First National Health and Climate Change Science and Policy Research Consensus Conference

Table of Contents

• The Conference
• Conference & Plenary Proceedings
• Research Agenda

The Conference

Health Canada hosted, in partnership with the Canadian Climate Impacts and Adaptation Research Network (C-CIARN) of Natural Resources Canada, the first Annual National Health and Climate Change Science and Policy Research Consensus Conference involving a wide spectrum of national and international researchers and policy analysts.

The Challenge

Health Canada, as the federal agency responsible for safeguarding and promoting the physical, mental, and social health of Canadians, will lead a national effort to produce interdisciplinary knowledge and evidence upon which all levels of government and health stakeholders can collaboratively build effective Canadian public health policies which will help our country to successfully adapt to climate change. The challenge is to produce a Research Agenda that shows the priority research questions, method development, and capacity gaps. The Research Agenda (Contact us to request a copy of report - available on this stite soon) )is for the use of Research Funding Agencies in setting calls for proposals.

The Context

Much is already being done to better understand the causes and long-term patterns of climate change and climate variability, and to reduce greenhouse gas emissions through the development and use of cleaner technologies. However, it is now recognized that these mitigation efforts cannot prevent climate change and its impacts from occurring. Our country will have to cope with and adapt to the many climate-related environmental changes which have already begun, and which will affect the future health and well-being of Canadians. People therefore need to know how climate change and variability can affect their health, what population groups are vulnerable, and how these new health risks can best be managed.

Climate change affects all ecosystems and social structures. To identify and manage its adverse effects will therefore require comprehensive risk management concepts and practices beyond the traditional "single issue" approach. Health and social science research must add climate change as a new variable as well as explore new integrative methods.

Results

Conference And Plenary Proceedings

Welcome and Objectives of the Conference
by Michael Sharpe, Health Canada

Integrated Assessment Framework
by Kristie Ebi, Electric Power Research Institute, U.S.

Policy Framework for the Management of Global Climate Change Issues
by Dieter Riedel, Health Canada

Climate Scenarios and Modelling: Use and Limitations in Health Studies
by Ian Rutherford, Canadian Institute for Climate Studies, University of Victoria, B.C.

C-CIARN and the Health Sector Node
by Eric Taylor, Natural Resources Canada

Canada Country Study: A Health Impact Assessment
Dr. Kirsty Duncan

Welcome and Objectives

• Michael Sharpe, Climate Change and Health Office,
  Health Canada

On behalf of Health Canada and its federal partners in climate change, Natural Resources Canada and Environment Canada, Michael Sharpe welcomed participants to the first-ever conference in Canada that concentrates on building a research agenda on health and climate change. He said Health Canada would like to see this event occur annually, and emphasized its focus on consensus-building.

Sharpe stated that the conference was concerned with increasing understanding of the sensitivities and vulnerabilities of the human system to all elements of climate change, and of humans' adaptive capacity to adjust to climate change.

Timing is everything in the study of climate change, Sharpe stressed. Over the past 10 years, climate scientists have developed a better understanding of the physical factors that influence climate change and climate variability. They have also improved the technology used to assess how the global and regional climate might change. Now it is possible to study how health mig ht be affected across regions and sub-population groups.

The purpose of this conference is to bring together scientists and researchers from diverse disciplines to identify the work that needs to be done, the research gaps that currently exist, and the questions that should form the research agenda for the next several years. Sharpe noted that the research agenda can be used to alert governments, research funding agencies and other groups whose support is needed to get the work done.

At each annual conference, he explained, the research agenda developed this week will be revised. The goal is to keep building a foundation of scientific and experiential evidence that will be used as input to a Canada-wide policy and planning conference each September.

Turning to the conference agenda, Sharpe explained that the morning presentations were intended to raise awareness of new methods, data sources and research disciplines with which health and social researchers and policy analysts are not familiar, and that they must learn to incorporate into their work. He stressed the need to move from a multidisciplinary research focus to a truly collaborative, interdisciplinary focus and ultimately to a transdisciplinary agenda, leading to new models that can explain some of the new problems facing climate researchers.

