“Forests put an effective break on the warming climate, as
trees have an appetite for carbon dioxide, the main greenhouse gas.
The hungriest of all is a young, growing forest...The type of forest
needed to control the greenhouse effect is different from that needed
to nurture biodiversity; in fact, the faster the seedling grows the
better....In terms of controlling the greenhouse effect, forests should
be regenerated, and more use made of timber as a raw material”1.
This is the view of the Finnish forest industry and, perhaps, a fair representation of the forest industry as a whole. These two sentences, with their implication that, in order to “control” the greenhouse effect, we need to log old forests, replace them with young plantations and increase our timber consumption, are a good example of the way in which the threat of climate change has been used by the forest industry to justify its intensive forest management practices.
The forests and climate change issue is extremely complex. A mass of information has been produced and a range of theories have been put forward concerning the potential of the world's forests to absorb large quantities of atmospheric carbon dioxide and thus offset that produced principally by the burning of fossil fuels. This briefing is designed to give an overview of the issues and expose some of the myths that have been generated.
The greenhouse effect is a natural occurence and its warming effect is one of the processes which permits life on earth. However, emissions of greenhouse gases (GHGs) caused by human activity (anthropogenic emissions) have increased concentrations of these gases in the atmosphere - causing more heat to be reflected back to earth - resulting in global warming. It is thought that the enhanced greenhouse effect and the resulting global warming will lead to a change in the world's climate. For further explanation of climate change, greenhouse effect and global warming, see the glossary. The main “greenhouse gases” and their overall contributions towards the greenhouse effect are listed below.
Table 1: Greenhouse Gases and Their Contribution Towards the Greenhouse
Effect
|
Greenhouse Gases |
Overall Contribution % |
|
Carbon Dioxide (CO2) |
64 |
|
Methane (CH4) |
19 |
|
Chlorofluorocarbons (CFCs) |
10 |
|
Nitrous Oxide (N2O) |
5.7 |
|
Others |
1.3 |
|
Total |
100 |
Source2
There is now little doubt in the scientific community that climate change is a very real threat to the global environment. At the Rio Earth Summit in 1992, most of the world's governments acknowledged the problem by signing the Framework Convention on Climate Change (FCCC), which aims to stabilize atmospheric greenhouse gas (GHG) concentrations. A key aim is for industrialised countries to return emissions of CO2 to 1990 levels by the year 2000.
However, there has been a great deal of debate about how countries should actually go about reducing or offsetting emissions of GHGs, especially the main greenhouse gas CO2. (It is clear that the vast majority of countries will not return emissions to 1990 levels by the year 2000). One suggested option is to offset CO2 emissions by planting trees. In 1997, the year of the UN Convention on Climate Change, this idea seems to be gaining more currency with countries such as Japan, and even some industry organisations3,4. However, serious questions remain concerning the feasibility, effectiveness and overall environmental benefits of such a strategy.
The global carbon cycle involves the natural emission, absorption and storage of huge quantities of carbon. It has been estimated that, every year, nearly two hundred billion tonnes of carbon are exchanged between the earth/oceans and the atmosphere5. The change in carbon concentrations due to emission and absorption is known as the carbon flux. Net emitters of carbon are known as carbon sources and net absorbers of carbon are known as carbon sinks. Carbon can be stored in a number of ways such as in coal or oil, in the oceans or in organic matter in plants. (For more explanation of carbon sinks, sources and stores, see the glossary).
The greatest stores of carbon are believed to be the world's oceans and fossil fuel reserves. On land, carbon is stored in ground litter, soils and plants. Forests are thought to contain about 80% of all above-ground and 40% of all below-ground terrestrial organic carbon6.
Trees absorb carbon dioxide from the atmosphere. This is converted into carbon, which is stored as biomass (see glossary) in the tree, and oxygen, which is released back into the atmosphere. Young trees grow more rapidly and absorb more carbon dioxide than old trees which, although they absorb less carbon dioxide, have much greater stores of carbon in their biomass. In Scandinavia, for example, trees can live for up to 700 years, storing carbon for long periods. However, they eventually die and rot releasing the stored carbon back into the atmosphere7.
Carbon dioxide that is absorbed by trees which are subsequently turned into timber and paper is also eventually returned to the atmosphere. This happens either when these products are incinerated, or when they rot in landfill and release methane - another, more potent, greenhouse gas. Timber products generally have a longer life than paper products so can therefore store carbon for longer, sometimes for centuries. However, most wood products are not so long-lived8,9. Re-use and recycling prolongs the life of both timber and paper and can therefore delay the release of stored carbon back into the atmosphere.
The natural forests of the world can be split broadly into two main categories. The tropical forests that lie either side of the equator and the temperate and boreal forests that lie largely in the northern hemisphere (with a small proportion in Australia, New Zealand, Argentina and Chile).
Before 1900, the greatest CO2 emissions were caused by deforestation due to agricultural expansion in temperate countries. Since then the balance of emissions has changed as fossil fuel consumption soared, temperate deforestation decreased and tropical deforestation increased. Since the 1940s, tropical deforestation has accounted for by far the greatest net emissions from the natural environment, although these are still far below emissions due to fossil fuel use10. In 1990 fossil fuels accounted for the release of some 6 billion tons of carbon into the atmosphere whereas deforestation accounted for approximately 1.7 billion tons11. These emissions are offset to some extent by absorption of carbon into oceans and forests.
