sinks

key points

introduction

contradictions

significant uncertainty

plantation threat to primary old-growth forest

stores and sinks

carbon fertilisation

long term security

clean development mechanism

accounting under the cdm

economic distortions

recommendations

notes and references

‘the type of forest needed to control the greenhouse effect is different from that needed to nurture biodiversity...In terms of controlling the greenhouse effect, forests should be regenerated, and more made of timber as a raw material'

Finnish Forest Industries Federation 1995

‘Terrestrial sinks are by no means constant. Even slight climate changes can lead to sinks becoming sources.'

German Advisory Council on Global Change 1998

key points

Annex 1 Parties to the Convention on Climate Change are looking to biological sinks as a way of offsetting, or reducing, their carbon dioxide emissions. Given the considerable associated uncertainties, and the potential for sinks to become sources, no decisions should be taken on sinks before IPCC's Special Report on landuse change and forestry has been completed.

Friends of the Earth International supports measures which will encourage the conservation of sinks in both developed and developing countries. High biomass, old-growth forests must be protected in order that climate biodiversity and indigenous forest peoples are also protected.

However, sinks must not be included in projects under the Clean Development Mechanism (CDM) until the risk of perverse incentives to deforest indigenous forests and replace these with fast-growing plantations has been limited.

introduction

Changes in the way forests are managed are gaining popularity as a means of offsetting or reducing emissions of carbon dioxide into the atmosphere [1]. Nations that agreed to reduce their greenhouse gas emissions at Kyoto in December 1997 are already examining options in forest management to sequester and store carbon rather than reducing emissions at source. These include reforestation, afforestation, agroforestry and urban forestry.

Widescale scientific concensus now exists that the major contributor to climate change is carbon dioxide from fossil fuel burning [2]. Common sense would have us reduce emissions at source. However because certain ecosystems such as forests remove CO2 from the atmosphere during photosynthesis, acting as sinks, the Kyoto Protocol allows Parties to meet their emission reduction commitments through both reduction of emissions at source and the expansion of sinks.

In theory the establishment of a sink as a carbon credit allows the greenhouse polluter to emit an amount of CO2 equal to the amount of CO2 the sinks absorbs, without the original emission having an impact on the atmosphere.

contradictions

However, the whole notion that emissions from industrial sources go into the atmosphere and are then neatly deposited upon the desired plantation thousands of miles away is hopelessly linear in a climatic system that is as dynamic as it is unpredictable.

Given that trees being planted in new sinks and re-vegetation programmes today are not even making up for the carbon dioxide released from the clearing of trees historically and continuing to this day one can question how appropriate it is that tree-planting should be used to offset the CO2 emitted from fossil fuel burning [3]. And saving an existing forest is a future emission avoided not an action that reduces existing emissions.

Furthermore the carbon released by fossil fuel burning was deposited over geological time scales yet it is being expected that forests, whose lifetime can scarcely be guaranteed over several centuries, will provide an effective solution to the rapid increase in greenhouse gas emissions currently taking place.

Despite all these contradictions sinks have been included in the Protocol and the question now is how to ensure that they do not undermine the Climate Convention, nor threaten biodiversity.

Article 3.3 of the Kyoyo Protocol provides that: "The net changes in greenhouse gas emissions by sources and removals by sinks resulting from direct human-induced land-use change and forestry activities, limited to afforestation, reforestation and deforestation since 1990, measures as verifiable changes in carbon stocks in each commitment period, shall be used to meet the commitments under this Article of each Party included in Annex 1. The greenhouse gas emissions by sources and removals by sinks associated with those activities shall be reported in a transparent and verifiable manner and reviewed in accordance with Articles 7 and 8."

signifcant uncertainty forward

The use of sinks to offset against emission reduction commitments was a very contentious issue at Kyoto, not least because of major uncertainties in measuring the removal of atmospheric carbon dioxide by sinks.