Sharpe cited a model in a US Environmental Protection Agency (EPA) document that showed the interactions between atmospheric and ecological systems, suggesting that the physical climate model reflected the world of climate change research and policy-making as it has been conducted so far.

While the model considers human activity as a factor, he stressed the need to distinguish the dynamics of health and well-being from the broader categories of human activities and physical climate systems if the human half of the climate change equation is to be properly understood.

Turning to a table used by the World Health Organization (WHO) and the US EPA to categorize the direct and indirect sensitivities and vulnerabilities of health to climate change, Sharpe noted that Health Canada has added two key areas for examination: Population vulnerabilities in cities and communities, and health and socioeconomic impacts. The new categories reflect a desire to ensure that social sensitivities are included in the discussion, and that the adaptive capacity of potentially affected sub-populations in Canada is adequately explored.

Sharpe mentioned that the conference proceedings will be posted on the Health Canada website (www.hc-sc.gc.ca) throughout the conference, and that the final research agenda will be posted by next week. He outlined the questions that will be discussed in each workshop session:

1. What are the strengths and limitations of the current state of knowledge, methods, data sources and capacity?
2. What are the missing gaps in knowledge, methods, data sources and capacity?
3. Over the next five years, what are the research questions that need to be answered to start filling the gaps and limitations in knowledge, methods, data sources and capacity?
4. Is there a need for a central health sector node to support all health issue networks? Is this the best way to ensure that everyone is kept informed and engaged from this point on?

Presentations

Integrated Assessment Framework

• Kristie L. Ebi, Ph.D., MPH,
  Electric Power Research Institute

Kristie Ebi cited methodological limitations as a reason that those working to estimate the health consequences of climate change may want to move away from traditional, science-based Quantitative Risk Assessment (QRA). Since QRA requires a specific baseline in order to effectively measure change, she said the method is inapplicable in the absence of underlying assumptions, and may not be useful in estimating health consequences. Further, the method is not set up to deal with multiple factors and rarely considers multiple and/or interacting risk factors, particularly in terms of indirect effects. It is of limited use in facilitating understanding or in the assessment or projection of impacts; it does not consider feedback mechanisms; and it cannot accommodate uncertainty about the magnitude, timing and nature of changes in climate and socioeconomic systems. These are important limitations when the goal is to determine health changes, an undertaking fraught with uncertainties.

Ebi listed a number of models that can be used to assess the potential health consequences of climate change. Empirical-statistical models can extrapolate climate/disease relationships across time and geography, process-based models can be derived from accepted biophysical theories, and economic models can project likely effects using economic values.

A fourth option, integrated assessment, is very much in the eyes of the beholder and can be done at different levels, Ebi said. The model supports both policy and research through a cause-effect-interaction systems approach that combines, interprets and communicates knowledge from diverse scientific disciplines. Integrated assessment makes it possible to evaluate a whole set of cause-effect interactions from a synoptic perspective with two characteristics: it should have added value compared to an assessment based on a single discipline, and it should provide useful information to decision-makers.

The purpose of integrated assessment is to synthesize multidisciplinary knowledge to inform policy and decision-making, rather than advancing knowledge for its intrinsic value, Ebi said. As a systems-based approach, it is designed to facilitate understanding of complex problems, largely by generating insights that are difficult or impossible to achieve from traditional, unidisciplinary research.

Two basic types of methods are used: analytical and/or statistical, and participatory and/or qualitative. Either way, Ebi said, integrated assessment sheds light on complexities through an understanding of the interactions and feedbacks within an entire system - for example, by placing climate change in the context of other key drivers of health status and evaluating how different adaptation measures might change the system response. In this way, the model enables researchers to explore uncertainties and prioritize research needs.

