Assessment of GHG inventories from the LUCF sector of Annex-I countries

Reporting of CO₂ emissions and removals from the landuse change and forestry (LUCF) sector is assessed in this paper based onthe National GHG inventories and the National Communications submittedby the Annex-I countries. LUCF sector is a net sink for 27 countries outof 31 countries and a source for Australia, Estonia, Lithuania and UnitedKingdom. LUCF sector for Annex-I countries, as a group is a net sink of2035 Tg CO₂ (555 Tg Carbon). The sink feature is largely due toCO₂ removal by the existing forests, plantations and other trees.Forest and grassland conversion (deforestation) is not a major source ofCO₂ in the Annex-I countries. Many Annex-I countries have notfully adopted the reporting format of IPCC limiting the comparability andtransparency. Several Annex-I countries have modified the CO₂emission/removal estimates for 1990, but have not explained the reasons.Reporting of uncertainty is very limited. The methods adopted andparticularly reporting is inadequate to meet the requirements foroperationalising the Kyoto Protocol articles relevant to LUCF;comparability, transparency and verifiability.     

The Kyoto Protocol could make a difference for the optimal forest-based CO2 mitigation strategy: some results from GORCAM

The Kyoto Protocol was agreed on by more than 150 nations in December, 1997 and (if and when ratified) will establish international commitments to reduce emissions of greenhouse gases to the atmosphere. Under the Kyoto Protocol, some of the carbon emissions and removals within the land-use change and forestry sector can be counted toward a country's commitments for greenhouse gas emissions reductions. In addition to the impacts that land-use practices have on CO₂ emissions from fossil-fuel combustion, changes in the carbon stocks of forests (possibly including forest soils) caused by the direct human activities afforestation, reforestation and deforestation and taking place in the `first commitment period' (2008–2012), are to be accounted for under the Kyoto Protocol. Credits for carbon sinks in the biosphere are limited to projects initiated since 1990. A modified version of the model GORCAM has been used to assess eligible emission-reduction credits under the Kyoto regime and to illustrate how the optimal forest-based strategy for carbon dioxide mitigation might change under the provisions of the Kyoto Protocol. The Kyoto Protocol offers rewards for only some of the changes in carbon stocks that might occur and hence the forestry project that produces the most emission reduction credits under the Kyoto Protocol is not necessarily the same project that produces the greatest benefit for net emissions of carbon dioxide to the atmosphere. Supplementing the Protocol with appropriate definitions, interpretations and agreements could help to make sure that it does not provide incentive for activities that run counter to the objectives of the Framework Convention on Climate Change.     

Land-use change in Australia and the Kyoto Protocol

In the dying hours of the Kyoto Climate Change Conference, the negotiators agreed to the insertion of the `Australia clause' in Article 3.7. The clause permits countries for which land-use change and forestry are a net source of greenhouse gas emissions to include net emissions from land-use change in their 1990 base year for the purpose of calculating assigned amounts or targets for the commitment period 2008–2010.This clause applies effectively to Australia alone amongst industrialised (Annex 1) countries, but it may have major implications for the negotiated targets of developing countries.This paper uses the official inventories to describe the comprehensive emissions situation for Australia. In the process it discusses the various methodological and data uncertainties associated with measuring emissions from land-use change.It is shown that emissions from land-use change in the 1990 base year were 89.8 Mt or 18.9% of Australia's total comprehensive emissions. By 1996 this had declined to 62.8 Mt, probably as a result of the falling profitability of land clearing for cattle grazing.The paper then considers the likely path of emissions from land use change through to the commitment period 2008–2012 and how this affects allowable emissions from the energy and other sectors. Two scenarios are described. Scenario 1 assumes that the rate of land clearing does not change from the rate in 1996, while scenario 2 assumes that the Australian Government implements its announced plan to cut land clearing by 20,000 ha/a starting in the year 2000. Under scenario 1, Australia's fossil energy (and other non-land-use) emissions can increase by 20%, while under scenario 2, fossil emissions will be able to increase by 26% by 2008–2010.     

