Kyoto Protocol greenhouse gases and the Canadian Environmental Protection Act: chapter 1

1.1 Purpose of the Report

The purpose of this Report is to determine whether the greenhouse gases (GHGs) addressed by the Kyoto Protocol (and not others) (namely, carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs)) meet one or more of the criteria set out in section 64 of the Canadian Environmental Protection Act (CEPA, 1999). This Report examines the relevance of the scientific information presented in the Third Assessment Report of the Intergovernmental Panel on Climate Change (IPCC TAR) to the criteria set out in Section 64 of CEPA.

1.2 Scope of the Report

This Report is divided in four sections. This first section (the Introduction) sets the stage for consideration of the relevant science in the sections that follow. The purpose and scope of the report are described, and the rationale for relying on science from the IPCC Third Assessment Report is provided. The second section (IPCC conclusions on current and future climate change) presents the main conclusions from the IPCC TAR on the issues of observed climate change and its causes and future climate change. In that section, evidence is presented on the role of human emissions of GHGs in climate change, a conclusion which then justifies a subsequent discussion of whether or not GHGs meet the criteria set out in Section 64 of CEPA 1999.

The third section (Assessment of GHGs within the context of CEPA 1999 Section 64) presents particular lines of evidence from the IPCC TAR that are considered to be most relevant to CEPA 1999 Section 64. The final section provides a conclusion on whether the information, as documented in the IPCC TAR and summarized in this report, would support a recommendation by the Ministers to Governor in Council to add GHGs to Schedule 1 of CEPA 1999 pursuant to the criteria set out in Section 64.

1.3 The IPCC Third Assessment Report (TAR)

As stated above, the approach used in this report is to consider the lines of evidence on the consequences of climate change, as assessed by the IPCC TAR, within the context of Section 64 of CEPA 1999. The IPCC TAR included four reports: Climate Change 2001: The Scientific Basis (Contribution of Working Group l), Climate Change 2001: Impacts, Adaptation and Vulnerability (Contribution of Working Group ll), Climate Change 2001: Mitigation (Contribution of Working Group lll), Climate Change 2001: Synthesis Report. All of these except the report on mitigation are relevant to the issue at hand. It is not the objective of this report to provide a comprehensive summary of IPCC findings on the science and impacts of climate change. Rather, the intent of this report is to provide sufficient coverage to enable a decision regarding whether or not there is evidence that GHGs meet any of the criteria under Section 64 of CEPA 1999.

The IPCC was established by UN agencies in 1988 to undertake periodic comprehensive assessments of the available scientific and socio-economic information on climate change and its impacts and on options for mitigating and adapting to the risks posed by climate change. To date, the IPCC has issued comprehensive assessments in 1990, 1996 and 2001. Preparation of a fourth assessment report is underway. The IPCC is often called on to advise the Conference of the Parties, and other bodies to the UN Framework Convention on Climate Change.

Preparation of IPCC assessment reports is undertaken with the help of several thousand experts from around the world. Canadian experts have been substantively involved in each of the three assessments produced to date and are similarly making significant contributions to the preparation of the fourth assessment report. The individual IPCC WG reports are based on an assessment of published, peer-reviewed technical literature available at the time of preparation of the report. The TAR, published in 2001, was therefore based on available science up to and including 2001. (Papers that were accepted for publication but not yet in print were included in the literature base for the TAR.)

The IPCC assessment reports themselves undergo a very extensive and open peer review process involving hundreds of government and non-government experts. The completed assessment reports are finalized and then accepted at Sessions of the respective Working Groups. Plenary Sessions of the IPCC, attended by representatives of some 120 Nations, then accept the decisions of the Working Groups regarding their final reports and approve the Summaries for Policymakers that accompany each technical report. The contributions of the three Working Groups to the TAR were accepted, and the Summaries for Policymakers approved, at the 17th Session of the IPCC. The 18th Session of the IPCC adopted the Synthesis Report and approved its Summary for Policymakers.

The value of the IPCC Assessments is in their assessment of a vast and complex technical literature than reaches across many scientific and social disciplines. It is also in the process of consensus building that occurs during the preparation of IPCC reports. This is a fundamental component of any scientific assessment process; to establish, based on existing knowledge, what can be agreed upon, how confident scientists are in these conclusions, and what areas of uncertainty remain. The consensus that forms does not mean that there is unanimity of opinion among scientific experts but rather that the weight of evidence from the scientific literature, at that point in time, supports the conclusions drawn.. Individual papers and individual scientists may disagree with the conclusions but the conclusions are consistent with and a fair representation of the larger body of literature that exists. The level of agreement among scientists is in any case reflected in the confidence and likelihood statements that are attached to particular results (and the IPCC has a well established lexicon for articulating such things (see Section 2.3 of this report)).

As a result of the processes used to prepare IPCC reports, the IPCC is widely recognized as the international authority on climate change science. Following release of the TAR, 17 National Academies of Science1, from many countries of the world, endorsed its conclusions and the process used to prepare its reports. In addition, a special committee of the US National Research Council advised the American President George Bush that the full IPCC Working Group I report of the Third Assessment (dealing with climate system science and predictions) was an "admirable summary of research activities in climate change"2. These reports have thus been accepted internationally as authoritative statements of the current state of scientific knowledge on climate change.

For these reasons, additional science reviews have not been undertaken by Environment Canada and Health Canada for the purpose of considering whether GHGs meet the criteria set out in section 64 of CEPA 1999. The Departments have used material from the IPCC TAR exclusively. The findings of the TAR are recent and have already been accepted by scientists and governments worldwide. Furthermore, the scientific literature published since 2001, which will be included in the Fourth Assessment Report of the IPCC (to be produced in 2007), is expected to strengthen the conclusions of the TAR.

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