With integrated assessment, Ebi said, framing the research question is particularly important. There must be clarity about why the assessment is being done, who the information is for and how the results will be used. An integrated assessment development process is an ongoing circle of information-gathering that includes a clear definition of the problem, conceptual modelling, quantitative modelling of uncertainty, and sensitivity analyses or experiments, assessment and, finally, policy recommendations.

Whereas traditional models tend to focus on quantitative issues, integrated assessment begins with the development of a conceptual framework before filling in quantitative estimates, and clearly shows the inter-relationship between quantitative and qualitative factors. Ebi cited the "Analytica" Model software as an example of an integrated assessment framework that supports an array of component modules, each with mathematical representations of cause-effect relationships. Qualitative estimates are used when necessary, and modules are linked to show the links and feedback mechanisms among key components. The resulting model can be used to identify research gaps that frequently occur when an issue crosses disciplinary boundaries.

Ultimately, Ebi said the strengths of the integrative assessment model include its ability to put climate change into perspective with other key drivers of health status, explore interactions and feedbacks including adaptations, study the effects of uncertainties, provide a framework for understanding scientific knowledge, including prioritizing research needs, and support effective communication. Its limitations include the high level of integration required, the accumulation of uncertainties because of extensive modelling, and limited opportunities for calibration and validation.

Questions

A participant asked whether the significant uncertainty in each section of the i ntegrated assessment model would preclude meaningful policy outcomes. Ebi said it is important to balance concern about uncertainties in the model with the reality that policy will be made regardless. With an integrated approach, she added, the health sector will at least have an opportunity to sit at the decision-making table. An audience member agreed with Ebi, adding that uncertainties can be minimized by coming at the question under investigation from a number of perspectives. The result of the various studies will give a quick measure of whether outcomes are robust.

A delegate asked how values and applied ethics fit into the integrated assessment model. While the answer depends on how a research question is framed, Ebi said experience points to a strong sense of ethics. When discussion centres on rising sea levels that may result in the drowning of an island, the issues at hand are clearly social as well as scientific.

A participant reported that Environment Canada is currently undertaking an integrated project on the impacts of climate change on the ecosystem. The project will address linkages like the impact of increased use of road salt on climate change. Participants can find details online at
www.utoronto.ca/imap.

Policy Framework for the Management of Global Climate Change Issues

• Dieter Riedel, Health Canada

Dieter Riedel informed participants that over the past 25 years there have been a series of environmental crises, including problems related to acid rain, smog, ozone-destroying chemicals and the long-range transport of toxic substances. These problems have been caused by environmental pollution and have raised major concerns about ecosystems and human health. In each case, the precautionary approach was used to manage risks, and research was needed to clarify ecosystem and human health risks and to find effective measures for managing risks. The need for collaboration at many levels is one of the lessons that was learned in trying to manage these crises. Health Canada also learned that the government is not always the best risk manager - citizens and experts have a great deal to add to such initiatives. The experience gained in managing risks in the past is now being applied to managing the risks associated with climate change.

Turning to the health implications of climate change, Riedel told participants to expect a mixed bag of direct and indirect, short- and long-term environmental health effects. What needs to be assessed is the vulnerability of ecosystems and of human population groups, as well as the full range of implications (including the costs and benefits) of mitigation and adaptation measures.

Assessing health implications, he continued, is a complex task, requiring a wide range of knowledge, skills, information and databases. Riedel informed participants that there currently is no single standard method for undertaking assessments. Efforts are underway at the World Heath Organization (WHO) to develop climate change health impact assessment guidelines. A framework for assessing and managing climate change issues will also be helpful.

Climate change is shaped by natural mechanisms that affect the distribution and intensity of environmental health change risk factors, including insects and chemicals. The process of climate change is long. There are slow, direct and indirect ecosystem effects, as well as unknown factors that influence risks. The management of climate change and related risks at all levels requires comprehensive, trans-disciplinary and cross-sectoral knowledge so that policy strategies can be developed at the various levels. There is a need to recognize the international scope of climate change risks and work collaboratively to understand the climate change process.