Article 3.3 and 3.4 of the Kyoto Protocol: consequences for industrialised countries’ commitment,the monitoring needs,and possible side effects

In the Kyoto Protocol, industrialised countries have agreed to reduce their carbon dioxide emissions. To achieve that target, direct human induced activities initiated in the Land-use Change and Forestry sector since 1990, shall be included. However, the wording in the Protocol has caused confusion. The IPCC has been requested to deliver a Special Report on Land-use, Land-use Change and Forestry issues arising from this Protocol. In the present study a limited initial assessment of the implications of alternative interpretations of Afforestation, Reforestation and Deforestation (ARD), addition of the soils compartment, the selection of additional activities, and feasibility of monitoring was done for a limited number of countries.The results show that it is possible to keep the biosphere articles in the Protocol even though we had to make several assumptions concerning for example, areas of application and effectiveness of additional activities. The consequences of alternative interpretations for ARD have a large impact on the countries’ assigned amount; varying from a compensation of 26% of total national emissions (Forestry interpretation for Sweden) to an addition of an extra 13% of the emissions (Global interpretation for Australia). Through selection of a large set of additional activities, most of the studied industrialised countries achieve more sequestration than the reduction of emissions they have committed themselves to. Methods for monitoring are available, but there is no one ideal method. Depending on scale and site: a combination of forest inventory with flux measurements and remote sensing is proposed.     

Land Use,Land-Use Change,Forestry, and Agricultural Activities in the Clean Development Mechanism: Estimates of Greenhouse Gas Offset Potential

Activities involving land use, land-use change,forestry, and agriculture (LUCF) can help reducegreenhouse gas (GHG) concentrations in the atmosphereby increasing biotic carbon storage, by decreasing GHGemissions, and by producing biomass as a substitutefor fossil fuels. Potential activities includereducing rates of deforestation, increasing landdevoted to forest plantations, regenerating secondaryforest, agroforestry, improving the management offorests and agricultural areas; and producing energycrops.Policymakers debating the inclusion of a variety ofLUCF activities in the Clean Development Mechanism(CDM) of the Kyoto Protocol need to consider themagnitude of the carbon contribution these activitiescould make. Existing estimates of the cumulative GHGoffset potential of LUCF activities often take aglobal or regional approach. In contrast, land-usedecisions are usually made at the local level anddepend on many factors including productive capacityof the land, financial considerations of thelandowner, and environmental concerns. Estimates ofGHG offset potential made at a local, or at mostcountry, level that incorporate these factors may belower, as well as more useful for policy analyses,than global or large regional estimates. Whilecountry-level estimates exist for forestry activities,similar estimates utilizing local information need tobe generated for agricultural activities and biofuels,as well as for the cumulative potential of all LUCFactivities in a particular location.     

Accounting for time in Mitigating Global Warming through land-use change and forestry

Many proposed activities formitigating global warming in the land-use change and forestry(LUCF) sector differ from measures to avoid fossilfuel emissions because carbon (C) may be held out ofthe atmosphere only temporarily. In addition, thetiming of the effects is usually different. Many LUCFactivities alter C fluxes to and from the atmosphereseveral decades into the future, whereas fossil fuelemissions avoidance has immediate effects. Non-CO₂ greenhouse gases (GHGs), which are animportant part of emissions from deforestation inlow-latitude regions, also pose complications forcomparisons between fossil fuel and LUCF, since themechanism generally used to compare these gases(global warming potentials) assumes simultaneousemissions. A common numeraire is needed to expressglobal warming mitigation benefits of different kindsof projects, such as fossil fuel emissions reduction,C sequestration in forest plantations, avoideddeforestation by creating protected areas and throughpolicy changes to slow rates of land-use changes suchas clearing. Megagram (Mg)-year (also known as`ton-year') accounting provides a mechanism forexpressing the benefits of activities such as these ona consistent basis. One can calculate the atmosphericload of each GHG that will be present in each year,expressed as C in the form of CO₂ and itsinstantaneous impact equivalent contributed by othergases. The atmospheric load of CO₂-equivalent Cpresent over a time horizon is a possible indicator ofthe climatic impact of the emission that placed thisload in the atmosphere. Conversely, this index alsoprovides a measure of the benefit of notproducing the emission. One accounting methodcompares sequestered CO₂ in trees with theCO₂ that would be in the atmosphere had thesequestration project not been undertaken, whileanother method (used in this paper) compares theatmospheric load of C (or equivalent in non-CO₂GHGs) in both project and no-project scenarios.Time preference, expressed by means of a discount rateon C, can be applied to Mg-year equivalencecalculations to allow societal decisions regarding thevalue of time to be integrated into the system forcalculating global warming impacts and benefits. Giving a high value to time, either by raising thediscount rate or by shortening the time horizon,increases the value attributed to temporarysequestration (such as many forest plantationprojects). A high value for time also favorsmitigation measures that have rapid effects (such asslowing deforestation rates) as compared to measuresthat only affect emissions years in the future (suchas creating protected areas in countries with largeareas of remaining forest). Decisions on temporalissues will guide mitigation efforts towards optionsthat may or may not be desirable on the basis ofsocial and environmental effects in spheres other thanglobal warming. How sustainable development criteriaare incorporated into the approval and creditingsystems for activities under the Kyoto Protocol willdetermine the overall environmental and social impactsof pending decisions on temporal issues.     