Although sinks were included in the Protocol it was decided in subsequent negotiations held in Bonn June 1998 that these uncertainties warrented a special report by the Intergovernmental Panel on Climate Change (IPCC). This will be ready in 2001. The most recent IPCC report on this topic published in 1995 stated that there were many uncertainties involved in working out how much carbon can be taken up by forests globally. These uncertainties include:

• The amount of land available and suitable for tree planting projects

• The long-term security of forests as a store of carbon

• The viability of some forestry activities in certain regions due to the effects of climate change.

plantation threat to primaryold-growth forest

Young trees absorb carbon dioxide (CO2) at a faster rate than mature trees and carbon in old trees can be locked away for a long time if the wood is used for long-lasting timber products rather than burnt or left to decompose. Add these two facts together and one has a climate strategy that is winning converts among forestry authorities, the forest products industry and policy-makers alike. "Carbon dioxide is kept out of the atmosphere by harvesting the forest before it begins to decompose or burn," explains Don Young, Chairman of the US (Alaska) House Resources Committee, "thus storing the carbon in wood products that are environmentally friendly, as well as providing an economic benefit to society" [4]. It makes most environmental sense, US lawmakers claim, "to cut down matures forests which are no longer growing quickly and replace them with vigorous saplings which bulk up faster"[5]. Of all the biomes, the tropics, the IPCC believes, has the potential to conserve and sequester by far the largest amount of carbon [6]. For this reason and, of course, the cheap overhead costs, tropical areas will undoubtedly be the focus for plantation development. A number of issues arise from this possibility:

• Will the plantation fix more carbon than that lost by deforestation of a mature rainforest?

• Will there be unaccounted for negative effects of deforestation such as negative impacts on indigenous peoples, biodiversity, water loss, soil erosion?

stores and sinks

Looking at the first question, it is estimated that up to two-thirds of the carbon stored in mature forests is released into the atmosphere upon deforestation [7]. To what extent this can be minimised depends on the species used in the plantations, their relationship with the climate and ecosystem and how long timber products from the deforested mature forest will last.

Views vary widely as to the comparative carbon sequestration efficiency of plantations versus natural forest and tend to depend on which methodology is used to evaluate carbon sequestration potential [8]. Studies with multiple aims encompassing biodiversity conservation and carbon storage potential reveal that the best option is to protect the existing forest rather than replace it with plantation. Studies whose sole focus is on carbon sequestration will tend to favour replacement of natural forest with plantations.

The question of time is a key consideration. A comparison of plantations with any other forest type that fails to consider time is meaningless. This is because the rotation period for harvesting timber is a key factor in the ability of plantations to remove carbon from the atmosphere over the long-term [9]. Many rotation periods do not come close to optimising carbon uptake by plantations. For example, plantation species used to produce paper may have rotation periods of 12-15 years, negating the possibility of long-term carbon storage.

carbon fertilisation

Arguments in favour of carbon sequestration projects have raised the issue of additional benefits plantations will receive from increasing levels of CO2. It is thought that under high levels of atmospheric carbon associated with climate change, young trees will thrive to a much greater extent than mature forests.

There is little argument that increased levels of CO2 will stimulate plant growth rates, particularly when carbon is the limiting factor, under experimental conditions. However, there are serious doubts that this would be the case in the field [10] e.g.

• Nutrient limitations may reduce growth response to elevated CO2 presenting a long-term constraint.

• Increased atmospheric CO2 can cause reduced uptake through photosynthesis.

• Increased input of carbon in the soil can lead to progressive immobilisation of nutrients in the soil and hence, decreased nutrient uptake [11].

• Reduced nutrient uptake coupled with increased CO2 fixation will lower the amount of nitrogen in the leaves (lowering the N:C ratio). This, in turn, may lower net primary productivity since photosynthesis is positively correlated with foliage nitrogen content [12].

In addition, a decrease of nitrogen in the foliage means reduced leaf protein on the whole. One consequence is that pests will need to consume more vegetation to acquire adequate protein levels. Add to this the predicted increase, under climate change, in frequency of outbreaks and extended range of pests and pathogens in forests, and the expected increase in plant production becomes even more uncertain.

long term security

The question as to whether forests will continue as carbon sinks in the future depends on the relative temperature sensitivity of forest species and the rate of decomposition of soil organic matter. Climate models that combine the effects of elevated CO2 (from 290-354 ppmv) and temperature (+0.5 C) for the period 1960-1990 show a decrease in carbon storage in the high latitude boreal forests of Canada and Russia, for example. Such is the extent of warming that Canadian forests have gone from being a net sink for CO2 to a source in two decades [13]. The stark reality is that climate change could result in sinks becoming sources.