The Canadian government has drafted a "Policy Framework for Managing Global Climate Change Issues". The Framework was drafted by external experts and is based on the US Framework for Environmental Health Risk Management (FEHRM). Riedel elaborated the six interactive stages of the framework, noting that Health Canada plays a central role in the climate change risk management process:

1. Define the health, socioeconomic, technical and political context and problem(s), and assess the relevance to affected stakeholders.
2. Characterize hazards and likely indirect and direct health impacts from expected environmental change.
3. Develop mitigation and adaptation options based on precautionary and equity principles and consultation.
4. Assess risk predictions and uncertainties, socioeconomic inputs and public input. Formulate and choose practical, flexible risk policies and strategies based on broad support through consultation.
5. Implement national and international risk management policies and strategies for mitigation and adaptation.
6. Evaluate the progress and effectiveness of actions by monitoring changes in risks via a broad range of indicators of health and well-being, and revise policies and strategies as needed.

Riedel concluded that extensive networking, consultation, partnership and communications are needed to manage climate change risk.

Climate Scenarios and Modelling: Use and Limitations in Health Studies

• Ian Rutherford, Canadian Institute for Climate Studies,
  University of Victoria, BC

Rutherford outlined the use of climate scenarios in impacts assessments. Climate scenarios help researchers understand the physical climate system using sensitivity analyses. These can identify responses to specific past events, and provide information about possible future climate conditions. There are several ways of constructing scenarios:

• A new climate scenario could be constructed from existing climate records. It would provide some information, but it would be a crude scenario.
• "Climate analogues" can be used to identify particular climate events in order to determine possible response to impacts.
• Scenarios can be generated from general circulation models (GCMs).

Rutherford explained that GCMs are the "only credible tools currently available for stimulating the physical processes that determine global climate," according to the Intergovernmental Panel on Climate Change (IPCC). They use mathematical formulae (algorithms) to model physical processes which can be highly non-linear and interactive. The GCMs have been very well developed over the last 40 years, progressing as mathematical techniques and computer power became more advanced. It is now possible, essentially, to simulate climate by calculating the weather.

A wide range of forcing (socio-economic) scenarios are available. The ones most commonly used wre developed by the IPCC.. Researchers integrate socio-economic scenarios into the climate model in order to project different possible outcomes. However it is not yet possible to integrate socio-economic and climate factors in order to see the full range of possible effects that they may have on each other.

GCM scenarios can be run with and without information about sulphate aerosols. Rutherford noted that the direct effect of aerosols acts counter to that of greenhouse gases because aerosols have a cooling effect. However there is still uncertainty over the indirect effects. For example, aerosols can change the degree of cloudiness, which in turn may have other effects on the climate.

Rutherford emphasized the IPCC recommendation that "users should design and apply multiple scenarios in impact assessments, where these scenarios span a range of possible future climates, rather than designing and applying a single 'best guess' scenario." He added that there is a range of variability predicted by different models that run with different forcing scenarios.

He then outlined the project aims of the IPCC. These include providing basic climate change scenarios and fostering a capacity in the community to work with these scenarios. Scenarios for Canada are drawn from "warm start" experiments, and are done with and without sulphate aerosol forcing, using an IS92a-type forcing scenario. Scenarios extend to 2100, and the models are included in int erna tional model intercomparison exercises.

The Canadian climate scenarios of the Canadian Institute for Climate Scenarios (CICS) website at (www.cics.uvic.ca/scenarios) show climate scenarios for Canada from GCM experiments using IS92a-type forcing. The scenarios are done at the original GCM resolution of 400 kilometres. Monthly, seasonal and annual values are also available. A number of climate variables are considered. The above-cited CICS website at the University of Victoria also offers advice on scenario construction and use. Elements that are nearing completion include: monthly scenarios; simple interpolation of change fields to 0.5° latitude/longitude resolution; and scenarios for CGCM2 experiments. Also available on the website are maps that provide a visual picture of the overall pattern of results and the scale of resolution.