Table 2: An approximation of current net annual global carbon flux in Gt (billions of tons*) of carbon.
|
Activity |
Source+/Sink- (Gt) |
|
Absorption by Oceans |
-2 |
|
Absorption by Forests |
-2 |
|
Deforestation |
+1.7 |
|
Fossil Fuel Use |
+6 |
|
Total |
+3.7 |
In order to alleviate climate change there must either be an increase in the amount of carbon that is taken from the atmosphere and stored for long periods or there must be a reduction in anthropogenic carbon emissions (or a combination of both).
It has been suggested that forests and forestry have the potential to achieve these through:
Globally, annual deforestation amounts to about 13.7 million hectares (an area the size of England)14. This deforestation is occurring in the developing countries of the south, although it is also thought that some forest loss may be occurring in northern countries like Russia15,16. As has already been mentioned, this deforestation is releasing huge quantities of carbon into the atmosphere.
It has been widely recognised that curbing this forest loss is essential for both the maintenance of biodiversity and for cutting greenhouse gas emissions17.
A more contentious issue is the role of old forests and young forests in the greenhouse effect. The forest industry has often used the climate change issue as a way of suggesting that old-growth forests should be logged and replaced by managed forests. For example, the Finnish Forestry Association have said that; “There is a danger that the country's forests will grow too old and this may translate into environmental problems. When forests age, they... begin to emit more carbon dioxide than they can absorb”18.
The implication that old forests are at best useless and at worst actually contributing to climate change is nonsense. Whilst it is true that young trees absorb more carbon dioxide as they are growing, this is stored as biomass in old trees. The old forests of the boreal belt are massive storehouses of carbon. Logging and using these forests will cause the release of the stored carbon and, even if they are replaced with man-made forests intended for timber production, there will be a significant reduction in the amount of stored carbon on this land19. According to the Intergovernmental Panel on Climate Change (IPCC), “New protected areas should include those that contain large C [carbon] pools, such as forests growing on peat soils at high and low latitudes, and high biomass old- growth forests”20. This is further supported by Finnish forestry researchers who state that, “There is a need in western Europe to reserve new forest areas for nature protection. Such areas would support higher biomass levels than areas managed for maximum sustained yield”21. Perhaps of even greater importance are the massive areas of high biomass old-growth forest in Canada and the Former Soviet Union and, of course, the tropical rainforests.
In Theory
Various estimates have been made of the land area that is potentially
available for forestation **.
It has been suggested that there may be anything between 385 and 580
million hectares available in the tropics and anything between 100 and
200 million hectares in temperate latitudes22,23,24.
Estimates can also been made of the amount of forest needed to offset the excess carbon in the atmosphere. For example, to offset the approximate 3.7 billion tonnes of excess carbon in the atmosphere annually could require 528 million hectares of fast growing tropical plantation (an area more than ten times the size of Spain) or 1682 million hectares of Canadian boreal forest plantation (an area nearly twice the size of Brazil)25.
In theory at least, forestation would seem to have the potential to absorb significant quantities of carbon thus helping to offset the greenhouse effect. In practice, however, the situation is quite different.
In Reality
The IPCC estimates that anthropogenic carbon emissions will increase
by 1-2.39% per annum from 1990 until 202026.
This means that, in 1997, the annual increase in global carbon emissions
is between about 65 and 170 million tonnes27.
The current increase in forest area in the temperate and boreal regions is approximately 1.8 million hectares per annum28. At best this will be absorbing about 10 million tonnes carbon per annum net29, just 7-16% of the annual increase in carbon emissions. This means that forestation is currently making little dent in the projected increases in carbon emissions let alone reducing the overall levels of atmospheric carbon.
Despite these statistics, some statements by the forest industry give the impression that its man-made forests are actually making a significant difference. The Swedish Pulp and Paper Association says, “Nordic forests slow down the greenhouse effect. The forests of Sweden and Finland capture enormous amounts of carbon dioxide, thus counteracting the greenhouse effect and the concomitant climatic changes...”30 The reality of the situation is that, in global terms, the forests of Sweden and Finland absorb a tiny fraction of the carbon released due to fossil fuel use. The wood product industry's forests in Sweden and Finland absorb about 3.5 million tonnes of carbon annually31. This is enough carbon to offset just 0.06% of annual global fossil fuel emissions, or just 2-5% of the annual increase in carbon emissions.
In the case of the UK, even if 1 million hectares of new forest were established (a 40% increase in forest area) this would only absorb about an extra 1% of current annual UK carbon emissions32,33. At current rates of forest establishment, it will take nearly 100 years to plant 1 million hectares34.
A Temporary Measure
Even if massive forestation took place world-wide, this would only postpone
the need to drastically reduce carbon emissions. This is because the
forest would only capture and store carbon during its years of growth.
Once it reached equilibrium, although the forest would provide a long-term
carbon store, overall it would cease to act as a carbon sink35.
If this forest was subsequently harvested and made into wood products
this would speed up the release of much of the carbon and just postpone
the eventual release of a small proportion of it (see next section).
This means that forest establishment could only ever be a temporary measure which would provide a “window of opportunity” of perhaps 30-100 years in which carbon emissions could be cut36.
