Appendices

• Appendix 1: Workshop Schedule and Partcipants
• Appendix 2: Findings from the Environmental Assessment (EA) Review by Lalani (2003)
• Appendix 3: Recommendations for Guidelines from Lalani (2003)
• Appendix 4: Recommended Guidelines from Yeomans (2004)

Appendix 1: Workshop Schedule and Participants

Workshop on Addressing Climate Change and Its Uncertainties in Environmental Assessments - Monday, June 9, 2003

Workshop Participants

Catherine Badke
Senior EA Officer, Office of Environmental Affairs
Natural Resources Canada

Lesley Baker
Senior Environmental Officer
Public Works Government Services Canada

Hugh Benevides
Environmental Law and Policy Research

Margo Burgess
EA Review Coordinator, Geological Survey of Canada, Earth Sciences Sector
Natural Resources Canada

Dave Broadhurst
Meteorologist, Atmospheric Science Division
Environment Canada

Abel Centella,
Scientific Director, Meteorological Services
Coordinator, National Group on Climate Change
Cuba

Michael Charles
Dean Emeritus and Professor, Department of Chemical Engineering and Applied Chemistry
University of Toronto

Quentin Chiotti
Air Programme Director and Senior Scientist
Pollution Probe

Bas Cleary
Director, Environmental Assessment Division
Newfoundland Department of Environment

Shirley A.M Conover
President, ABER Ecological Consulting LTD

Rob Dobos
Head, Assessment, Canada Centre for Inland Waters
Environment Canada

Lee Doran
Ecological Writings # 1, Inc.

Paul A. Gray
Coordinator, Climate Change Program, Applied Research and Development Branch
Ontario Ministry of Natural Resources

Betty E. Hansen
President, Ecosystems International Environmental Consulting

Danny Harvey
Professor, Department of Geography
University of Toronto

Olga Ijewliw
EA Review Coordinator, Geological Survey of Canada, Earth Sciences Sector
Natural Resources Canada

Oscar Koren
Canadian Meteorological and Oceanographic Society
Environmental Coordinator, Slovenian Sports Federation-Environmental Group

Juan Llanes
Professor, Department of Economic Development
University of Havana, Cuba

Uwe Mader
Environmental Services
City of Toronto

Syed Moin
Hydrologic Systems Engineer
Environment Canada

Brett Maracle
Senior Program Officer
Canadian Environmental Assessment Agency

Don MacIver
Adaptation and Impacts Research Group
Environment Canada

Linda Mortsch
Adaptation and Impacts Research Group, Meteorological Service of Canada
Environment Canada

Melanie Murphy
Toronto Public Health
City of Toronto

Derryk Renton
Environmental Assessment Co-ordinator
Ontario Ministry of Natural Resources

Paul Savoie
Impact Assessment Biologist, Great Lakes Area / Central & Arctic Region
Fisheries and Oceans Canada

Al Scobie Vachon
Federal-provincial-territorial working group on climate change and environmental assessment.
Canadian Environmental Assessment Agency

Julio Torres Martínez
CITMA Ministerio De Ciencia Technologia y Medio, Cuba

May Lyn Trudelle
Program Support Coordinator, Environmental Assessment and Approvals Branch
Ontario Ministry of the Environment

Mark Winfield
Director, Environmental Governance
Pembina Institute for Appropriate Development

Appendix 2: Findings from the Environmental Assessment (EA) Review by Lalani (2003)

From: Lalani, M.J. A Review of the Consideration of Climate Change in Recent Environmental Assessments and Recommendations for Guidelines. M.A. Paper, Toronto: Department of Geography, University of Toronto, 2003, Chapter 3.

Findings from the Environmental Assessment (EA) Review

The EAs selected for this review all contained potentially significant climate change issues. The following findings characterize the 11 reviewed EAs according to: whether they considered how the project may impact GHG emissions; whether they considered whether climate change may impact the project; whether climate change was considered in impact predictions and; whether climate change uncertainties were considered.

General Findings

• Six of the 11 EAs (St. Mary's Dock Expansion, Little Jackfish Hydroelectric Project, Mattagami River Hydroelectric Extensions, Little Bow Diversion Project, Aquarius Gold Mine and Pickering A Return to Service) did not address any aspect of climate change.
• Three of the 11 EAs reviewed (Diavik Diamond Mine, White Rose Oil and Gas and the Cascade Heritage Park) contemplated whether the proposed project may produce GHGs. This aspect was based on considering the quantity of GHG emissions predicted to be produced by the project.
• Four of the 11 EAs (Northumberland Strait Crossing, Cascade Heritage Park, Elliot Lake Mine Decommissioning, and Diavik Diamond Mine) evaluated to some extent how climate change could impact the project.
• One of the 11 EAs (Northumberland Strait Crossing) suggested how climate change might affect environmental impact predictions.
• Three of the EAs (Northumberland Strait Crossing, Elliot Lake Mine Decommissioning and Diavik Diamond Mine) addressed, to a certain extent, the implications of future climate change uncertainties on the project.
• Recent EAs (circa 2000) did not always address climate change in a more comprehensive manner than EAs completed at an earlier date [e.g. the Northumberland Strait Crossing EA (1990) deals with climate change more comprehensively than the White Rose Offshore Oil and Gas project (2000)].

Specific Findings

All of the EAs had climate change issues that should have been addressed in varying degrees of detail. Different climate change issues existed for each project, based on its location and use of natural resources.

Specific findings have been separated into the following categories: the potential of the project to produce GHG emissions; the potential impact of climate change on the project; the potential effects of climate change in impact predictions; climate change uncertainties; and other.

Findings Related to the Potential of the Project to Impact Climate Change

EAs were reviewed to identify whether GHG emissions were considered when determining the proposed project's potential effects on the environment. Below is a summary of these findings:

1) Three of the 11 EAs recognized that the project would emit GHGs and two of these EAs analyzed whether the project would reduce GHG emissions by incorporating energy efficiencies into the project or by using non-fossil fuels.