Developing Canada's National Forest Carbon Monitoring, Accounting and Reporting System to Meet the Reporting Requirements of the Kyoto Protocol

The rate of carbon accumulation in the atmosphere can be reduced by decreasing emissions from the burning of fossil fuels and by increasing the net uptake (or reducing the net loss) of carbon in terrestrial (and aquatic) ecosystems. The Kyoto Protocol addresses both the release and uptake of carbon. Canada is developing a National Forest Carbon Monitoring, Accounting and Reporting System in support of its international obligations to report greenhouse gas sources and sinks. This system employs forest-inventory data, growth and yield information, and statistics on natural disturbances, management actions and land-use change to estimate forest carbon stocks, changes in carbon stocks, and emissions of non-CO₂ greenhouse gases. A key component of the system is the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS). The model is undergoing extensive revisions to enable analyses at four spatial scales (national, provincial, forest management unit and stand) and in annual time steps. The model and the supporting databases can be used to assess carbon-stock changes between 1990 and the present, and to predict future carbon-stock changes based on scenarios of future disturbance rates and management actions.     

Accounting of forest carbon sinks and sources under a future climate protocol—factoring out past disturbance and management effects on age–class structure

Today, forests in the northern hemisphere are a sink for carbon dioxide (CO₂) from the atmosphere, partly due to changes in forest management practice and intensity. Parties of the Kyoto Protocol had the option to elect to account for direct human-induced carbon (C) sources and sinks from land management activities since 1990. The effect of age–class structure of a forest landscape resulting from past practices and disturbances before the reference year 1990 should be excluded, but methods for “factoring out” the effects of this age–class legacy on carbon emissions and removals are lacking. The legacy effect can be strong and can even overwhelm effects of post-1990 management. It therefore needs to be “factored out”, i.e., removed from the direct human-induced post-1990 effects. In this study we examine how the contributions to forest biomass carbon stock changes of (1) past (pre-1990) disturbances and harvest and (2) recent (post-1990) changes in forest management can be differentiated in present and future observable carbon dynamics in managed forest ecosystems. We also calculate the consequences of different accounting rules for the magnitude and direction of accountable C stock changes in European countries in the period 2013–2017.Different accounting approaches are compared in terms of applicability and their ability to provide incentives for management changes to increase carbon sinks and reduce carbon sources. We demonstrate implications of the various ways of accounting for a sample of European countries with different initial age–class structures. The current forest age–class distribution in countries determines whether and how many credits can be created by the various accounting approaches. We suggest an approach that includes a dynamic, forward-looking baseline as reference and list options to define such a baseline. Accounting of recent management change against such a baseline factors out the contribution of the legacy effect to accounting results and only rewards the effect of recent changes in forest management practices in support of climate change mitigation. We demonstrate that relatively simple, state-of-the-art forest models can factor out effects of past practices and past disturbances on present and future carbon stock changes. Factoring out of past practice effects is thus technically feasible but the numerical results are highly dependent on the choice of baseline which will be subject to negotiation. It is possible, however, to select a dynamic baseline that represents “business-as-usual”, and to isolate and account for only the changes in management. Changes in accounting rules will always be advantageous for some countries and disadvantageous for others, but using a dynamic “business-as-usual” baseline effectively removes the legacy of pre-1990 age–class effects, and thus overcomes one of the acknowledged shortcomings of the current accounting approach.     