Feasibility
Although climate change is a very serious threat to the global environment,
forestation and forest management need to take into account more than
just carbon absorption and storage. Social and cultural factors also
need to be considered as does the maintenance of biodiversity. There
is little point in the blanket afforestation of an area which results
in the degradation/destruction of the very ecosystem that is supposed
to be being conserved.
It may well be more socially and environmentally acceptable to encourage forests to naturally regenerate (rather than establish more intensive man-managed forests). In fact some analyses have shown that, “...natural regeneration is potentially easier and cheaper, and more acceptable to the local population than plantation based forestation”37.
It is also important to consider the feasibility of forest establishment on a massive scale. A number of problems are inherent to intensive forestation programmes, especially those involving non-native species (which are used to increase biomass yields). Concerns have been raised about the environmental impacts, and thus long term sustainability, of plantation forestry in both temperate and tropical climates. The problems can include: soil erosion, soil nutrient degradation, a reduction in biodiversity, vulnerability to pest attack and the adverse effects of fertilizers, pesticides, herbicides and fungicides on soils and water38,39,40,41. This means that, ultimately, intensive forestation for carbon storage could prove to be self defeating. The use of fertilizers is worth particular mention in this context because, according to unofficial industry figures, between 2-3% of the world's fossil fuel consumption is used for fertilizer production42.
In any case, the forestation of areas of land large enough to significantly offset carbon emissions is unlikely to happen due to competing land uses (especially agriculture), and the long term investment required. The Food and Agriculture Organisation conclude that, “Economic and population pressures in many regions make net afforestation difficult to achieve”43.
Tree planting could, however, become more financially attractive if it is seen as an alternative to investing in, perhaps more costly, emissions reduction. A number of countries, including the USA and Japan, and some industry organisations, are starting to look at what are known as 'activities implemented jointly' (AIP) or joint implementation plans44,45. In terms of forestry these involve a developed country (donor) investing in forestation/forestry programmes in a developing country (recipient). This is usually a cheaper option for the donor than investing in either forestry or other greenhouse abatement strategies at home46. Although this may benefit the recipient in terms of improving forest management or increasing forest area, there is a danger that these programmes will be seen by the donor as an alternative to taking action to reduce emissions at home. There is an added danger that industry will get involved to use them as a “licence to pollute”. It should also be remembered that, as has already been mentioned, forestation is a temporary measure and not a solution. It is therefore vital that forestation programmes, as well as being carried out sustainably, are not used as an alternative to emissions reduction.
The forest industry promotes the idea that old forests should be replaced
with young managed forests which can then constantly add to carbon storage
through conversion into timber and paper products. However, this proposition
is misleading. Even after a number of rotations, the carbon stored in
the managed forest (and the remaining forest products produced from
it) is less than that stored in an unmanaged old-growth forest47.
The forest products industry also maintains that the production of paper
and timber is “in balance with nature” because the
carbon dioxide that it produces through its operations is equal to,
or less than, that absorbed by growing trees48.
For example, the Scandinavian forest industry maintains that, “Growing
forests consume carbon dioxide and offset the greenhouse effect...The
forest and its products are part of a sustainable ecocycle”49.
The diagram below is a typical example of how the forest industry represents
the carbon “ecocycle”50.
This depiction of the carbon cycle does not include any GHG emissions from forest establishment, management and harvesting, the transport of timber, production of wood products and the transport of these products to the consumer. By leaving these emissions out, the forest industry gives a grossly inaccurate view of its impact on the environment.
An alternative representation of the forest industry carbon cycle is given below.
This diagram shows that the forest industry emits GHGs at almost every stage of the forest product life cycle. In fact, the most rigorous life cycle analysis of the GHG emissions of the paper industry to date concludes that, “The pulp and paper industry is a significant emitter of greenhouse gases. While plantations maintained to supply fibre for pulp production store large amounts of carbon on land that was previously not forested, this carbon storage is insufficient to offset the even greater emissions from fossil fuel use in manufacture and from paper disposed in landfills”51. This means that the paper industry is actually adding to the problem.
This is certainly not the impression given by Swedish forest products company MoDo who, in 1990, said that,“...it should be noted that the forests farmed for the paper industry actually convert 10 times more CO2 into tree growth than the uncultivated temperate forest, whilst simultaneously producing 10 times more life giving oxygen. The forestry industry therefore stands virtually alone in actively combatting the single most disturbing environmental issue of the day, that of global warming...”52. It is hoped that, in 1997, the attitude of the paper industry has changed.
The manufacture of timber products is different to paper in that it uses less energy (although the manufacture of some panel products takes a similar amount). Also, the carbon is stored for much longer periods postponing the eventual release back into the atmosphere. However, the total carbon emissions from establishment, management, manufacture, transport and eventual landfilling/ incineration are still likely to outweigh absorption in timber industry forests.
If the storage of carbon in forest products is to become more efficient, there must be an increase in the longevity of wood products. This would increase carbon storage time and thus create a greater “window of opportunity” in which carbon emissions could be cut.
As well as the manufacture of long-lived timber products for building, measures such as the re-use and recycling of timber and paper could be used to lengthen the time that carbon is stored. These could also reduce the demand for “virgin” forest products and thus take some of the pressure off the world's natural forests which are massive carbon stores.
