Chapter 2 of this Special Report describes the components of the global carbon cycles and the issues to be considered in accounting for carbon fluxes to and from the atmosphere.
The IPCC Guidelines (IPCC, 1997) describe a methodology for a comprehensive approach to measuring "anthropogenic emissions by sources and removals by sinks of greenhouse gases" that is feasible to implement in most nations. These guidelines include suggested definitions for many important terms and can form a starting point for reporting compliance with the Kyoto Protocol. Article 5.2 and a decision at COP3 (2/CP.3) states that the "[m]ethodologies for estimating anthropogenic emissions by sources and removals by sinks of all greenhouse gases not controlled by the Montreal Protocol shall be those" in the IPCC Guidelines. A variety of ill-defined terms and ambiguities may cause problems, however, in putting the Protocol into operation. There are also other sets of definitions in use nationally and internationally, such as those suggested by the UN Food and Agriculture Organization (FAO) for forestry applications and land use (FAO, 1999). Article 5.2 states that where the IPCC Guidelines are not used, "appropriate adjustments shall be applied according to methodologies agreed upon by the" first COP.
This chapter outlines the generic issues associated with specific definitions and methodologies that Parties might wish to consider in agreeing on methodologies in accordance with Articles 5.2 and 7.4. The broad picture in this chapter is elaborated in subsequent chapters.
A central issue in identifying lands that may fall under Articles 3.3 and 3.4 is the definition of ARD, which in turn is related to the definition of a forest. Section 2.2 deals with this issue, and Chapter 3 elaborates on it, analyzing the implication of a series of definitional scenarios. Some activities that take place in forested land but do not fall within Article 3.3 may be eligible for inclusion under Article 3.4. These options are further discussed in Chapter 4.
Afforestation, reforestation, and deforestation are usually defined as activities that change a piece of land between a forested and non-forested state. The IPCC Guidelines do not provide an explicit definition of a forest. They refer to the FAO (1993a) usage for the tropics as example categories, but they note that "[n]ational experts are free, indeed encouraged, to use more detailed characterizations of ecosystems in their countries." In this section, we first discuss definitions of a forest because the precise definition used can have a significant effect on actions that are classified as ARD and thus on measured emissions and sinks of GHGs.
We then discuss alternative definitions of ARD and their relationship with land use and land-use change. The precise definitions affect which lands are lands under Article 3.3 activities and which may be considered under Article 3.4. The quantitative implications of different definitional scenarios are described in detail in Chapter 3; options for additional activities under Article 3.4 are described in Chapter 4.
Alternative definitions abound for some of the fundamental concepts relevant to the land-use change and forestry (LUCF) sector. For example, a recent survey (Lund, 1999) listed more than 200 definitions of "forest," 50 definitions of "a tree," and another 50 definitions of "reforestation." This Special Report discusses alternative definitions and their merits, demerits, and implications in a way that is not policy prescriptive. Considering all of the alternative definitions and their interactions is impossible, however, because the number of combinations quickly increases beyond practical limits. In selecting definitions for discussion, we have considered their utility in estimating carbon stocks and changes in stock in a manner that is relevant to the Kyoto Protocol.
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