Tropical forests are extremely sensitive to changes in the amount of moisture and its seasonal distribution [14]. The fact that precipitation is predicted to increase in some areas does not mean that regional precipitation will also increase. Nor does it mean that its pattern will be constant. The IPCC points out that regional changes in precipitation may not provide enough to meet the increased demand for water due to the effects of increased temperatures on evapotranspiration. The deforestation of significant tropical areas will undoubtedly reduce that region's precipitation. Evidence also suggests that rising temperatures will lower watertables, making water, in some areas, a limiting factor to growth [15]. This could be more problematic for boreal regions than tropical areas where the effects of warming are predicted to be most severe.

The longevity of any forest project is in doubt when one considers the predicted impact of climate change on shifting ecosystems. Deserts are expected to expand, tropical ecosystems are predicted to move towards temperate regions and temperate ecosystems will move into boreal ones. The rate of poleward movement could be as much as 100 km per decade by the middle of next century. Most tree species migrate at best at only one-tenth of this speed.

In summary, while fast-growing plantations benefit from high levels of CO2, particularly in the tropics, there is little evidence to suggest that they will benefit more than mature forests from the various changes produced by climate change. In fact, evidence suggests that deforestation, especially of tropical forests, makes a region more susceptible to climate change damage. Added to these risks and uncertainties is the possible inclusion of sinks in one of the flexible mechanisms created by the Kyoto Protocol - the Clean Development Mechanism (CDM).

clean development mechanism

Under Articles 3 and 12 of the Kyoto Protocol, a developed country may offset its emissions by creating or enhancing a sink in a developing country. Under this procedure, known as the Clean Development Mechanism (CDM), a rainforest can, for instance, be sold for its carbon sink capacity in exchange for cash from a developed country.

The kind of changes in land-use that can be included in the CDM are still uncertain. At present, afforestation, deforestation and reforestation since 1990 may be included, but no further criteria have been established. Significantly, the status of forests potentially subject to the CDM has yet to be discussed. The urgent call from the IPCC to protect high biomass, old-growth forests has not yet been answered in the form of mandatory protection of such forests.

This is of particular concern given their role in climate regulation and their significance for biodiversity. At present, the best protection lies in distantly related international agreements such as the Convention on Biological Diversity (1992) and the CITES conventions. These agreements forbid, among other activities, the use of certain products from tropical forests. The extent of the forests protected, however, is still small. Currently, about 12% of the tropical forests in Latin America and the Caribbean are subject to international protection of one form or another. In Asia and Africa, international protection extends to about 14% and 5% of tropical forests respectively [16].

accounting under the cdm

Currently only countries listed under Annex 1 have commitments to reduce emissions. This raises a potential problem when one considers the CDM. Developing countries do not have commitments and do not have to account for emissions. It is therefore possible that a developing country could clear-cut a forest and then sell emission credits to a developed country on the basis of re-planting [17]. As long as developing countries do not have to meet any commitments it must be ensured that any emissions from any clearcutting would be accounted to the industrialised country. Additionally, in the absence of full carbon accounting for developing countries forest conservation in one place may just lead to deforestation in another part of the country - a process known as leakage.

economic distortions

Bias in the evaluation of forest resources can make a carbon sequestration project appear more financially lucrative than the conservation of an indigenous forest. Consider the following scenario:

A developing country in the tropics contains large areas of rainforest. These areas generate income from eco-tourism and from indigenous use of forest products, but, aside from environmental functions, contribute little to the country's GDP. In consequence, the forest is assigned a relatively low monetary value. The country is approached by an industrial country which, under the Clean Development Mechanism, seeks to offset some of its CO2 emissions by enhancing the carbon sink capacity in the rainforests. If it accepts the proposal, the developing country is faced with several options, two of which are addressed below:

1) The developing country could sell areas of the rainforest as a carbon credit function in return for cash or debt relief. Current estimates of the value of sequestered carbon range from US$12tC-US$40tC [18]. Since most rainforests are more or less in a carbon equilibrium, the sequestration rate ranges from a low average 0.5 tC ha-1 yr-1 to, at best, 2-4 tC ha-1 yr-1, one hectare of rainforest could be assigned an additional value of between US$24-US$120 (using the higher sequestration rate). (Estimates of total economic worth of tropical rainforests are extremely variable. For example, the net economic benefit of conserving a tropical rainforest (excluding its carbon credit function) in Cameroon ranges from US$1,000,000-US$12,320,000 [19], depending upon factors chosen for evaluation and how these factors are valued.

To offset the emissions from a 500 MWe coal-fired power station (some 0.8 Mt C yr-1) would require a tropical rainforest area of between 200,000 ha and 400,000 ha with an optimum sequestration rate of 2-4 tC ha-1 yr-1 (regrowing, selectively logged forest). The cost of offsetting this amount of C, on the basis of forest area purchased for the life of the power station, could cost between US$4,800,000- US$48,000,000 (200,000 ha times US$24- 400,000 ha times US$120 ha) a significant enhancement of a national asset for a developing country but an expensive option for carbon emitters.

2) A second option is to deforest areas of the rainforest to make way for fast-growing plantations. A plantation of Acacia mearnsii, for example, sequestering carbon at a rate of up to 7.8 tC ha-1 could offset the 0.8 MtC yr-1 from the power station with little over 102,500 ha of plantation - a quarter to one-third of the area needed by the rainforest. At a cost of roughly US$230 ha of plantation, [20] this area could cost around US$23,575,000 - a preferable option for the carbon emitter.

If the conservation of a rainforest is considered to provide either low economic benefits for the recipient country or to be too expensive to offset carbon for the carbon emitter, then plantations can, by appearing cheaper than the rainforest option but costly enough to provide the recipient country with considerable income, be seen to be the economically preferable option to rainforest conservation. They appear preferable primarily because of the wide variation in the value assigned to the rainforests (as the Cameroon example indicates).

Yet the conservation of rainforests brings numerous financial benefits in terms of products and services which may not be adequately accounted e.g. non-timber products such as latex, resin, honey, rattan etc, creation, medicine, plant genetics, education and human habitat. There are also items that provide indirect use such as the forest's role in nutrient cycling, watershed protection, prevention of soil erosion and cultural heritage. It is clear, however, that items which have an ‘indirect use value' cannot be easily quantified in monetary terms. Attempt to do so are invariably based on speculative economic tools such as contingent evaluation and cost-benefit analysis.

The problems in the use of such evaluative economic tools are twofold. On the one hand, there is an inherent bias of market over non-market resources and, on the other, an assumption that all values can, in principle, be reduced to monetary values. The bias often results in the benefits of development projects outweighing those of conservation on a scale tilted in favour of development in the first place. The assignment of values to resources will remain relative to the evaluator's interests, "forest policy and forest management are determined primarily by economic considerations" [21], considerations which are themselves based on a short-term profit-based outlook.

Given the variability in the financial worth assigned to forests, this factor coupled with the current lack of protection for indigenous forests, could see the creation of perverse incentives under the Kyoto Protocol to deforest indigenous forests and replace these with fast-growing plantations if it can be shown that the latter are more efficient at reducing levels of atmospheric carbon.

recommendations

The Conference of Parties to the Climate Convention and the Kyoto Protocol must ensure that decisions on sinks serve to both conserve biodiversity and protect or create carbon sinks. Measures should include the conservation of wetlands and primary forests which represent large, stable stores of carbon. Afforestation programmes should be encouraged on degraded areas no longer suitable for agriculture. This would, in part, help to protect the climate and conserve soils and biodiversity.

No decisions should be taken on sinks before the IPCC's Special Report on landuse change and forestry has been completed. This will provide an in-depth study of methodological and ecological implications of accounting biological sources and sinks. Questions as to the long term security of sinks must be addressed.