Despite these benefits, the forest industry has actually used the greenhouse effect to argue against increasing the use of recycled paper. For example, the Finnish Forestry Association has said that, “The status of European forests will actually deteriorate if recycling is increased at the expense of primary fibre in paper production. Forests in this scenario will grow old. Decomposition of dead wood will release carbon dioxide into the atmosphere increasing pollution”53.
Again the forest industry talks about carbon absorption/ release rather than carbon storage and thus misses the point. The Intergovernmental Panel on Climate Change (IPCC) concludes that “Paper recycling is another strategy with the potential to reduce harvest levels and promote greater carbon conservation”54.
Another suggested method of using forest products to offset carbon emissions is that of substituting building
materials such as aluminium, steel, plastics and concrete with timber. The theory is that these other materials require more energy for their manufacture than timber and are thus responsible for greater carbon emissions. Therefore, if they were substituted with timber, there would be a reduction in carbon emissions, along with the added benefit of an increased amount of carbon in long term storage.
The advantage of this theory over just planting more forest is that
it would actually reduce anthropogenic carbon emissions rather than
just temporarily offsetting them.
Unfortunately, no research could be found comparing the full energy
budget of timber, wood panel products, steel, concrete, aluminium and
plastic. At the time of writing, only a comparison of studies looking
at just the manufacturing process could be found55.
Although this shows that sawn timber manufacture requires less energy
than any of the others, it also shows that the manufacture of panel
products requires more energy than the manufacture of concrete and it
is worth noting that the manufacture of recycled steel (which requires
less energy than some panels56)
was not analysed at all.
To make a truly informed decision on the environmental impacts of any of these materials would require a full life-cycle analysis looking at the impacts of extraction/ harvest, transport, production, use and disposal. As yet, this has not been done so it is difficult to make an accurate judgment on the effectiveness and desirability of a “replacement strategy”. If it can be shown that sawn timber or panels use less energy overall then, in terms of climate change, it may make sense to use them. However, unless the sawn timber and panels were being produced in an ecologically sustainable fashion, the impact of an increase in timber consumption would most likely mitigate against this strategy due to the increasing pressure put on the world's natural forests.
In terms of the potential effectiveness of a “replacement strategy”, this will differ for different countries or regions, but an impression can be gained from a study by a Working Group on Forest Use in Australia who, “...estimated that the effect of using all timber framing as oppose to all metal framing in new housing would reduce Australia's annual greenhouse emissions by less than 1 per cent”57. Although this sounds insignificant, it could be useful if it augments a much wider strategy to cut energy consumption.
There are other forest measures which, although they are not necessarily associated with large scale forestry or the forest industry, should be considered when discussing climate change. These are agroforestry (see glossary) and the production of energy from biomass.
Agroforestry
Agroforestry has the potential to either act as a temporary carbon sink
and long term carbon store (e.g. trees planted and left standing) or
actually reduce current carbon emissions (trees grown for biomass energy).
It has also been suggested that agroforestry in tropical countries can
improve soil fertility to an extent that will reduce the need for further
expansion into forested areas, thus curbing deforestation58,59.
In fact, it is even thought that agroforestry systems could provide
one of the most effective means to slow deforestation by resource poor
farmers in tropical latitudes60.
Agroforestry is often small scale but if it is encouraged and repeated by a large number of land-users this increases the potential to either store carbon or reduce anthropogenic carbon emissions. One study estimates that, in the tropics, 63 million hectares could be converted to agroforestry systems in the next 50-60 years61. At most, this would absorb 1.6 Gt carbon over this whole period (an average of about 2.7 million tons per annum) which is less than 1% of projected carbon emissions. The IPCC sees agroforestry as having a greater potential than this. It estimates that, by the year 2045, 0.25 Gt carbon could be being absorbed per annum, although it recognises that there is a great deal of uncertainty about factors such as land availability62.
It is important to remember that these estimates refer to the sink potential of agroforestry. As has already been mentioned, the sink would only be temporary and the storage time of the carbon would depend on the end use, if any, of the trees. This means that, in terms of making any long term difference to curbing the greenhouse effect, the most effective use of agroforestry would be to actually cut carbon emissions through either reducing deforestation or producing biomass energy (or both).
Biomass Energy
Currently about 15% of the world's energy requirements are satisfied
by burning biomass63.
Biomass energy is normally derived from wood although in some countries
a large proportion of biomass energy comes from burning dung or agricultural
residues. Biomass is the main fuel of the developing world where it
accounts for about 35% of total energy use64.
In terms of greenhouse emissions, biomass energy from plants operates on the basis that the CO2, that is absorbed by the plants when growing, is released when they are burned thus resulting in no net addition to atmospheric CO2. However, it is likely that fossil fuel energy would be used to plant, manage, harvest and transport the biomass crop, thus releasing CO2 and reducing the benefits. That said, energy from biomass does have advantages as it replaces energy that would otherwise be generated using fossil fuels thus reducing carbon emissions rather than, as with tree planting, just temporarily offesetting them. Therefore increasing the use of biomass energy in order to decrease consumption of fossil fuels has the potential to significantly reduce carbon emissions.