Trees as carbon sinks and sources in the European Union

The carbon (C) sinks and sources of trees that may be accounted for under Article 3.3 of the Kyoto Protocol during the first commitment period from 2008 to 2012 were estimated for the countries of the European Union (EU) based on existing forest inventory data. Two sets of definitions for the accounted activities, afforestation, reforestation and deforestation, were applied. Applying the definitions by the Food and Agricultural Organization of the United Nations (FAO), the trees were estimated to be a C source in eight and a C sink in seven countries, and in the whole EU a C source of 5.4 Tg year⁻¹. Applying the definitions by the Intergovernmental Panel of Climate Change (IPCC), the trees were estimated to be a C source in three and a C sink in 12 countries, and in the whole EU a C sink of 0.1 Tg year⁻¹. These estimates are small compared with the C sink of trees in all EU forests, 63 Tg year⁻¹, the anthropogenic CO₂ emissions of the EU, 880 Tg C year⁻¹, and the reduction target of the CO₂ emissions, 8%. In individual countries, the estimated C sink of the trees accounted for under Article 3.3 was at largest 8% and the C source 12% compared with the CO₂ emissions.     

A generalised approach of accounting for biospheric carbon stock changes under the Kyoto Protocol

The Kyoto Protocol aims to reduce net emissions of greenhouse gases to the atmosphere by various measures including through management of the biosphere. However, the wording that has been adopted may be difficult and costly to implement, and may ultimately make it impossible to cost-effectively include biosphere management to reduce net greenhouse gas emissions. An alternative scheme is proposed here, especially for the second and subsequent commitment periods, to more effectively deal with the anthropogenic component of carbon stock changes in the biosphere. It would categorise the terrestrial biosphere into different land-use types, with each one having a characteristic average carbon density determined by land-use and environmental factors. Each transition from one land-use type to another, or a change in average carbon density within a specified type due to changed management would be defined as anthropogenic and credited or debited to the responsible nation. To calculate annual credits and/or debits, the change in average carbon stocks must be divided by a time constant which would either be a characteristic of each possible land-use conversion, or applicable to the sum of changes to a nation's biospheric carbon stocks. We believe that this scheme would be simpler and less expensive to implement than one based on the measurement of actual carbon changes from all specified areas of land. It would also avoid undue credits or debits, because they would only accrue as a result of identified anthropogenic components of biospheric carbon changes whereas carbon fluxes that are due to natural variation would not be credited or debited.     

The elephant in the room – A comparative study of uncertainties in carbon offsets

The clean development mechanism (CDM) is a flexible mechanism under the Kyoto Protocol, which makes it possible for developed countries to offset their emissions of greenhouse gases through investing in climate change mitigation projects in developing countries. When the mitigation benefit of a CDM project is quantified, measurable uncertainties arise that can be minimised using established statistical methods. In addition, some unmeasurable uncertainties arise, such as the rebound effect of demand-side energy efficiency projects. Many project types related to land use, land-use change and forestry (LULUCF) have been excluded from the CDM in part because of the high degree of statistical uncertainty in measurements of the carbon sink and risk of non-permanence. However, recent discussions within the United Nations Framework Convention on Climate Change (UNFCCC) have opened up for the possibility of including more LULUCF activities in the future. In the light of this discussion, we highlight different aspects of uncertainties in LULUCF projects (e.g. the risk of non-permanence and the size of the carbon sink) in relation to other CDM project categories such as renewables and demand-side energy efficiency. We quantify the uncertainties, compare the magnitudes of the uncertainties in different project categories and conclude that uncertainties could be just as significant in CDM project categories such as renewables as in LULUCF projects. The CDM is a useful way of including and engaging developing countries in climate change mitigation and could be a good source of financial support for LULUCF mitigation activities. Given their enormous mitigation potential, we argue that additional LULUCF activities should be included in the CDM and other future climate policy instruments. Furthermore, we note that Nationally Appropriate Mitigation Actions (NAMAs) are currently being submitted to the UNFCCC by developing countries. Unfortunately, the under-representation of LULUCF in comparison to its potential is evident in the NAMAs submitted so far, just as it has been in the CDM. Capacity building under the CDM may influence NAMAs and there is a risk of transferring the view on uncertainties to NAMAs.     