Friends of the Earth International supports measures which will encourage the conservation of sinks in both developed and developing countries. However, there is a danger that the CDM could create a perverse incentive to clear-cut forests in developing countries, if reforestation measures are financed without previous deforestation accounted. This must be prevented and sinks must not be included in the CDM until this problem is resolved.

notes and references

[1] Marland, G. (1988). The prospects of solving the CO2 problem through global afforestation. Report for the US Department of Energy. Oak Ridge National Laboratory Report DOE/NBB-0082. Oak Ridge National Laboratory, Oak Ridge, TN, 66p. Sedjo, R (1989). Forests to offset the greenhouse effect. Journal of Forestry 87, pp12-15. Thompson, D and Matthews, R. (1989). The storage of carbon in trees and timber. Forestry Commission Research Information Note 160. Forestry Commission, Edinburgh, Scotland.

[2] 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. Cambridge University Press, Cambridge, UK.

[3] Reynolds, A and Curley E (1998) Planting trees for climate change - is it the answer? Discussion paper. Australian Conservation Foundation, Sydney.

[4] Young in Cushman, J.H. Jr. (1998). Can trees mitigate the greenhouse effect? The International Herald Tribune 9 March, 1998, pp12.

[5] Cushman (1998). Op cit.

[6] Watson, R.T. et al (eds) (1996). Op cit. pp784.

[7] Cannell, M. (1995). Forests and the Global Carbon Cycle in the Past, Present and Future. European Forest Institute, pp23.  

[8] Matthews, R. (1996). The influence of carbon budget methodology on assessments of the impacts of forest management on the carbon balance in Apps, M and Price, D (eds) (1996). Forest Ecosystems, Forest Management and the Global Carbon Cycle 1, 40. Springer-Verlag, Berlin pp233-243.

[9] Schroedor, P (1992) Carbon storage potential of short rotation tropical tree plantations. Forest Ecology and Management 50, pp31-41.

[10] Luxmoore et al (1993) op cit. Arp, W. (1991) effects of source-sink relations on photosynthetic acclimation to elevated CO2. Plant, Cell and Environment 14, pp869-875. Korner, C. (1993) CO2 fertilisation: the great uncertainty in future vegetation development in Solomon, A. Et al (eds). Vegetation Dynamics and Global Change. Chapman and Hall, London 1993, pp53-70.

[11] Cannel (1995) op cit pp31.

[12] Comins, H. And McMurtie, R (1993). Long-term biotic reponse of nutrient-limited forest ecosystem to CO2-enrichment: equilibrium bahavious of integrated plant-soil models. Ecological Applications 1, pp 666-681.

[13] Apps in Riemer, P et al (1998) op cit.

[14] Myers, N. (1984). The Primary Source. Norton, London, pp41.

[15] Oechel, W et al (1993) Recent changes of arctic tundra ecosystems from a net carbon dioxide to a source. Nature 361, pp520-526.

[16] FAO (1995). State of the World's Forests. Food and Agricultural Organisation of the United Nations, Rome.

[17] German Advisory Council on Global Change (1998). The Accounting of Biological Sinks and Sources under the Kyoto Protocol - A Step Forwards or Backwards for Global Environmental Protection?

[18] Watson, R et al (1996) op cit pp599; Tipper, R. (1998). Assessing the cost of large scale forestry for CO2 sequestration in southern Mexico in Reimer, P (1998) op cit

[19] Barbier, E. (1991) Tropical Deforestation in Pearce, D (1991). Blueprint 2: Greening the World Economy. Earthscan, pp148-153. Pearce, D. (1995) op cit. Peters, C. et al (1989) Valuation of an Amazonian Rainforest in Nature 339, 29 June 1989, pp655-6

[20] Watson, R. et al. (1996). Op cit. Pp. 786.

[21] Matthews, R. Et al (1996) in Apps and Price (1996), pp300. Brown, P. et al (1997). Carbon Counts: Estimating Climate Change Mitigation Forestry Projects. World Resources Institute, Washington D.C.

© Friends of the Earth International, 1998

This briefing is based on a paper by Paul Anderson of the University of Edinburgh prepared for Friends of the Earth Scotland

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