Estimates of the amount of land that would be required for biomass production in order to stabilize global atmospheric carbon concentrations range from around 550 million hectares to nearly 800 million hectares (an area larger than Australia)65. However, as with forestation, there are significant regional variations in land requirements and land availability. For example, in the UK, it has been estimated that about one and a half times the land area would need to be planted with biomass to totally offset national emissions of carbon66. Also, as with any large scale land-use project the establishment of biomass plantations could have environmental consequences such as land degradation and threats to biodiversity67.
However, it is possible to produce biomass energy in a sustainable way. For example, in the UK, guidelines have been formulated for the establishment of short rotation coppice plantations for energy production (see glossary)68. The emphasis is on fairly small scale schemes designed to serve mainly local biomass power generating plants although larger scale schemes are being developed to serve the national grid. While even the largest generate just 3% of the energy of a coal fired power station, biomass is one of many forms of renewable energy that together can make a significant contribution to GHG reduction.
In summary, there is little doubt that the development of agroforestry systems (to reduce deforestation or produce energy) and/or energy from biomass plantations could help to reduce some of the world's anthropogenic carbon emissions. These will only be effective if they form part of a much wider package of measures designed to reduce carbon emissions.
As well as considering how forests can affect climate change, it is also important to try and understand how climate change will affect the world's forests.
There is currently a great deal of uncertainty concerning what effect climate change will have on trees. It has been both suggested that a rise in temperature and atmospheric CO2 could stimulate tree growth rates and thus increase carbon absorption, and also that a rise in temperature could stimulate respiration and thus increase carbon release69,70. There is currently no firm evidence either way.
There is also uncertainty about how forest areas and types will respond to changes in temperature. For example, one group of scientists maintains that, “No concrete evidence is available for predicting how tropical forest ecosystems are likely to respond to CO2 enrichment and/or climate change”71. However, the balance of opinion seems to be that the greatest changes will occur in the boreal latitudes and the least in the tropics, with temperate forests experiencing only moderate changes72. This is because firstly, it is thought that the change in temperature is likely to be greater towards the poles than in the tropics and secondly, that the boreal forests of the north are not as diverse and not as resilient as the tropical forests.
With an increase in temperature it is thought that the southernmost parts of the boreal forest will revert to grassland while the forest moves north into the tundra regions. The northern migration of the forest is expected to be very slow, especially in relation to the forest loss expected in the south due to increased fire frequency, pest outbreaks, drought and competition from temperate tree species. Although in the long term forest areas could “migrate” and re-establish, in the short term large amounts of carbon could be released into the atmosphere during the transition due to irregular and large scale losses of trees73,74.
The potential loss of large areas of boreal forest releasing huge
stores of carbon could also have a “positive feedback” effect
speeding up climate change and increasing the rate of forest loss. The
rate at which this could occur, and the effects that it will ultimately
have, are difficult to quantify.
In the face of so much uncertainty and the possibility of such drastic changes, a precautionary approach is required. This means that action to curb global warming - a reduction in GHG emissions and deforestation - is needed immediately.
The world's forests play an extremely important role in the global carbon cycle. Their vegetation and soils are the major terrestrial sink for atmospheric carbon and the way in which they are used and/or abused has a significant impact on the greenhouse effect (mainly through deforestation).
This briefing has shown that there is some potential for a variety of forest related measures to help curb climate change, the most effective of which involve reducing current carbon emissions (such as replacing fossil fuels with biomass energy) rather than trying to temporarily soak them up (afforestation or timber/paper production). It is likely that the most environmentally benign measures will usually be those that involve small scale changes to current practices (such as agroforestry and local biomass energy production) rather than large scale land use changes such as major afforestation programmes.
It is also clear that forestry will only ever play a “supporting role” and, unless carbon emissions are reduced through energy efficiency and the use of alternative energy sources, the threat of climate change will remain. This briefing has shown that the timber industry's claims concerning the ability of forests to “combat” or “counteract” global warming, the implied “environmental threat” posed by old forests, the implied “environmental threat” posed by increasing recycling and the “sustainability” of producing paper and timber are at best, questionable and at worst, nonsense.
The most important points to draw out from this briefing are as follows:
Despite the importance of climate change and the threat that it poses, sustainable development requires that a whole range of factors are considered in forestry, not least of which is biodiversity. It would be pointless to pursue a strategy for dealing with climate change that has its own adverse environmental impacts. For example, it could be self-defeating to follow a greenhouse gas abatement strategy which involves increasing timber consumption because this could encourage the destruction of the very natural forests (in Canada, Alaska, Russia and Scandinavia) that are threatened by climate change.
Finally, it should be remembered that this briefing has dealt solely with forestry and climate change and, as such, has not considered any of the other potential benefits of forests and forestry such as biodiversity conservation, soil stability, amenity/recreation, cultural value and their role in hydrological cycles. Also this briefing has dealt almost exclusively with the carbon cycle and approximately 36% of GHG emissions are not CO275. This means that strategies for reducing emissions of the other GHGs are extremely important and that any strategy based on CO2 alone will be unlikely to succeed in curbing climate change.
Afforestation: Where trees are planted on previously unforested
land.
Agroforestry:This involves incorporating tree/ woodland growing
into agricultural systems. For example, trees can be planted around
houses, in or around fields or in small woodlots. Also, trees can be
planted to conserve soil, act as windbreaks or boundaries and provide,
amongst other things, shade, fuelwood, timber and fencing material76.