Forest carbon accounting methods and the consequences of forest bioenergy for national greenhouse gas emissions inventories

While bioenergy plays a key role in strategies for increasing renewable energy deployment, studies assessing greenhouse gas (GHG) emissions from forest bioenergy systems have identified a potential trade-off of the system with forest carbon stocks. Of particular importance to national GHG inventories is how trade-offs between forest carbon stocks and bioenergy production are accounted for within the Agriculture, Forestry and Other Land Use (AFOLU) sector under current and future international climate change mitigation agreements. Through a case study of electricity produced using wood pellets from harvested forest stands in Ontario, Canada, this study assesses the implications of forest carbon accounting approaches on net emissions attributable to pellets produced for domestic use or export. Particular emphasis is placed on the forest management reference level (FMRL) method, as it will be employed by most Annex I nations in the next Kyoto Protocol Commitment Period. While bioenergy production is found to reduce forest carbon sequestration, under the FMRL approach this trade-off may not be accounted for and thus not incur an accountable AFOLU-related emission, provided that total forest harvest remains at or below that defined under the FMRL baseline. In contrast, accounting for forest carbon trade-offs associated with harvest for bioenergy results in an increase in net GHG emissions (AFOLU and life cycle emissions) lasting 37 or 90 years (if displacing coal or natural gas combined cycle generation, respectively). AFOLU emissions calculated using the Gross-Net approach are dominated by legacy effects of past management and natural disturbance, indicating near-term net forest carbon increase but longer-term reduction in forest carbon stocks. Export of wood pellets to EU markets does not greatly affect the total life cycle GHG emissions of wood pellets. However, pellet exporting countries risk creating a considerable GHG emissions burden, as they are responsible for AFOLU and bioenergy production emissions but do not receive credit for pellets displacing fossil fuel-related GHG emissions. Countries producing bioenergy from forest biomass, whether for domestic use or for export, should carefully consider potential implications of alternate forest carbon accounting methods to ensure that potential bioenergy pathways can contribute to GHG emissions reduction targets.     

What contribution can tree plantations make towards meeting Australia’s commitments under the Kyoto Protocol?

The Kyoto Protocol has been drafted to bring about an overall reduction in net emissions of greenhouse gases to the atmosphere. Australia has agreed to limit its increase of net greenhouse gas emissions to 8% between 1990 and 2010. While this target is not as tight as that of other parties to the Protocol, it nonetheless constitutes a significant reduction of net emissions below business-as-usual projections, and it will require significant policy initiatives to achieve this reduction. The Kyoto Protocol allows some carbon sequestration by vegetation sinks to be offset against CO₂ emissions from the burning of fossil fuels. This paper aims to estimate the contribution that forestation projects could make towards meeting Australia’s commitments under the Kyoto Protocol. It concludes that new plantations could sequester between 0.6 and 7 MtC yr⁻¹ over the commitment period (2008–2012) and offset between about 0.5 and 6% of Australia’s 1990 greenhouse gas emissions. The different estimates depend on the area of eligible plantations that will be established from 1999 onwards and whether plantations will be allowed to grow through to the end of the commitment period or will be in short-rotation stands that may be harvested before 2012. The maximum emission offset can only be achieved if new plantations are established at a rate of 100,000 ha yr⁻¹, which is equivalent to the Australian Government’s target under the 2020 vision. It is likely that sufficient suitable land would be available in Australia to achieve the required establishment rates. However, while such a contribution by vegetation sinks would be helpful, it would not, on its own, be sufficient for Australia to meet its required greenhouse gas emission target.     

Carbon emissions from land-use change: an analysis of causal factors in Chiapas, Mexico

This study examines the correlation between deforestation, carbon dioxide emissions and potential causal factors of land-use change within an area of 2.7 million ha in Chiapas, southern Mexico between 1975 and 1996. Digitized land-use maps and interpreted satellite images were used to quantify land-use changes. Geo-referenced databases of population and digitized maps of roads and topography were used to determine which factors could be used to explain observed changes in land-use. The study analyzed the relationship between carbon emissions during this period and two types of possible causal factors: “predisposing” factors that determine the susceptibility of a particular area of forest to change (slope, distance to agriculture and roads, land tenure) and “driving” factors representing the pressures for change (population density, poverty). The correlated factors were combined in risk matrices, which show the proportion of vulnerable carbon stocks lost in areas with defined social, economic and environmental characteristics. Such matrices could be used to predict future deforestation rates and provide a verifiable evidence-base for defining baseline carbon emissions for forest conservation projects. Based on the results of the analysis, two matrices were constructed, using population density as the single most important driving factor and distance from roads and distance from agriculture as the two alternatives for the predisposing factors of deforestation.     