1. One EA (Diavik Diamond Mine) undertook an inventory of GHG emissions for the full life cycle of the project (construction, operation, transportation of goods, decommissioning). White Rose Oil and Gas Development estimated GHG emissions during operation only and Cascade Heritage Park concluded that significant GHG emissions would not be produced by flooding vegetation for a hydroelectric reservoir.
2. One EA (Cascade Heritage Park) indicated that GHG emissions would be offset as a result of the project because hydroelectric energy was displacing fossil fuel use.
3. One EA (Diavik Diamond Mine) incorporated energy efficiencies and recovery into the project in order to reduce the GHG emissions generated from the project.
4. In cases where EAs estimated GHG emissions for the project, the conclusion was that the emissions were insignificant because national GHG emissions were used as a benchmark. These disparate benchmarks (a project's GHG emissions versus a nation's gross emissions) make it difficult to assess the significance of the project's emissions). The context for comparison would be more effectively represented if similar scales for GHG emissions were used (e.g. the same type of project).
5. When addressed, the EAs considered the propensity of the project to produce carbon dioxide and sometimes methane and nitrous oxide. Other GHGs such as hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride were not identified in the reports. It is not clear whether proponents were aware that these compounds are GHGs and should be included in inventories.

Findings Related to the Potential Impact of Climate Change on the Project

EAs were reviewed to determine whether the potential for climate change to impact the project was considered. Below is a summary of these findings:

1) Four of the 11 EAs evaluated to an extent how climate change could impact the project.

1. The Northumberland Strait Crossing EA considered rising sea levels resulting from climate change and the long-term effects this would have on the bridge structure. An analysis of potential flooding of low-lying areas also included a consideration of climate change. Northumberland Strait Crossing also demonstrated evidence of design considerations that prepared the project should climate change impacts occur. The project was designed to accommodate a one-metre rise in sea level and reinforcements were installed at the base of the bridge to protect against increased tidal forces that may result in a changed climate. Otherwise, project designs described in EAs were not adjusted to accommodate changes in climate.
2. The Cascade Heritage Park EA recognized that climate change would likely cause alterations in hydrological conditions.
3. The Elliot Lake Mine Decommissioning acknowledged that precipitation patterns would likely be altered as a result of climate change.
4. The Diavik Diamond Mine EA determined that climate change may cause permafrost, which was used as a structure to stabilize the mine, to melt more quickly than observed in historical data.

Other observations about climate change and the project were made. These findings are:

1. Factors of climate change that could impact the project were typically considered in isolation, and not cumulatively in the EAs. For example, sea level rise predictions were sometimes considered, but not in conjunction with other predictions of climate change such as modified precipitation patterns.
2. Climate change was invariably indicated to be an insignificant issue by the proponent. Little supporting evidence typically accompanied such a statement. Panels and government reviews, however, typically found climate change issues to be quite significant, and worthy of greater analysis.
3. The EAs did not provide a clear methodology for how climate change was addressed, or indicate how the results informed decision-making.
4. The EAs for projects that could be impacted by climate change in very direct and distinct manners (e.g. economic viability) sometimes did the most minimal evaluation of climate change on the project.
5. The EAs did not consider "surprise" events, or extreme events that may occur in a changed climate.
6. The EAs did not integrate multiple benchmark time periods of climate change over the life of the project. For example, the potentially evolving impacts associated with climate change were not determined over 10, 30, 50, and 75 years.
7. The EAs did not consider the effects of climate change and the rate of structural deterioration of the project to ensure that structures are capable of withstanding the effects of climate change over the life of the project.
8. With the exception of two proposed projects, the EAs did not incorporate engineering designs that respond to, or mitigate the effects of climate change on the project.
9. The EAs did not develop mechanisms to monitor the occurrence of climate change predictions unless instructed to do so by a Panel.

Findings Related to the Potential Effects of Climate Change on Impact Predictions

EAs were reviewed to determine whether the potential effects of climate change on impact predictions were considered. Below is a summary of these findings:

1. One EA (Northumberland Strait Crossing) addressed, to an extent, the potential effects of climate change on impact predictions. The EA addressed the potential effects of sea level rise associated with climate change on agriculture and fisheries.

Other observations from the EAs regarding climate change were also made. These findings are:

1. All of the EAs contained VECs that may be sensitive to climate change (e.g. flora and fauna), yet an analysis was not undertaken to this effect.
2. The EAs did not consider the synergistic effects of projects and climate change on impact predictions.
3. The EAs did not integrate less formal forms of knowledge of climate change (e.g. community, or traditional ecological knowledge) into establishing potential impacts of climate change on VECs.

Findings Related to Climate Change Uncertainties

EAs were reviewed to determine whether climate change uncertainties were considered. Below is a summary of these findings:

Three of the EAs (Northumberland Strait Crossing, Elliot Lake Mine Decommissioning and Diavik Diamond Mine) addressed, to a certain extent, the implications of future climate change uncertainties on the project.

1. An Expert Panel considered different worse case scenarios when estimating the extent to which the bridge may affect the ice-out date in a changed climate in the Northumberland Strait Crossing EA. Expert judgment was also used for addressing the uncertainties of potential sea level rise as a result of climate change.
2. The Elliot Lake Mine Decommissioning EA used probability models to assess the uncertainty related to drought and flood events that could result from climate change. Expert opinion was used to factor into the models the uncertainties posed by potential effects of drought and flooding in a changed climate.
3. The Diavik Diamond Mine EA considered uncertainties of climate change by using expert opinion and scenario analysis for examination of GHG emissions from the project and for determining potential outcomes of climate change. Some evidence in the EA suggested a sensitivity analysis may have been used to determine how different factors of climate change may affect permafrost and the project design.

Other observations regarding climate change uncertainties in the EAs were made. These findings include:

1. EAs did not provide evidence for the importance of climate change uncertainties for the project.
2. EAs did not identify climate change uncertainties for each issue of climate change that may affect the project.
3. EAs did not clearly define uncertainty terminology.
4. EAs did not address climate change uncertainties in a consistent manner, even for similar projects.
5. Expert opinion played an instrumental role in addressing uncertainties of climate change.
6. EAs that considered climate change uncertainties related to extreme weather largely focused upon rainfall, sea level, changes in permafrost, drought, and flooding. However, extreme weather events that could have significant implications for infrastructure, such as tornadoes, wind, ice, or hail storms, or events induced by weather, such as forest fires from severe thunderstorms, were not considered.
7. When the EAs examined climate change uncertainties, a comprehensive approach was not used (e.g only limited climate change issues, their implications for the project and the project's environmental impacts were reviewed).
8. The methodology used to address climate change uncertainties in the EAs reviewed was frequently unclear. For example, it was deduced in one EA that sensitivity analysis that incorporated expert opinion may have been used, but this was not stated in the EA.
9. Climate change uncertainty was not considered when assessing cumulative impacts in EAs.
10. Climate change uncertainties were not addressed by the proponent in developing mitigation or post-project monitoring strategies, unless specifically directed to do so by government reviewers or a Panel.
11. The design of projects typically changed when government reviews or Panels directed the proponent to consider elements of climate change uncertainty.
12. Proponents did not consider climate change uncertainties as a criterion in evaluating alternatives to the undertaking, or alternative locations.
13. In cases where climate change uncertainties were addressed in EAs, sensitivity analysis, scenario analysis, and probabilistic analysis were the tools used to address uncertainties of climate change.