Anthropogenic emissions: Emissions caused by human activity.
Biomass: A term used to describe a quantity or weight of organic
matter. Biomass energy is energy produced by burning organic matter
or by-products of organic matter.
Carbon Flux: A term used to describe the flow of carbon (absorption
and release).
Carbon Source: Something which is a net emitter of carbon.
Carbon Sink: Something which is a net absorber of carbon.
Carbon Store: Something which has a store of carbon.
Climate Change: A term referring to the changes that will occur
to the global climate as a result of an increase in average temperature.
Forestation: A term that refers to both afforestation and reforestation.
Forest Products: Anything made from wood (ie timber and paper).
Global Warming: The predicted rise in the average temperature
of the earth as a consequence of the increase in heat radiated back
to earth by increased concentrations of “greenhouse gases”
in the atmosphere.
Greenhouse Effect: The process whereby the sun's warmth is trapped
in the lower atmosphere of the earth by a number of gases (including
carbon dioxide). These gases let solar radiation through but reflect
back the warmth radiated from the earth.
Reforestation: Where trees are planted on an area that was recently
forested.
Short rotation coppicing: A silvicultural system whereby an
area of young trees are cropped on a regular cycle (every three years
or so)
Out of the Woods: Reducing Wood Consumption to Save the World's Forests - A Plan for Action in the UK. (report) April 1995.
Out of the Woods; Reducing Wood Consumption to Save the World's Forests. (briefing) April 1995.
The Environmental Impacts of Paper Manufacture. October 1996.
Sustainability and Logging in Canada's Forests. 1995.
The Good Wood Guide (third edition), 1997.
Scandinavian Forests and Forest Product Companies, 1997.
Climate Change Fact Pack, 1997.
To order any of these publications please contact; Publications Despatch, Friends of the Earth, 56-58 Alma Street, Luton LU1 2PH Tel: 01582 482297.
Peter Hardstaff
August 1997
Published by Friends of the Earth Ltd
© Friends of the Earth Ltd
Friends of the Earth England, Wales and Northern Ireland
26-28 Underwood Street
London N1 7JQ
Telephone (0171) 490 1555, Email: info@foe.co.uk
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1. Finnish Forest Industries Federation, (1995),
The Way of Wood; Forest Industry and the Environment, Finnish
Forest Industries Federation, Helsinki, Finland.
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2. Calculation based on figures published
in Watson.R.T et al (eds), (1996), Climate Change 1995; Impacts,
Adaptations and Mitigation of Climate Change: Scientific and Technical
Analyses, published for the Intergovernmental Panel on Climate Change
by Cambridge University Press, Cambridge, UK.
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3. Hadfield.P, (1997), Japan Fiddles While
the World Warms, New Scientist, 31 May 1997.
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4. Nuttall.N, (1997), Drivers Urged to
Plant Trees to Beat Pollution, The Times, 12/6/97.
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5. Collins.C, (1995), Forests and the Carbon
Cycle; emerging opportunities for native forest protection and afforestation
in New Zealand, Department of Conservation, Wellington, New Zealand.
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6. Watson.R.T et al (eds), (1996), Climate
Change 1995; Impacts, Adaptations and Mitigation of Climate Change:
Scientific and Technical Analyses, published for the Intergovernmental
Panel on Climate Change by Cambridge University Press, Cambridge, UK.
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7. Kiebitsch et al, (1992), Temperate amd
Boreal Forests, Section 5 of the Draft Contribution to the 1992
Intergovernmental Panel on Climate Change Supplement - Task 4: Forestry
Related Issues, IPCC Secretariat, Geneva, Switzerland.
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8. Harmon et al, (1990), Effects on carbon
storage of conversion of old-growth forests to young forests, Science,
247:pp699-702.
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9. Thompson.D.A & Matthews.R.W, (1989),
The Storage of Carbon in Trees and Timber, Research Information
Note 160, Forestry Commission Research Division, UK.
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10. Brown.S et al, (1993), Tropical Forests:
Their Past, Present and Potential Future Role in the Terrestrial Carbon
Budget, Water Air and Soil Pollution Vol.70 Nos 1/4, October 1993,
pp71-94, Kluwer Academic Publishers.
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11. Trexler.M & Haugen.C, (1995), Keeping
it Green: Tropical Forestry Opportunities for Mitigating Climate Change,
World Resources Institute, Washington D.C, USA.
return to text
* 1 ton = 1.016 tonnes
return to text
12. Trexler.M & Haugen.C, (1995), Op
Cit.
return to text
13. Collins.C, (1995), Op Cit.
return to text
14. Food and Agriculture Organisation (FAO),
(1997), State of the World's Forests, 1997, FAO, Rome.
return to text
15. Pearce.F, (28/3/1993), How the West
is Attacking Russia, The Independent on Sunday.
return to text
16. Alexeev. Dr.V, (1992), The Boreal Forests
of Russia, in Abstracts and Proceedings of the International Scientific
Meeting on The Boreal Forests of the World, Jokkmokk, Sweden, 30/9/92-2/10/92,
published by the Taiga Rescue Network, Jokkmokk, Sweden.