Wood products: potential carbon sequestration and impact on net carbon emissions of industrialized countries

Carbon stocks in the wood products pool are considered to be increasing globally. Simplified methods for estimating the fate of carbon in wood products need to be prepared to allow estimation at the national level. Since current methods cause some problems when dealing with specific countries, we try to improve the current methods. We discuss the potential carbon sequestration in wood products and the impacts of three accounting approaches (IPCC default, stock-change and atmospheric-flow) on net carbon emissions of 16 industrialized countries. We draw the following conclusions: (1) we improved the current methods for estimating the fate of carbon by considering the recycling of paper and the use of other fiber pulp, but further improvement need to be made; (2) the annual carbon sequestrations in wood products during 1990–1999 correspond to a few to 10% of 1990 base-year emissions from fossil fuels and cement production, depending on country and year. For the analyzed countries as a whole, the annual carbon sequestration was around 2%; (3) the impact of the accounting approaches on net carbon emissions at the national level is significant. Therefore, policy implications must be carefully considered when one of these approaches is adopted.     

Baselines for land-use change in the tropics: application to avoided deforestation projects

Although forest conservation activities, particularly in the tropics, offer significant potential for mitigating carbon (C) emissions, these types of activities have faced obstacles in the policy arena caused by the difficulty in determining key elements of the project cycle, particularly the baseline. A baseline for forest conservation has two main components: the projected land-use change and the corresponding carbon stocks in applicable pools in vegetation and soil, with land-use change being the most difficult to address analytically. In this paper we focus on developing and comparing three models, ranging from relatively simple extrapolations of past trends in land use based on simple drivers such as population growth to more complex extrapolations of past trends using spatially explicit models of land-use change driven by biophysical and socioeconomic factors. The three models used for making baseline projections of tropical deforestation at the regional scale are: the Forest Area Change (FAC) model, the Land Use and Carbon Sequestration (LUCS) model, and the Geographical Modeling (GEOMOD) model. The models were used to project deforestation in six tropical regions that featured different ecological and socioeconomic conditions, population dynamics, and uses of the land: (1) northern Belize; (2) Santa Cruz State, Bolivia; (3) Paraná State, Brazil; (4) Campeche, Mexico; (5) Chiapas, Mexico; and (6) Michoacán, Mexico. A comparison of all model outputs across all six regions shows that each model produced quite different deforestation baselines. In general, the simplest FAC model, applied at the national administrative-unit scale, projected the highest amount of forest loss (four out of six regions) and the LUCS model the least amount of loss (four out of five regions). Based on simulations of GEOMOD, we found that readily observable physical and biological factors as well as distance to areas of past disturbance were each about twice as important as either sociological/demographic or economic/infrastructure factors (less observable) in explaining empirical land-use patterns. We propose from the lessons learned, a methodology comprised of three main steps and six tasks can be used to begin developing credible baselines. We also propose that the baselines be projected over a 10-year period because, although projections beyond 10 years are feasible, they are likely to be unrealistic for policy purposes. In the first step, an historic land-use change and deforestation estimate is made by determining the analytic domain (size of the region relative to the size of proposed project), obtaining historic data, analyzing candidate baseline drivers, and identifying three to four major drivers. In the second step, a baseline of where deforestation is likely to occur–a potential land-use change (PLUC) map—is produced using a spatial model such as GEOMOD that uses the key drivers from step one. Then rates of deforestation are projected over a 10-year baseline period based on one of the three models. Using the PLUC maps, projected rates of deforestation, and carbon stock estimates, baseline projections are developed that can be used for project GHG accounting and crediting purposes: The final step proposes that, at agreed interval (e.g., about 10 years), the baseline assumptions about baseline drivers be re-assessed. This step reviews the viability of the 10-year baseline in light of changes in one or more key baseline drivers (e.g., new roads, new communities, new protected area, etc.). The potential land-use change map and estimates of rates of deforestation could be re-done at the agreed interval, allowing the deforestation rates and changes in spatial drivers to be incorporated into a defense of the existing baseline, or the derivation of a new baseline projection.     