Findings Related to Government Agencies and Panel Reviews

Further observations from the EAs were noted that relate to climate change and the involvement of government agencies (including Responsible Authorities) and the three Panel Reviews. These findings include:

1. Government agency comments that were available on the EAs demonstrated that proponents did not receive consistent direction on how to address climate change. As a result, the EAs demonstrated significantly different approaches for addressing climate change.
2. Government agency and Panel reviews recognized climate change as a potentially important issue, whereas EA practitioners tended to address it in a cursory fashion and/or only when directed to do so.
3. Proponents did not seem to be aware of completed studies related to climate change that may pertain to their project prior to the submission of the EA. From the reports reviewed, government agencies are providing this information to the proponent following the submission of the EA report to government agencies.

Appendix 3: Recommendations for Guidelines from Lalani (2003)

From: Lalani, M.J. A Review of the Consideration of Climate Change in Recent Environmental Assessments and Recommendations for Guidelines. M.A. Paper, Toronto: Department of Geography, University of Toronto, 2003, Chapter 4.

Recommendations for Guidelines

Based on the findings from the 11 EAs, it is evident that guidance should be developed to assist proponents in addressing climate change uncertainties in EAs. This direction should be focused on assisting proponents in producing high quality, consistent EAs in an efficient manner, contributing to better communication of climate change uncertainties, and ultimately leading to more effective EAs and better decision-making. Guidelines should work towards improving the rigor of climate change uncertainty analysis, enhancing the relevance of climate change analysis (in terms of informing decision-making) and making the EA process more predictable.

Guidelines for Proponents

Proposed guidelines ³ on climate change in EAs have been separated into the following categories: greenhouse gas emissions; the potential impact of climate change on the project; the potential effects of climate change on impact prediction and; climate change uncertainty. It is recognized that proponents will require further guidance from the Canadian Environmental Assessment Agency on each of these guidelines. The guideline for proponents is provided in italics. Further explanation accompanies each guideline where applicable.

Guidelines Related to Greenhouse Gas (GHG) Emissions

1) Proponents should undertake a preliminary assessment to determine the quantity, if any, of GHGs that will be produced from the project.

2) Proponents should use a life cycle approach to analyzing GHG emissions in EAs.

Life cycle analysis of GHG emissions involves identifying all sources of GHGs throughout each stage of the project including construction, operation, decommissioning, and any perpetual project elements. This type of analysis is dependent on the specific characteristics of each project. A mining project may produce greenhouse gas emissions during construction, operating and distribution phases, while for a highway, the majority of greenhouse gases would be produced during its use. Scenarios for different operating capacities should also be examined to determine the emissions at full and partial functioning of facilities.

3) Proponents should determine the significance of the project's potential contribution to climate change through the production of GHGs.

The review of the 11 EAs demonstrates that two proponents addressed production of GHG emissions. These EAs indicated that the project would not significantly impact climate change by comparing the project's GHG emissions to Canada's emissions as a whole. A more meaningful method may involve comparison at a regional (comparing project emissions with the emissions of a city), or sectoral level (e.g. comparing a project's emissions to a defined geographic area, or with projects that are similar in scope within a particular sector). It is recognized that technical difficulties may be attached to each of these benchmarks, and that data may not be readily available, but some meaningful methods for determining the significance of project's GHG emissions are necessary.

Proponents should consider the warming potential and significance of all GHG emissions produced from a project. Carbon dioxide, methane and nitrous oxide are perhaps more recognized as GHGs, whereas hydrofluorocarbons, perfluorocarbonss and sulphur hexafluoride are not widely acknowledged GHGs. The later three GHGs were not mentioned in the reviewed EAs. The type of GHG produced the by the project may be more or less significant, depending on its known ability to impact climate.

4) Proponents should consider GHG emissions in the design of projects.

Canada's commitment to the Kyoto Protocol and sustainable development should inform project design decision-making. Opportunities for emissions reductions and recovery should be considered at each stage of the EA decision-making process in order to design projects with the least GHG emissions and resulting impacts on climate change.

Guidelines Related to the Potential Impact of Climate Change on the Project

5) Proponents should identify all potential effects that climate change may have on their project, and undertake scoping exercises in order to determine the issues of greatest importance.

The resulting evaluation of climate change in EAs should be commensurate with the significance of climate change issues.

6) Proponents should address the cumulative forces of climate change on a project.

Currently, when EAs address climate change they are inclined to focus on distinct elements of climate change, to the exclusion of others. For example, streamflow may be identified as a component of interest, but modified evaporation rates as a result of climate change are not considered. The synergistic impacts of climate change are no doubt very comprehensive, with multiple components and forces, thereby leading to numerous uncertainties. However, proponents should be encouraged to identify as many interrelating forces that may be factors for a project as possible in order to prioritize and focus on the most important issues.

7) Proponents should include appropriate timeframes for climate change in EAs.

The lifetime of an operation should be considered in terms of how climate change may affect the project in future time intervals (e.g. 2030, 2050, and 2070). Climate conditions may cause more detrimental outcomes to the project infrastructure or impact predictions in fifty years, compared to thirty years. For example, the project may not experience significant impacts with a temperature increase of 2°C predicted for 2030, but may undergo considerable changes with a temperature increase of 4°C by 2070.

8) Proponents should consider the effects of climate change and the rate of structural deterioration to ensure that structures are able to withstand the effects of climate change over the life of the project.

As infrastructure ages, it may not be able to withstand the same forces (e.g. wind, water, ice) as it was when initially constructed. Therefore, it may be necessary to build more durable structures that are able to withstand a wide range of events (including long durations or increased frequencies of drought, flooding, extreme and/or surprise events).

9) Proponents should view climate change from a range of perspectives in all aspects of the EA decision-making process.

Addressing climate change from multiple perspectives is likely to reveal potential issues that would not ordinarily be identified. Climate change considerations may be important for project site selection, selection of alternatives, project design, and mitigation measures. For example, an evaluation of potential climate impacts may indicate that a wind farm may benefit from a different site location as a result of additional winds that are predicted to occur in particular regions as a result of climate change, or, a site may be deemed unsuitable for a hydroelectric project due to reduced streamflow as a result of climate change.