return to text
17. Winjum.J.K, Dixon.R.K & Schroeder.P.E,
(1992), Conservation and sequestration of carbon; the potential of
forest and agroforest management practices, Global Environmental
Change, June 1993, pp159-173, Butterworth-Heinemann Ltd.
return to text
18. Finnish Forestry Association, (1993),
PlusForest Bulletin 1993, Finnish Forestry Association, Helsinki, Finland.
return to text
19. Harmon et al, (1990), Op Cit.
return to text
20. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
21. Kauppi.P.E & Tompo.E, (1993), Impact
of Forests on Net National Emissions of Carbon Dioxide in West Europe,
Water Air & Soil Pollution 70: pp197-196. 1993, Kluwer Academic
Publishers.
return to text
** Throughout the briefing, the term forestation refers
to both afforestation and reforestation (see glossary).
return to text
22. FAO Forestry Department, (1991), Climate
Change and Global Forests: Current Knowledge of Potential Effects, Adaptation
and Mitigation, in proceedings from the Technical Workshop to
Explore Options for Global Forestry Management, Bangkok 1991, IIED.
return to text
23. Houghton.R.A, Unruh.J & Lefebvre.P.A,
(1991), Current Land Use in the Tropics and its Potential for Sequestering
Carbon, in proceedings from the Technical Workshop to Explore
Options for Global Forestry Management, Bangkok 1991, IIED.
return to text
24. Winjum.J.K, Dixon.R.K & Schroeder.P.E,
(1992), Estimating the Global Potential of Forest and Agroforest
Management Practices to Sequester Carbon, Water Air & Soil Pollution
Vol.64 Nos 1/2 pp213-227, Kluwer Academic Publishers.
return to text
25. Calculations based on the figures of 7
tonnes of carbon hectare-1 year-1 for the
average carbon uptake of a fast growing tropical plantation quoted in
Grayson.A.J, (1989), Carbon Dioxide, Global Warming and Forestry,
Forestry Commission Research Information Note 146, Forestry Commission,
UK, and the figure of 2.2 tonnes of carbon hectare-1 year-1
for Canadian boreal forest plantation quoted in Canadian Pulp &
Paper Association, (1991), Global Climate Change; A Statement by
the Pulp & Paper Industry, Canadian Pulp & Paper Association,
Montréal, Canada.
return to text
26. Houghton.J.T et al (eds), (1995), Climate
Change 1994; An Evaluation of the IPCC IS92 Emissions Scenarios,
Cambridge University Press for the Intergovernmental Panel on Climate
Change.
return to text
27. 1990 carbon emissions = 6.1 billion tonnes.
Converted from (using a conversion factor of 3.66) a CO2
emissions figure of 22.34 billion tonnes quoted in; World Resources
Institute, United Nations Environment Programme, World Bank, United
Nations Development Programme, (1996), World Resources 1996-97,
Oxford University Press, Oxford, UK. A 1% per annum increase means that
1997 carbon emissions are about 6.5 billion tonnes. A 2.39% increase
means that 1997 carbon emissions are about 7.1 billion tonnes.
return to text
28. Food and Agriculture Organisation (FAO),
(1997), Op Cit.
return to text
29. Using an average figure for temperate
forests of 5.5 tonnes of carbon hectare-1 year-1
taken from Kiebitsch et al, (1992), Temperate amd Boreal Forests,
Section 5 of the Draft Contribution to the 1992 Intergovernmental Panel
on Climate Change Supplement - Task 4: Forestry Related Issues, IPCC
Secretariat, Geneva, Switzerland.
return to text
30. Skogsindustrierna, (29/10/93), Press Release
- Nordic forests slow down the greenhouse effect, Skogsindustrierna,
Stockholm, Sweden.
return to text
31. Suback.S, Craighill.A, Guthrie.M &
Kelly.M, (1996), The Paper Industry and Global Warming. No.20
in Towards a Sustainable Paper Cycle Sub-Study Series, IIED, UK.
return to text
32. Calculation based on a figure of 1.7 tonnes
ha-1 yr-1 for lowland Scots pine in the UK
quoted in Thompson.D.A & Matthews.R.W, (1989), Op Cit.
return to text
33. Calculation is based on an annual UK carbon
emission figure of 154.7 million tonnes taken from a CO2
emission figure of 566.2 million tonnes quoted in World Resources Institute
et al, (1996), World Resources 1996-97, Oxford University Press,
Oxford, UK.
return to text
34. Between 1990 and 1994, 41,000 hectares
of forest was planted (an average of 10,250 hectares per annum) quoted
in Department of the Environment, (1995), Digest of Environmental
Statistics, Government Statistical Service, London.
return to text
35. Larrman.J.G & Sedjo.R.A, (1992), Global
Forests; Issues for Six Billion People, McGraw-Hill Inc, USA.
return to text
36. FAO Forestry Department, (1991), Climate
Change and Global Forests: Current Knowledge of Potential Effects, Adaptation
and Mitigation, in proceedings from the Technical Workshop to
Explore Options for Global Forestry Management, Bangkok 1991, IIED.
return to text
37. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
38. Rosoman.G, (1994), The Plantation Effect;
An Ecoforestry Review of the Environmental Effects of Exotic Monoculture
Plantations In Aotearoa/New Zealand, Greenpeace New Zealand, Auckland,
New Zealand.