The Monitoring,Evaluation, Reporting and Verification of Climate Change Projects

Because of concerns with the growing threat of global climate change from increasing emissions of greenhouse gases, the United States and other countries are implementing, by themselves or in cooperation with one or more other nations, climate change projects. These projects will reduce greenhouse gas (GHG) emissions or sequester carbon, and will also result in non-GHG benefits (i.e., environmental, economic, and social benefits). Monitoring, evaluating, reporting, and verifying (MERV) guidelines are needed for these projects to accurately determine their net GHG, and other, benefits. Implementation of MERV guidelines is also intended to: (1) increase the reliability of data for estimating GHG benefits; (2) provide real-time data so that mid-course corrections can be made; (3) introduce consistency and transparency across project types and reporters; and (4) enhance the credibility of the projects with stakeholders. In this paper, we review the issues involved in MERV activities. We identify several topics that future protocols and guidelines need to address, such as: (1) establishing a credible baseline; (2) accounting for impacts outside project boundaries through leakage; (3) net GHG reductions and other benefits; (4) precision of measurement; (5) MERV frequency and the persistence (sustainability) of savings, emissions reduction, and carbon sequestration; (6) reporting by multiple project participants; (7) verification of GHG reduction credits; (8) uncertainty and risk; (9) institutional capacity in conducting MERV; and (10) the cost of MERV.     

一种部分碳税机制的经济分析

基于目前全球气候变化谈判的困境提出一种部分碳税机制,这种机制与1997年12月缔约国大会第三次会议所形成的京都议定书第12条确立的清洁发展机制（CDM）的雏形清洁发展基金（CDF）有相似的特征,即要求附件Ｉ缔约方为实现公约的目的和体现公约有区别的责任原则,通过实行统一的税收机制并将税收收入转移到发展中国家作为他们在历史过程中过多排放温室气体的自然债务的补偿     

Global Carbon Dioxide Emissions Scenarios: Sensitivity to Social and Technological Factors in Three Regions

Carbon dioxide emissions from 1990 to 2100 AD are decomposed into the product of four factors: population size, affluence (measured here as GDP per capita), energy intensity (energy use per unit GDP) and carbon intensity (carbon dioxide emissions per unit energy). These emissions factors are further subdivided into three regions: more developed countries (MDCs), China, and the remaining less developed countries (LDCs). Departures from a baseline scenario (based on IPCC, 1992a — the so-called ‘business-as-usual’ scenario) are calculated for a variety of alternative assumptions concerning the four emissions factors in the three regions. Although the IPCC scenario is called a ‘non-intervention’ scenario, it is shown, for example, that large decreases in energy intensity in China or carbon intensity in MDCs are built into the ‘business as usual’ case — and such large changes vary considerably from region to region. We show what CO₂ emissions would look like if each of these four emissions factors projected in the baseline case somehow remained constant at 1990 levels. Certain factors like energy intensity improvements and long-term population growth in LDCs, or GDP growth and carbon intensity improvements in MDCs, are shown to have a big contribution to cumulative global emissions to 2100 AD, and consequently, changes in these projected factors will lead to significant deviations from baseline emissions. None of the scenarios examined in this analysis seems to indicate that any one global factor is clearly dominant, but cultural, economic, and political costs or opportunities of altering each factor may differ greatly from country to country.     

Global Carbon Dioxide Emissions Scenarios: Sensitivity to Social and Technological Factors in Three Regions

Carbon dioxide emissions from 1990 to 2100 AD are decomposed into the product of four factors: population size, affluence (measured here as GDP per capita), energy intensity (energy use per unit GDP) and carbon intensity (carbon dioxide emissions per unit energy). These emissions factors are further subdivided into three regions: more developed countries (MDCs), China, and the remaining less developed countries (LDCs). Departures from a baseline scenario (based on IPCC, 1992a — the so-called ‘business-as-usual’ scenario) are calculated for a variety of alternative assumptions concerning the four emissions factors in the three regions. Although the IPCC scenario is called a ‘non-intervention’ scenario, it is shown, for example, that large decreases in energy intensity in China or carbon intensity in MDCs are built into the ‘business as usual’ case — and such large changes vary considerably from region to region. We show what CO₂ emissions would look like if each of these four emissions factors projected in the baseline case somehow remained constant at 1990 levels. Certain factors like energy intensity improvements and long-term population growth in LDCs, or GDP growth and carbon intensity improvements in MDCs, are shown to have a big contribution to cumulative global emissions to 2100 AD, and consequently, changes in these projected factors will lead to significant deviations from baseline emissions. None of the scenarios examined in this analysis seems to indicate that any one global factor is clearly dominant, but cultural, economic, and political costs or opportunities of altering each factor may differ greatly from country to country.