IPCC Fourth Assessment Report: Climate Change 2007
Climate Change 2007: Working Group III: Mitigation of Climate Change

12.2.4 Opportunities at the sectoral level to change development pathways towards lower emissions through development policies

The multiplicity of plausible development paths ahead are underlined in Section 12.2.1, in which low emissions are not necessarily associated with low economic growth (Section 12.2.2). However, the vast literature on governance indicates that changing development pathways can rarely be imposed from the top: it requires the coordination of multiple actors, at multiple scales (Section 12.2.3).

On this basis, examples of opportunities to change development pathways towards lower emissions at the sectoral level are presented in Section 12.2.4. Firstly, opportunities in major sectors are reviewed: energy (Section 12.2.4.1); transportation and urban planning (Section 12.2.4.2); rural development (Section 12.2.4.3); and macro-economy and trade (Section 12.2.4.4). Some general lessons are drawn in Section 12.2.4.5. The potential for action on non-climate policies in major sectors is summarized in Section 12.2.4.4, and some insights on how climate considerations could be mainstreamed into non-climate policies in Section 12.2.4.7.

In reviewing how individual policies not intended for climate mitigation impact GHG emissions, examples are drawn from policies already adopted and implemented, and from forward-looking analysis to estimate the impact of future non-climate policies on emissions. However, few case studies directly analyze the link between a given policy and GHG emissions, and these are mostly in the energy sector.

In fact, assessing the impact of specific policies on GHG emissions, even ex post, is difficult for at least four reasons. First, policy packages usually encompass a wide range of measures, making it difficult to disentangle their individual effects. Second, absent command-and-control policies, or cases in which the emission-producing sectors are directly controlled by governments, public policies are only one of many incentives that decision-makers react to (see also Section 12.2.3). Third, indirect effects of policies on emissions, such as increased demand induced by energy efficiency programmes, are even more difficult to evaluate. And last, there is rarely a control group on the basis of which carbon savings can be evaluated.

To make up for the scarce literature on the relationships between policies and emissions, studies of the relationships between policies and proxies and/or key determinants of GHG emissions are also included in the review, for example, studies linking land-use policies with deforestation rate. This allows examples to be drawn from a wider range of sectors, namely energy, transportation and construction, rural development, as well as from macro-economic and trade policies. The depth of the literature, however, is variable across sectors. Finally, the examples below are intended to discuss the relationships between given policies and GHG emissions, and not the pros and cons of each policy.