return to text
39. Organisation for Economic Cooperation
and Development (OECD), (1991), State of the Environment, OECD,
Paris.
return to text
40. Barnett.A, (1992), Deserts of Trees;
The Environmental and Social Impacts of Large-Scale Tropical Reforestation
in Response to Global Climate Change, Friends of the Earth Trust
Ltd, London.
return to text
41. Hansson.L (ed), (1992), Ecological
Principles of Nature Conservation; Applications in Temperate and Boreal
Environments, Elsevier Applied Science, London & New York.
return to text
42. Barnett.A, (1992), Op Cit.
return to text
43. FAO Forestry Department, (1991), Op
Cit.
return to text
44. Hadfield.P, (1997), Op Cit.
return to text
45. Nuttall.N, (1997), Op Cit.
return to text
46. International Energy Agency (IEA) Greenhouse
Gas R&D Programme, (1997), Annual Report 1996, IEA Greenhouse
Gas R&D Programme, Cheltenham, UK.
return to text
47. Assuming that; the unmanaged old-growth
forest contains twice as much stored carbon as a managed forest harvested
on a 100 year rotation (Harmon et al, 1990, op cit), that less than
half of the harvested biomass is converted into timber/paper (Suback.S
et al, 1996, op cit) and that most of the timber and paper will have
released the stored carbon within a couple of centuries.
return to text
48. Skogsindustrierna, (1995), In Balance
with Nature, Skogsindustrierna, Stockholm, Sweden and Skogsindustrierna,
(29/4/94), Swedish Forests Bind Greenhouse Gases, press release.
return to text
49. Swedish Pulp & Paper Association et
al, (1994), Scandinavian Forestry, Swedish Pulp & Paper Association,
Svensk Skog, Norwegian Pulp & Paper Association, The Norwegian Forest
Owners' Federation, Finnish Forest Industries Federation, Finnish Forestry
Association, Nordic Timber Council.
return to text
50. Swedish Pulp & Paper Association et
al (1994), Op Cit.
return to text
51. International Institute for Environment
and Development, (1996), Towards a Sustainable Paper Cycle, IIED,
London.
return to text
52. MoDo Paper UK Ltd, (1990), Recycled
Paper; Uses and Abuses, MoDo Paper UK Ltd, Surrey, England.
return to text
53. Finnish Forestry Association, (1993),
Op Cit.
return to text
54. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
55. Resource Assessment Commission, (1992),
Forest and Timber Inquiry - Final Report Volume 1, Australian
Government Publishing Service, Canberra, Australia.
return to text
56. Gorgolewski.M, (1997), Steel Framed
Housing, an Environmental Option?, Building for a Future, Vol.7
No.1, Spring 1997, pp24-27. Figures of 26-40 GJ/tonne for primary steel
and 9 GJ/tonne for recycled steel were quoted in this article. A rough
conversion factor of 277.76 was used to obtain kWh/tonne figures.
return to text
57. Resource Assessment Commission, (1992),
Op Cit.
return to text
58. Trexler.M & Haugen.C, (1995), Op
Cit.
return to text
59. Kürsten.E & Burschel.P, (1993),
CO2 Mitigation by Agroforestry, Water Air
& Soil Pollution 70 Nos 1/4, pp533-544, Kluwer Academic Publishers.
return to text
60. Winjum.J.K, Dixon.R.K & Schroeder.P.E,
(1992), Conservation and sequestration of carbon; the potential of
forest and agroforest management practices, Global Environmental
Change, June 1993, pp159-173, Butterworth-Heinemann Ltd.
return to text
61. Trexler.M & Haugen.C, (1995), Op
Cit.
return to text
62. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
63. Scurlock.J.M.O et al, (1993), Utilising
Biomass Crops as an Energy Source: A European Perspective, Water
Air and Soil Pollution Vol.70 Nos.1/4, October 1993 pp499- 518, Kluwer
Academic Publishers.
return to text
64. Rosillo-Calle.F & Hall.D.O, (1992),
Biomass Energy, Forests and Global Warming, Energy Policy, February
1992.
return to text
65. Leemans.R et al, (1996), The land cover
and carbon cycle consequences of large-scale utilizations of biomass
as an energy source, Global Environmental Change, Vol.6 No.4 pp335-357.
return to text
66. Scurlock.J.M.O et al, (1993), Op Cit.
return to text
67. Leemans.R et al, (1996), Op Cit.
return to text
68. ETSU, (1996), Good Practice Guidelines;
Short Rotation Coppice for Energy Production. The Development of an
Economically and Environmentally Sustainable Industry, ETSU, November
1996.
return to text
69. Woodwell.G.M in Sharma.N.P (ed), (1992),
Managing the World's Forests; Lookin for a Balance Between Conservation
and Development, pp75-91, Kendall Hunt, USA.
return to text
70. Woodwell.G.M in Sharma.N.P (ed), (1992),
Op Cit.
return to text
71. Brown.S et al, (1993), Op Cit.
return to text
72. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
73. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
74. Watson.R.T et al (eds), (1996), Op
Cit.
return to text
75. Calculation based on figures published
in Watson.R.T et al (eds), (1996), Op Cit.
return to text
76. Trexler.M & Haugen.C, (1995), Op
Cit.
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August 1997
Peter Hardstaff
Last modified: December 2001