Some of the information not available from the CCIS project includes observed climate data (although this can be found through links available on the website), and daily GCM data (which can be obtained by contacting individual modelling centres directly). Additional scenarios are also available from international sources that have created their own models (e.g. in Australia, Germany, the US and Japan).

Rutherford showed a graph representing the range of results from different models for different areas, noting that the smaller the area, the more dispersion and uncertainty there is in the results.

This spring, the IPCC will be doing summaries of the climate scenarios that are available, as well as some intercomparisons and some exploration of the significance of the climate changes projected in the different models. Future plans include continued updating of the collection of scenarios and interpretation of scenario information.

Rutherford outlined some of the limitations of the scenarios with respect to health studies. There is a lack of directly modelled information for some variables, such as air and water quality. Variables such as ground-level ozone, particulates and smoke, and sulphur and nitrogen aerosols are not available in these climate simulation scenarios. Researchers need to find creative ways of getting the information (for example, by looking at the socio-economic factors that were used to drive the climate scenarios). Researchers will have to look elsewhere for other information, such as soil moisture, lake and ground water levels and water quality. The models also lack full simulation of stratospheric ozone. One factor that is available in principle, but may in practice be lacking, is extreme weather information.

There is also "a whole family of secondary effects" that are not shown in these models. Impacts of climate change on non-climate variables include changes in natural vegetation patterns and water availability. Impacts related to climate change adaptation and/or mitigation include changes in agricultural practices and fossil fuel use. Some of this information may be available from the associated forcing socio-economic scenario. Rutherford suggested that, when taking results from climate change models, researchers "be aware of the socio-economic projections and factors" built into those models.

Questions

A participant asked about the role of air trajectories in spreading disease. Rutherford said information on surface winds is now available from many models, and can be used to construct trajectories.

Another participant noted that GCMs are very large-scale: in one model, the Great Lakes did not exist; in another, Florida was missing. This makes it hard to understand the health effects of climate change at the regional level. Rutherford agreed that researchers must take this issue into account, recognizing that small-scale results could depend on larger-scale trends or be independent of those patterns. Some researchers are now trying to run highly detailed models in a core resolution nested within a larger one. But even a 50-kilometre resolution is relatively large-scale and overlooks smaller regions, such as mountain valleys.

Asked about the progress of Canada and other nations in constructing regional models, Rutherford said the Université de Québec à Montréal is working at a 50-kilometre resolution. Models at a much smaller resolution are possible in principle, but will not be in place for a few years. Groups in the US and elsewhere are working on regional models, and an effort is under way to compare the various models in relation to a standard area.

Asked why it takes so long to develop new models, Rutherford explained that the process calls for a computer-driven approach. Advances depend on the development of new algorithms and the availability of increased computing power. The problem is that the models are four-dimensional (including space and time), and therefore require 16 times more computer power to double the resolution. About a dozen groups around the world are working on climate change models, he said, but "it's slowly coming".

A participant asked to what extent simulation modelling has taken into account the possibility that ecological systems may absorb a certain degree of pressure and then suddenly flip: "Do models take into account that we could go from a warming trend into a sudden deep freeze?"

Rutherford responded that, in principle, the models take this into account. Experiments have been done that show this kind of behaviour, but only under very extreme circumstances.

One possible effect is a change in the Gulf Stream that carries warm water into northern latitudes and moderates temperatures in Europe and Scandinavia. The phenomenon depends on a delicate balance in which cold water sinks to lower depths and is carried south. Some theories hold that changes in salinity due to warming in the Arctic regions could increase the buoyancy of the colder water, so that the return circulation is reduced and the Gulf Stream is cut off. This would plunge northern Europe into a new ice age.

Rutherford said researchers are currently running climate models to simulate the onset of an ice age, as a means of understanding the fluctuations and instabilities involved.