10) Proponents should consider engineering designs that respond to, or mitigate effects of climate change

Proponents should determine how projects may be designed to prepare for, and adapt to, climate change. Examples include the use of building materials and designs that will withstand a range of extreme weather events. Proponents should consider using engineered structures (e.g. geophysical membranes) for stabilizing structures instead of relying upon natural features (e.g. permafrost) that are contingent upon climate effects for durability.

Proponents should also consider designing projects in a manner consistent with predicted effects of climate change. For example, a hydroelectric project may be engineered to benefit from extreme rainfall if additional water storage capacity is built into the project design.

11) Proponents should develop contingency plans as part of a project to respond to the potential impacts of climate change

While it may prove economically prohibitive to incorporate numerous design changes into a project initially, projects should have contingency plans to respond to unforeseen changes in climate. An example may include well-constructed emergency response plans that prepare for "beyond worse case" scenarios.

12) Proponents should consider post-project monitoring related to climate change.

Post-project monitoring specifically related to climate change should be used to make adjustments in the project to reduce environmental effects, destruction of infrastructure, or financial implications. Projects subjected to EAs often have project design elements that rely upon the stability of physical features that are affiliated with climatic factors. For example, changes in temperature and precipitation are predicted to alter the soundness of permafrost, which is a structural component of a mine. Permafrost melting could result in a decline in structural integrity of the mine and a release of tailings, thereby causing potential environmental effects.

Proponents should monitor critical features over the life of the project (e.g. temperature of air, soil, and/or water, precipitation, and frequency and intensity of extreme weather events) to determine if project designs are responding to climate change as predicted. Monitoring ambient temperatures and temperatures of structures embedded in permafrost could ensure that appropriate mitigation measures are initiated to ease the outcome of a catastrophic event. The installation and monitoring of permanent weather monitoring stations near a project is another example of a post-project monitoring mechanism. Permanent weather stations that are consistently monitored contribute much-needed climate knowledge for the life of the project as well as provide regional knowledge of climate.

13) Proponents should give particular attention to projects relying upon water, located in water, or located in Northern Canada because these environments are predicted to undergo the most significant modifications in the environment as a result of climate change.

These projects are potentially the most vulnerable to climate change because northern climates are predicted to experience some of the most distinct impacts from climate change and aquatic environments may undergo a range of effects on streamflow, tides, winds, water chemistry, and water levels. Project viability, stability, design, and environmental impact predictions may be subject to great changes as a result of climatic changes. Their location may also necessitate additional safety contingencies given their potentially remote location.

Guidelines Related to the Potential Effects of Climate Change on Impact Prediction

14) Proponents should address the potential effects of climate change on impact predictions.

The review of EAs showed that only one of the eleven addressed the potential effects of climate change on impact predictions. The potential impact of climate change on VECs including fisheries, aquatic species, migratory species, vegetation, wetlands, ecologically significant flora or fauna, or land used by aboriginals for traditional purposes should be considered in EAs.

The EA review, combined with an examination of climate change literature, suggests there is a dearth of publicly available information upon which proponents may base predictions of this sort. However, over time, effective post-project monitoring strategies (in addition to increased examination in this field of climate change research) should assist in alleviating this information deficit. The Canadian Environmental Assessment Agency may also need to address this weakness using other mechanisms that could support EA (e.g. research and development, communication and dissemination of available data, establishing a climate change directorate within the Canadian Environmental Assessment Agency, etc.)

15) Proponents should consider the synergistic effects of climate change on impact predictions.

The effects of multiple changes in climate may act together to impact VECs. For example, rising sea levels and increased winds as a result of climate change may contribute to more extreme weather events. This factor may be important when predicting the potential impact that a spill from an offshore energy project could have on marine fauna.

Guidelines Related to Climate Change Uncertainties

16) Proponents should identify the uncertainties for each aspect of climate change that may impact the project.

17) Proponents should articulate the importance of climate change uncertainties for the project and provide evidence to this effect.

Methods used to determine the importance of climate change uncertainties should be clearly documented, with an explanation of the findings. The amount of resources allocated towards characterizing uncertainty should be proportional to its importance to the overall EA.

18) Proponents should clearly define uncertainty terminology.

Terms used to describe levels of uncertainty attached to specific findings should be defined. Terms such as "almost certain", "likely", "possible", "unlikely", "improbable", and "doubtful" often accompany "high", "medium", and "low" confidence predictions. However, these terminologies are used in different contexts, which invites multiple meanings. Therefore, these terms should be carefully defined to avoid incorrect interpretations. Consistency is a critical element for the terms used in the reporting of uncertainties in order to facilitate improved communication between research communities, decision-makers, and stakeholders. A statement of medium confidence (near 50%) that "warming trends could alter fish populations" is meaningless to the reader or decision-maker unless quantitative modifiers are added onto the degree to which warming could occur and the direction and severity of the alteration of fish populations.

19) Proponents should effectively communicate climate change uncertainties to relevant audiences.

The tendency in EAs is often to produce reports having very technical information. Since consulting lay people is a tenet of good EA practice, it is important for climate change uncertainty information to be discussed in an understandable and transparent way.

Recommendations for the Canadian Environmental Assessment Agency (the Agency)

Based on analysis of the 11 EAs, further issues for the Canadian Environmental Assessment Agency to consider have been developed in the following section. The themes identified center around the Agency's role in assisting proponents in addressing climate change effectively and consistently. Climate change presents very comprehensive issues for development that are subject to significant uncertainties. In order for climate change to be addressed in an effective manner that informs decision-making and advances the state-of-the-art in EA practice, it is recommended that the Agency take a leadership role on the issue of climate change. Therefore, it is suggested that the Agency provide additional technical support to proponents to supplement climate change guidelines for EA. Recommendations for this additional guidance are provided in the following section. The format of the recommendations encompasses general issues for the Agency to consider, GHG emissions, the potential effect of climate change on the project, the potential effect of climate change on impact predictions, and climate change uncertainties.

