Forest carbon accounting: overview and principles.

Abstract

2 Forest Carbon Accounting: Overview & Principles Executive Summary Forests play an important role in the global carbon balance. As both carbon sources and sinks, they have the potential to form an important component in efforts to combat global climate change. Accounting for the carbon within forest ecosystems and changes in carbon stocks resulting from human activities is a necessary first step towards the better representation of forests in climate change policy at regional, national and global scales. The United Nations Development Programme (UNDP), as part of the UNDP-UNEP CDM Capacity Development Project for Eastern & Southern Africa, is seeking to promote carbon projects in sub- Saharan Africa, in the important bio-carbon sector and others. This report reinforces UNDPs capacity building efforts by presenting the main principles, practices and challenges of carbon accounting in the forestry sector. Forest carbon accounting can be divided into three forms. Stock accounting assesses the magnitude of carbon stored in forest ecosystems at a single point in time. Emissions accounting assesses the net greenhouse gas emissions to the atmosphere resulting from forests. Emission reductions accounting assesses the decrease in emissions from project or policy activities, often so that they can be traded. Forest carbon accounting identifies the carbon-density of areas, providing information for low- carbon-impact land use planning. It prepares territories for accounting and reporting of emissions from the forestry sector. It allows comparison of the climate change impact of the forestry sector relative to other sectors, as well as allowing comparison between territories. Finally, it enables trade of project emission reductions on carbon markets and for emission reductions to be included in policy targets. Good practice in forest carbon accounting must be adhered to. In particular, transparency in methods and accuracy and precision in accounting are required for public and political acceptance of resultant estimates. A basic knowledge of the principles underlying forest carbon accounting is also beneficial. Understanding biomass dynamics and flows between carbon pools in forest ecosystems enables more effective accounting. The practice of forest carbon accounting requires clear identification of the accounting boundary in both space and time. Stratifying the forest into areas with similar carbon characteristics further improves the accuracy of carbon accounting. Data for accounting can be gathered from a variety of sources, including existing secondary data, remotely sensed data and primary data through field surveys. The amount of data from each source depends on the quality of the source as well as the trade-offs that must be made between accounting accuracy and costs of resources and time. All forest carbon accounting estimates contain uncertainty. Practitioners should identify, minimise where possible, and quantify this uncertainty through statistical analysis, published information and expert judgement. Uncertainty of model variables and components, once quantified, can be aggregated through simple propagation of errors or simulated through Monte Carlo analysis. The existence of substantial uncertainty can undermine efforts to reduce carbon emissions from forestry and can erode political support for the accounting process. Forest carbon accounting guidance from the Intergovernmental Panel on Climate Change (IPCC) has become the primary source of information for methods, accounting equations and parameters. However, IPCC guidance is vast and often difficult to navigate. In response, a number of tools for forest carbon accounting have emerged. These vary in terms of geographical coverage, forestry activities and the carbon pools accounted for, as well as the level of data input required. In light of such diversity, practitioners require an understanding of the forest carbon accounting process, irrespective of whether these tools are utilised. Despite substantial progress in the field of forest carbon accounting over the last decade, challenges still remain. Terminology relating to forests and managed lands is ambiguous and requires standardisation between stakeholders. More scientific research into forest biomass characteristics is also required to better incorporate the heterogeneity of forests, their growth dynamics and the fate of carbon in harvested wood products into forest carbon accounting methods. Forest carbon accounting is a multi-disciplinary task. Building capacity is essential. Investment is also necessary to improve and standardise carbon accounting methods. If future climate change policy and strategy are to adequately reflect the substantial role forests play in the global carbon balance, good forest carbon accounting is imperative.