C-CIARN and the Health Sector Node

• Eric Taylor, Natural Resources Canada

Eric Taylor traced the development to date of the Canadian Climate Impacts and Adaptation Research Network (C-CIARN) and invited participants to consider the value of forming a health node within the network. Noting that full implementation of the Kyoto Protocol will only postpone a doubling in atmospheric carbon dioxide concentrations by eight years, he stressed the need for a pragmatic look at how climate change will affect the country and how Canadians can adapt over the next 30 to 50 years.

C-CIARN's key objectives are to improve coordination within the impacts and adaptation research community, provide greater visibility for climate change issues, encourage stakeholder involvement in impacts and adaptation research, distribute information to communities, governments and industry, involve a broader range of researchers in climate change, and provide assessment for climate change impact assessments. The network is expected to include a series of regional nodes, as well as sectoral nodes dealing with water resources, forestry, coastal zones, agriculture, landscapes, fisheries and health. Each node will be facilitated by a one-person office that will receive up to $125,000 in federal funding. Taylor suggested that a health node could include participants from university medical departments, Health Canada and other federal departments, provincial and territorial departments and agencies, private sector companies and associations, non-governmental organizations, and First Nations.

Questions

A brief discussion period touched on the need for coordination among the regional and sectoral nodes, and the difficulties which some participants might have in deciding where to allocate their scarce time and attention. Taylor said it should be possible to coordinate efforts, citing one researcher whose work had been useful to his regional node as well as his sector of expertise. Kristie Ebi stressed the value of a structure that would capture the interactions among areas of expertise, suggesting that it might otherwise be difficult to capture issues like the impact of changing water systems on health. Michael Sharpe said t he regional nodes can facilitate work at the regional and local level. "It's workable, and it's facilitating our work at Health Canada," he said. "While we're working nationally, we still have to facilitate and get work done at the local level, and then integrate it at the national level."

An audience member urged C-CIARN to deal with political and international aspects of resource management. Sharpe said CCHO is already in touch with the US EPA and some components of the Health and Human Services Administration to discuss cross-border research opportunities. The next step will be to get ministries of health in other countries involved at the policy level in partnership with the World Health Organization.

Canada Country Study: A Health Impact Assessment

• Dr. Kirsty Duncan

Dr. Kirsty Duncan gave an overview of health impacts identified in the 1997 Canada Country Study (CCS), with updates to reflect the 2001 report of the Intergovernmental Panel on Climate Change (IPCC). While underscoring the uncertainties around climate change, she stressed that the 1.0-3.5°C change in average global temperatures projected by the IPCC in 1995 would be dramatic. A temperature reduction of 2-4°C would be enough to bring on an ice age that covered half the planet, she said and "+3°C over the coming century would be an unprecedented rate of rapid change for the world's human population." The IPCC's latest report refined the projection to a range of 1.4-5.8°C.

For southern Canada, researchers anticipate warming of 4-8°C. In the North, the range is 0-6° in summer and 8-12°C in winter. "These changes will clearly have a direct and indirect impact on the health of Canadians."

She said the following direct effects could result from climate change:

• Increased frequency and severity of summer heat waves could lead to increases in illness and death, particularly among the young, the elderly, the frail, the ill, "and especially among those living on the top floor of apartment buildings who lack access to air conditioning." She stressed that heat waves will affect many causes of death, not only cardiovascular and respiratory ailments. Adaptive measures will include increased use of air conditioning, increased uptake of fluids, and establishment of community warning systems and action plans.
• Cold waves will be less frequent. Saskatoon, which currently expects three days below 35°C each year, will see only one such day every four to five years.
• Climate change is expected to increase the frequency of severe lightning, thunderstorms and hail storms. Tornadoes are expected to be more frequent on the prairies, and warmer winter temperatures are expected to increase the incidence of freezing rain and possibly ice storms. It will be impossible to predict where they will occur, or to identify vulnerable populations.
• Flooding is already the deadliest form of natural disaster in the US. Disaster workers are at risk of injury during a flood, and are susceptible to post-traumatic stress, anxiety, and even suicide in the period that follows.
• Flooding is expected to become more frequent. Any river could be susceptible, and nearby populations could be vulnerable.