General Issues for the Canadian Environmental Assessment Agency to Consider

1. The Agency should provide substantial oversight and guidance to proponents for addressing climate change issues in EAs. Oversight should occur in conjunction with other government agencies involved in the EA, for reasons of consistency and effectiveness.
2. The Agency should provide a guidance document on climate change to proponents that addresses the potential for projects to impact climate change through the production of GHGs, the potential impact of climate change on projects, climate change considerations in impact predictions, and climate change uncertainties.
3. The Agency should develop and maintain a database of project EAs that have effectively addressed climate change in order to provide relevant examples to proponents that would assist in the preparation of their EA.
4. Consistent and relevant climate change information that reflects the current state of knowledge should be provided to all proponents.
5. The Agency should continuously seek to better the manner in which EAs consider all aspects of climate change by pursuing, encouraging, and disseminating expansive research on identifying climate change issues related to EA.
6. The Agency should provide guidance on climate change to proponents for similar projects (e.g. mining, hydroelectric, landfills, offshore oil and gas, etc.) Guidance tailored to projects within sectors typically subjected to EAs may help streamline scoping exercises. For example, mining activities typically have similar considerations for environmental impacts (e.g. effects on groundwater quality and quantity, VECs, decommissioning, monitoring, etc.). While these elements will be tailored towards site-specific conditions, some of the same issues will likely be consistently relevant across projects (e.g. hydrologic regime, tailings/containment ponds, etc.)
7. The Agency should communicate the importance of climate change to government agencies. For example, climate change working group could be established to inform review comments and decision-making on projects.

Greenhouse Gas Emissions

1. Best practices (including Life Cycle Analysis) for carrying out GHG emissions inventories should be provided to proponents.
2. Guidance should be provided to proponents on the individual GHGs (carbon dioxide, methane, nitrous oxide, hydrofluorocarbons, perfluorocarbons and sulphur hexafluoride) including global warming potential, effects on global warming, and activities associated with each GHG.
3. Resources should be developed to assist proponents in determining the significance of project contributions to climate change.

Potential Effects of Climate Change on the Project

1. In order to capture and encourage ongoing research into the effects of climate change in infrastructure, CEAA should consider developing a consortium that engages building associations, engineering, consulting and architecture firms, financial institutions, insurance companies, educational institutions, departments from all levels of government, members of the mining, hydroelectric, and energy sectors, and other bodies affiliated with project planning, construction, and operation. Included in such discussions should be issues of structural integrity over the life of the project, safety considerations, and contingencies.

The Potential Impact of Climate Change on Impact Predictions

1. Similar to the consortium recommended for addressing the effects of climate change on infrastructure, a group of climate change scientists, biologists, ecologists and other specialists could be organized to advance studies on the impacts of climate change on VECs.
2. Proponents should be given guidance on the types of environmental impact predictions that may be impacted by climate change.

Climate Change Uncertainties

1. The Agency should provide proponents with guidance in selecting appropriate uncertainty methods for EAs.
2. The Agency is encouraged to develop and provide to proponents best practices for the communication of climate change uncertainties to relevant audiences (e.g. the public and government reviewers).
3. It is advocated that the Agency develop a consistent body of experts that can assist proponents in characterizing climate change uncertainties and/or directing proponents to appropriate climate change resources as early as possible in the decision-making process.

Conclusions

The review of 11 EAs has demonstrated that current practice with respect to addressing climate change issues and associated uncertainties in EAs is lacking. EAs are not adequately addressing how projects may contribute to climate change through the production of GHG emissions; how projects may be affected by climate change; how the impact predictions of EAs may be affected by climate change and; climate change uncertainties.

One of the purposes of EAs is to identify environmental, social, and economic impacts of long-term developments. Given the many far-reaching potential impacts of climate change and the current Canadian policy direction involving climate change, it is advisable for EAs to incorporate climate change uncertainties into EAs and to amend project decision-making accordingly. It is necessary to provide proponents with guidelines for addressing climate change uncertainties in EAs in order to achieve consistent, comprehensive, and meaningful analysis. Such guidelines should address the potential for projects to impact climate change; the potential impacts of climate change on the project; the potential effects of climate change on impact prediction and; climate change uncertainties.

The Canadian Environmental Assessment Agency should also develop and disseminate appropriate supplementary resources to proponents at the earliest stage possible in the decision-making process in order to proactively address climate change and its uncertainties in EAs. New developments should be encouraged in climate change research that is relevant to EA and findings should be communicated to practitioners.

Appendix 4: Recommended Guidelines from Yeomans (2004)

From: Yeomans, J.S. Incorporating and Communicating Climate Change Uncertainties in Environmental Assessments. M.A.Sc. thesis, Toronto: Department of Civil Engineering, University of Toronto, 2004, Chapter 6.

Introduction

While numerous observers have recognized the potentially catastrophic consequences associated with a changing climate, several studies have indicated that the impacts and uncertainties of climate change have been inadequately addressed in project environmental assessments (EAs). Since project decision-making can be adapted in many ways to respond to climate change issues, project proponents are obliged to consider potential climate change impacts and uncertainties in their analysis.

This study has examined how various uncertainties from climate change can be analyzed, incorporated, and communicated within project EAs. Obviously proponents would need to modify the approaches presented to the situations faced within their specific EAs in order to include the relevant climate uncertainties into their own specific analyses. This final chapter concludes with a synopsis of the various suggestions and recommendations for accomplishing these tasks that have been discussed throughout the study.

Recommended Guidelines for Incorporating Climate Change Impacts and Uncertainties into an EA

In practice, most projects have been designed on the basis of historical conditions, but such historical specifications will not remain applicable under many of the conditions of a changing climate. Since there are numerous ways in which climate change impacts could be adapted to at the project level, these approaches and the extent of the possible impacts should be addressed during the project's EA. Consequently, there is a need in EAs for proponents to consider the potential impacts and uncertainties from climate change. However, the major difficulty for proponents is to determine both how changing climatic conditions could affect the project and how the project could affect climate change, and also how to effectively incorporate the resulting uncertainties into the EA. While there can be no definitive rule for selecting one approach for addressing climate change uncertainties over another, this section provides suggestions and observations that should be considered during the EA process.

1) The environmental effects related to climate change that should be examined at the project EA level need to be considered from three categorical perspectives:

1. the effects of climate change on the project;
2. the effects of climate change on the impacts resulting from the project;
3. the effect of the project on GHG emissions.

Direct climate change impacts on a project should be considered, since these are exactly the types of "environmental effects" that are studied in any project EA. Changes that a project may cause within the environment should be examined in relation to the state of the environment without the project and, since such changes may be affected by climate change, should be duly considered in its EA. Since a project directly contributes to climate change by either the production or the reduction of GHG emissions, estimates of the levels of these emission contributions/reductions needs to be made in the EA.

2) To estimate a project's effective contribution to climate change, its anticipated production of - or reductions to - greenhouse gas (GHG) emissions should be disclosed relative to its specific industry sector target.

