A REVIEW OF EXISTING METHODS FOR CARBON ACCOUNTING AND IMPLICATIONS FOR THE ASSESSMENT OF EMISSIONS FROM BIOENERGY

摘要

The paper first reviews existing methods for carbon accounting for forest-based bioenergy development. We review: 1 the IPCC Good Practice Guidance for LULUCF and the 2006 IPCC Guidelines for National GHG Inventories; and 2 the Directive 2009/28/EC of the European Parliament and of the Council. The IPCC Guidelines adopt a tiered approach for accounting where Tier 1 uses simple default parameters and methodologies. Tier 2 uses, in general, the same methodologies with national or regional data. Tier 3 is full carbon accounting that uses complicated carbon flow models parameterized with regionally specific information. Finally, the EU – Renewable Energy Directive adopts its own methodology (in particular linearization of the carbon stock changes over 20 years) but it is based on the IPCC Guidelines. We then use examples to illustrate the benefits and shortcomings of the reviewed methodologies. The examples have been chosen to highlight specific changes in land management that occur in bioenergy development. They include: 1. Reforestation: conversion of grasslands to short rotation forests; and 2. Forest management: use of harvest residuals. These examples highlight the necessity of: 1. using Tier 2 or Tier 3 methods for forestry; 2. including dead wood and litter; and 3. using a linearization period over the first rotation, if a linear approximation is adopted.