Indirect effects could include the following:

• Climate change is expected to affect the distribution of vector- and rodent-borne diseases like encephalitis, malaria, Lyme disease or hantavirus. While most people expect public health measures to counter any increase in disease, Duncan reminded participants that a "great malaria region" existed between London, Ont. and the US border as recently as 1873. As late as 1890, the American north recorded 1,000 malaria deaths per 100,000 population. While dengue and yellow fever are unlikely to expand northward, she noted that a 1993 hantavirus epidemic in the US Southwest was linked to prolonged rainfall associated with the 1991-92 El Niño event.
• Water-borne diseases already affect about nine million Americans each year, with symptoms ranging from mild gastro-intestinal illness to death. Giardia and Cryptosporidium have already infested US and Canadian watersheds, and Victoria was the site of the largest-ever outbreak of toxoplasmosis. Warmer waters will likely lead to the development of toxic organisms associated with different kinds of poisoning. A 1987 outbreak of shellfish poisoning in PEI was linked with an El Niño event, and the Walkerton tragedy brought home the broader impact of water safety and water treatment issues.
• Smog, acid precipitation and particulates will likely worsen as a result of a warmer climate. More than half of Canadians live in areas where summer concentrations of ground-level ozone exceed maximum standards. Vulnerable populations include the young and the elderly, and anyone with cardiovascular disease, asthma, emphysema or bronchitis. Air quality problems are linked to increased hospital admissions, and acid precipitation can affect lung growth, development and function in children. Adaptive measures include federal and possibly provincial legislation, as well as warning systems for the entire population, but especially for those who are most vulnerable.
• Melting glaciers could lead to increased flooding of coastal wetlands, including the Hudson Bay lowlands, Vancouver, and St. John, NB. This, in turn, could mean salt water intrusion into groundwater, inundation of water distribution systems by rising water tables, and flooded treatment plants. At the same time, lake levels are expected to decline. The Great Lakes could experience lower water levels of 0.5-1 metre and related water quality problems for four out of every five years.
• Nutritional health could be affected by viral, parasitic and bacterial diseases in imported foods. First Nations will also see shifts in the distribution of vegetation, fish and wildlife, leading to changes in subsistence livelihoods.

"Warming over the next century will be the most rapid in the past 10,000 years," Duncan concluded.

"We can take some adaptive measures now. Other measures will have to wait until climate change starts to happen." But she stressed that adaptation costs money, that the cost will depend on the speed with which the climate shifts, and that the effectiveness of adaptive measures is not yet known.

Questions

A participant asked whether the human health research in the Canada Country Study had been updated in the past four years. Duncan said only about 25 empirical studies have been carried out in Canada, so that most of the material in the CCS had to be drawn from elsewhere.

A couple of audience members said the short-term positives associated with climate change should be acknowledged alongside the negatives. "Otherwise, we lose credibility," one participant noted. "People have an intuition that there is good from global warming too and, unless we address that, we're not going to be heard about the seriousness of the longer-term consequences." Duncan agreed that the participant had described an important communication challenge, but explained that the IPCC must limit itself to reviewing the existing literature on health and climate change - almost all of which focusses on the negatives. She suggested that this might be an important item for the Climate Change and Health Office (CCHO) agenda.

The group discussed the decline in cold-weather mortality that might result from climate change, with Duncan noting that severe winter weather currently kills 10 times more Canadians than the summer heat. A researcher with experience in the area said the comparison is accurate, but warned that no one can predict how climate change will shift the ratio.

An agrifood industry participant warned that the focus on negative data could lead to sensationalized media coverage and public fear-mongering, and suggested that food quality problems in the US might create opportunities for Canadian growers. With a 4-8°C temperature increase, he said, Ontario can open banana plantations and lead the world in climate change adaptation.