While acknowledging that an individual project's contributions to global climate change may appear infinitesimal when viewed from a global perspective, each project's implications for climate change should be addressed in its EA. One reasonable surrogate estimate for these potentially wide-ranging impacts can be captured by the project's anticipated GHG emissions. By contrasting these GHG emissions relative to broad national industry sector emission reduction targets (for instance, the industry sector reduction targets specified in Canada (2002)), an effective proxy measure for the overall climate change impacts from the project can be provided. However, a complete life-cycle analysis should also be conducted in order to determine the full impact of the project on GHG emissions.

3) For a project EA, three major analytical methods that should be considered to evaluate the impacts and to incorporate the related uncertainties of climate change are:

1. scenario analysis;
2. probabilistic analysis;
3. sensitivity analysis.

While scenario analysis is the analytical method most often associated with climate change studies, sensitivity analysis and probabilistic analysis represent more general techniques that have been more widely used in addressing uncertainties. Depending upon the particular EA, each of the three methods, or various sequences and combinations thereof, could be deemed most appropriate for conducting a specific analysis. Proponents would need to be able to justify the specific choice of analytical method(s) to employ.

4) Key factors in the selection of an appropriate analytical method to evaluate the impacts and to incorporate the related uncertainties of climate change should include:

1. the measurability of the data;
2. the level of difficulty in using the method;
3. the level of modelling effort required.

A key factor in the choice of the specific analytical method to be used is based upon the nature of the measurability of the data. Hence, the applicability of a method can depend upon whether the values it requires as inputs are well-defined and quantitatively measurable or are only ill-defined and qualitatively measurable. The level of difficulty in the use of a method plays a major role in the appropriateness of its selection. Methods requiring significant use of resources (i.e. expertise, time, data, cost, computing) should not be used to study less important impacts. Methods requiring significant modelling effort necessitate the existence of a clearly developed level of understanding about the relationships between climate change and the specific impact (i.e. the existence of well-developed analytical models).

5) Two major factors that should influence the choice of the analytical approach for addressing climate change in an EA are:

1. the importance to the project of the specific impact being studied and the importance of the information resulting from the analysis;
2. the quality of the models that are available to study the impact and the quality of the quantitative data that is available for use in the models.

6) Scenario analysis should be the most appropriate approach when the quality of the model is high and quantitative data availability is substantial, and when the impact being studied is of significant importance to the EA.

Scenario analyses require more extensive computational effort, better developed models, and a better quality of quantitative data than sensitivity analyses. Hence, scenario analyses prove to be the most appropriate choice when the quality of the model is high, the quantitative data availability is extensive, and when the impact being studied is of major importance. These requirements will often be satisfied for impacts directly linked to climate change variables because of the extensive development of climate change scenarios that has already been performed by numerous international scientific institutes.

7) The first step in scenario selection is for proponents to identify exactly which scenarios meet the data requirements for the variables needed in their analysis.

The website for the Canadian Climate Impacts Scenarios (CCIS) permits proponents to download extensive scenario data of the possible future climate produced by various major international climate institutes. However, several of these scenarios either possess restricted sets of data or do not contain variable estimates covering all applicable future time periods. Therefore, proponents would necessarily be restricted to selecting data from those scenarios containing the information for all of the required climate variables over the time horizon of their analysis. Fortunately, summary information on the data availability of each scenario is provided by the CCIS.

8) Due to different scaling resolutions, proponents should ensure that the weather data taken from different scenarios contains the specific region in which their project actually occurs.

The size of specific regional grid references of the different climate institutes can cover dissimilar geographic regions due to the various non-uniform scale resolutions employed in scenario construction. Details on the different scale resolutions of the scenarios can be found on the CCIS website.

9) Should there be insufficient time to use all scenarios meeting specified data requirements, then it is important to select enough scenarios to bound the full range of scenario results for the relevant climate variables.

Since all of the climate change scenarios could occur, it is imperative for a proponent to consider a full spectrum of design options needed to account for the uncertainties in the decision process - including a due consideration for any "extreme" events. If circumstances prevent an examination of the project operating under all available scenario options, then proponents need to select specific scenarios that represent the extreme ranges of the key variables required in the analysis, as well as more moderate, intermediate scenarios. The CCIS website provides several useful suggestions for such restricted scenario selection.

10) In any study influenced by climate change impacts, it is essential to consider a range of different scenarios so that the distribution of possible outcomes can provide a useful context for understanding the relative likelihoods of various occurrences.

Once a proponent has determined which scenarios possess the needed variables over the required time periods, a decision must be made as to which scenarios to include in their EA. The scenarios should be selected in a fashion consistent with international methodologies. Namely, proponents should apply multiple scenarios that span a range of possible future climates and should include scenarios constructed by at least two different climate institutes. Reviewing as many scenarios as possible provides a broader context of what is likely to happen and how the key variables might change in the future.

11) Scenario analysis can produce an abundance of quantitative and graphical data that provides proponents with considerable information on the possible reliabilities and uncertainties that could be encountered by a project under alternate climate change futures.

Scenario analysis can be used to produce the representative range of climate change futures recommended by the CICS to support the analysis in EAs. The information produced by scenarios can be used to support the planning implications from using various different decision criteria for project design (such as: best-case-worst-case analysis, decisions based on averages or ranges of values), while simultaneously being used to answer questions on the environmental implications arising from such decisions.

12) Scenario analyses can be used in numerous ways to address different decisions and the information produced should provide data on the ranges, expectations, and uncertainties inherent in the project in the face of a changing climate. The values produced by evaluating a project design based upon the conditions of one scenario while operating under the conditions of several alternate scenarios could be used to provide estimates of the uncertainty in the performance of the project over the time horizon.

It can be of considerable interest to explore the consequences of making decisions based upon the use of any one scenario and determining the subsequent impacts should, in fact, any of the remaining scenarios actually occur. If these scenarios could be considered as representative of all possible future climate change paths, or at least their extremes, then the range of values determined in this output would provide the possible extreme. The determination of such limits could prove to be essential information in an EA.

Scenarios can be considered as representations of the best projections of future weather patterns that current scientific knowledge can provide and should, therefore, be considered as plausible representations of the range of probable futures resulting from climate change. Thus, it makes sense to consider these possible futures when making key decisions regarding a project's design.

Since no single scenario can be treated as more or less probable than others, the likelihood that any one scenario could occur would be the same as that for any other scenario. Hence, it would be quite reasonable to design a project on the basis of any one particular scenario and to investigate its performance over the entire time horizon under the assumption and conditions that every other scenario had, in fact, actually occurred. Therefore, the range of values and outcomes produced during such an analysis could provide an effective estimate of the uncertainty in the performance of the project over the applicable time horizon.

