rival energy sources is no simple matter. If charcoal were to hold a monopoly over trade in cheap cooking fuels, wood extraction for this purpose might soon grow to become a serious threat to the mangrove ecosystems, where fish breed and feed, so jeopardising the fisheries on which many townspeople depend for a living.

Contents - Previous - Next