13) Proponents should practice vigilance against the adoption of a false sense of precision in finer resolution scenario data, since downscaled data, using some form of interpolation technique, has necessarily been employed in its creation.

Since any predictions of weather impacts on geographically-localized projects require the use of very detailed climatic information, the weather variables most needed for the majority of project EAs require very specific regional details. However, it is impossible for climate models to provide certainty about specific weather variables in specific locations due to the resolutions actually used in the scenario computations. The CCIS website describes how it is possible to downscale the coarser-scaled scenario data from the various climate institutes into much smaller grid references and does include scenario data expressed at much finer resolutions than that provided by the original scenario analyses. The CCIS provides numerous useful instructions, together with several caveats, on how to effectively employ this finer resolution data in an analysis.

14) To justify the significant development time, computational efforts, and economic costs needed for a probabilistic analysis, the importance of the impact being studied should be high.

Probabilistic methods require the existence of both well-developed models and well-defined, quantitative data for input into the models. Probabilistic analysis also requires considerable technical expertise and effort on the part of the user. Therefore, in order to justify the significant development time, computational efforts, and economic costs needed for probabilistic studies, the importance of the impact being studied should be high.

15) If an impact can only be measured qualitatively or cannot be defined probabilistically, then probabilistic methods should not be employed.

16) Sensitivity analysis can be an appropriate method when either the models and data required for the scenario and probabilistic methods are not readily accessible or when the importance of the studied impact relative to the project is low.

Sensitivity analysis can produce a good first-step in most analyses, since it can essentially be applied as an analytical screening device in virtually all cases. If the impact being studied can be shown to be of relatively minor importance, then additional analysis would not be required. Given its wide applicability, sensitivity analysis can provide the only choice when it is not possible to employ any other analytical methods. Thus, sensitivity analysis can prove to be the appropriate analytical method when either the models and data required for scenario and probabilistic methods are not readily accessible or when the importance of the studied impact to the project is relatively low. Unfortunately, sensitivity analysis cannot be performed on anything more than a very narrow set of parameters due to the combinatorial explosion in its computational requirements.

17) Proponents should use sensitivity analyses to identify which critical climate variables significantly impact their project and which project design vulnerabilities to focus upon given the inherent uncertainties in predicting the changes to these variables.

For a project, the proponent might want to determine the sensitivities that prove essential to effective decision-making. To perform this process, the proponent could employ expert judgment to select several key climate variables believed to have significant impact on the project and use sensitivity testing to determine whether a more detailed climate change evaluation was warranted. The proponent should involve both experts and stakeholders in the determination of which climate variables to actually test for sensitivity. If the thresholds of a few key climate variables that subjected the project to major sensitivities could be determined, then a subsequent examination of the vulnerability of the project to the uncertainties in these climate variables would be requisite. Knowledge of project sensitivities could direct additional impact/sensitivity studies to evaluate what potential design changes could be incorporated in order to adapt to or mitigate against the resulting vulnerabilities. Hence, sensitivity analysis can be used to identify the critical climate variables that could significantly impact the project and which project design vulnerabilities to focus upon given the inherent uncertainties in predicting the changes to these climate variables.

18) If pathologically extreme values for any climate parameter in a sensitivity analysis demonstrated no significant impact on a project, then this would indicate that the tested parameter need not be evaluated further in the EA.

In order for sensitivity analyses to become computationally manageable, numerous restrictive assumptions must be adopted for the key climate parameters and no singularly best process exists for specifying the steps in conducting sensitivity studies. The ranges and/or numbers selected for the climate parameters must be sufficient to determine whether their impact is significant in the decision-making process. If a sensitivity analysis used parameter values beyond those ever likely to occur (i.e. values representing pathological extremes) and demonstrated that these extreme values had no significant impact on a project, then this would indicate that the tested parameter was insignificant and need not be evaluated any further.

Recommended Guidelines for Communicating the Climate Change Uncertainties in an EA

Since stakeholders in EAs receive an open forum for expressing their opinions regarding any proposed management of environmental impacts, it is imperative that the uncertainties surrounding climate change be somehow effectively communicated to allof the disparate set of stakeholders. While numerous communication methods exist, a significant impediment to their widespread adoption in EAs is that to be understandable, most of these approaches require the stakeholders to possess sophisticated supplementary technical-skill proficiencies. Therefore, irrespective of the intrinsically obvious difficulties in communication and recognizing that stakeholders will always be drawn from diverse constituencies possessing dissimilar technical skill-sets, it is recommended that guidelines 19-33 be adopted in project EAs as the minimally prudent level of communication for climate change uncertainties.

19) The communication of the uncertainties about climate change should accomplish two fundamental tasks:

1. Clearly communicate the results of the analyses, including the range of impacts that might be caused by climate change;
2. Clearly communicate information about the degrees of belief in, and acceptance of, these results.

20) In order to accommodate the disparate technical-skills of the stakeholders, the presentation of information on climate change uncertainties should appear in the form of a comprehensive non-quantitative description written in an accessible, non-technical, clear, and concise format.

The issues of climate change should be considered in project EAs and the resultant uncertainties need to be communicated to stakeholders. Since the EA process can include an extremely broad spectrum of stakeholders possessing widely divergent technical-skills, perspectives and viewpoints, the existence of a universally applicable method for communicating climate change uncertainties is most unlikely. The goal of a non-quantitative written description must be to circumvent the technical-skill deficiency difficulties inherent in the stakeholders by clearly communicating the major uncertainties behind all of the key components in a format that is readily accessible to all stakeholders. Additional, ancillary methods can also be employed whenever their inclusion facilitates and supports the communication of the uncertainties with even greater clarity. Proponents should decide which methods are most applicable to their specific EA and these methods should be used when appropriate. However, proponents should only incorporate these additional methods with the recognition that their inclusion may not be well-understood by all stakeholders and a stipulation within the EA should indicate that these methods support the non-quantitative written descriptions, but are not replacements for them.

21) In addition to the non-quantitative written description, other methods and frameworks for communicating climate change uncertainties should be incorporated into an EA, if the proponent clearly believes that these methods provide ancillary support to the overall presentation of the analysis.

While non-quantitative written descriptions should be considered as the primary descriptive vehicle and the minimum required standard for communicating climate change uncertainties in EAs, their use need not preclude the additional application of other methods and/or frameworks. Several of these types of communication methods and frameworks are described in Chapter 5. However, these additional techniques are appropriate only when they can contribute broadly understandable additional support to the non-quantitative written descriptions without the need for technical-skill acquisition beyond the realm of the "common" stakeholder. Thus, proponents should be aware that communicating uncertainties to a diverse set of stakeholders using supplementary techniques might also require the concurrent addition of extremely detailed non-quantitative written descriptions in order for their actual meaning to remain accessible to the non-technical stakeholders.

22) If proponents employ methods for communicating information regarding the impacts of the climate uncertainties involved in their EAs beyond the non-quantitative written description, then they should carefully assess the technical sophistication level of the stakeholders in order to determine the appropriate means for communicating the information.

Proponents would need to determine whether the non-quantitative written description sufficiently captured and communicated the nature of the changes and impacts uncovered in their analysis or whether other presentation methods, or combinations thereof, might be more helpful to support an effective analysis. Alternate approaches to non-quantitative written descriptions might exist that could communicate the information to the EA's stakeholders more effectively.

Histograms and other similar graphical representations can provide an accessible visual representation of uncertainty in output data. Although not as visually appealing, tabular formats permit explicit side-by-side comparisons of outcome likelihoods under different assumptions of climate change and could include additional columns of historical likelihoods for comparative purposes. While tabular representations could prove difficult for stakeholders to comprehend, the actual information contained within them can convey considerably more analytical details than more visually accessible figures.

The approach(es) actually selected by the proponent would necessarily have to depend upon the complexity of the output, the type of information that had to be communicated, and the technical sophistication level of the interested stakeholders. Hence, proponents need to carefully determine the level of technical sophistication of the stakeholders in order to assess the appropriate means for communicating the climate change uncertainties discovered in their analysis.

23) Proponents may necessarily need to communicate the results of a probabilistic analysis using a combination of several different methods.

A probabilistic analysis provides challenges as to the appropriate way to convey the meaning of stochastic impacts, since simulation outputs tend to be expressed in the form of probability distributions rather than single numerical values. Sometimes the impacts can be best expressed as visual figures of the probability distributions, while at other times they might be better expressed numerically as average values or ranges. Hence, proponents may necessarily need to communicate their probabilistic analyses using a combination of more than one method.

24) Proponents should identify the key components in an EA and should articulate the nature of the major uncertainties inherent within each of these key components. Proponents need to provide non-quantitative written explanations concerning the acceptability of each of the key components identified for the EA. Namely explanations of:

1. the models used;
2. the data sets employed;
3. the major assumptions made;
4. the results achieved.

Detailed non-quantitative written descriptions are warranted only for the most significant elements and for the communication of their resulting uncertainties. Proponents should determine and communicate which models, data sets, assumptions, and results constitute the most important constituent elements, or key components, of the EA and the major uncertainties inherent within each of these key components. Hence, it is important for proponents to identify the key components in the EA and to articulate the nature of the major analytical uncertainties inherent within each of these components.

In order for the stakeholders to be able to assess their degrees of belief and confidence in both the resulting estimates of climate change impacts and their underlying uncertainties, non-quantitative written explanations should be provided concerning the acceptability of each of the key components identified for the EA. These are:

(i) the models used, (ii) the data sets employed, (iii) the major assumptions made, and (iv) the results achieved. Providing information about these factors will prove to be challenging, but the inclusion of clear and detailed summaries of each key component is particularly important in the non-quantitative written documentation. Sufficient care should enter into this process, to ensure that any technical meanings behind data presented in the description makes the underlying implication readily accessible to the layperson.

25) For each model that was used, the following interrelated information should be provided within the non-quantitative written description to help assess its degrees of acceptability:

1. its source should be identified;
2. the degree to which it is an accurate representation of reality should be stated;
3. whether it is based on an established underlying theory or school of thought;
4. whether the model has undergone peer review;
5. the degree of acceptance of the model by the overall research community.

26) For each set of data employed, the following interrelated information should be provided within the non-quantitative written description to help assess its degrees of acceptability:

1. the data source needs to be identified;
2. whether it is primary or modified (secondary, tertiary, etc.) data;
3. whether or not the data is based on an established theory or school of thought.

27) For each key assumption made, the following interrelated information should be provided within the non-quantitative written description to help assess its degrees of acceptability:

1. the degree to which it is an accurate representation of reality should be stated;
2. the degree of acceptance of the assumption by the research community should be ascertained.

28) For each set of resulting estimates, the following interrelated information should be provided within the non-quantitative written description to help assess its degrees of acceptability:

1. it should be stated whether these have been independently reviewed;
2. the degree of acceptability by the reviewers needs to be stated.

29) A summary assessment regarding the general level of overall confidence in each of the key components would also be requisite.

30) In order to convey uncertainties in quantitative information, where appropriate, the following types of summary information, expressed in an accessible non-quantitative written fashion, should be described within the body of the narrative (with the possible inclusion of supporting figures and tables):

1. mean values and variances of the estimates;
2. confidence intervals of the estimates wherever possible;
3. the ranges of the estimated values with an explicit note being made of the possible extreme values, in particular;
4. full probability distributions of the estimated impacts;
5. detailed descriptions of important thresholds and vulnerabilities that have been uncovered in the study;
6. descriptions of any other significant quantitative estimates determined in the analysis.

31) To support the inclusion of qualitative information, the following types of summary descriptions, expressed in an accessible non-quantitative written fashion, should be provided for the uncertainties (with possible supporting tables and/or other ancillary devices):

1. descriptions of the central tendency of the impacts together with any possible variation away from it, such as "most likely to have a medium impact with a significant possibility of attaining a high level";
2. the ranges of the estimate, perhaps described as "low to medium" ;
3. an explanation of any important thresholds and vulnerabilities such as "a possibly significant loss of a specified game species";
4. descriptions of any other significant qualitative impacts determined in analysis.

32) Whenever imprecise, qualitative terms and descriptors such as "low", "high", or "significant" have been used, the basis underlying their particular application should be clearly articulated in the non-quantitative written description.

For impacts that have been measured qualitatively, the uncertainties can only be described and presented with considerably less precision than occurs for the quantitative cases.

33) When estimated impacts result from a concatenation of several different components, proponents should provide an evaluation of the acceptability of each key individual component together with an overall assessment of their combination.

Whenever estimated impacts result from the product of a series or concatenation of components, the overall quality and acceptability of these results must necessarily depend on the combination of the quality of each of the individual models, data and assumptions involved. In order to communicate the acceptability of these combined results, an evaluation of the acceptability of each key individual constituent component would be requisite, together with an overall assessment of their combination.

3While the guidelines have been developed for a federal audience, they are also relevant for EAs conducted under provincial legislation. It is recognized that the participation of provincial agencies would be valuable in the development of climate change guidelines for EA.