Synthesis - Ontario

Climate change presents challenges for Ontario's ecological, social and economic systems. In many parts of the province, changing climate is having noticeable impacts on natural and human systems. Such impacts include decreases in the duration of lake-ice cover, increases in some climate extremes, and shifts in aquatic and terrestrial ecosystems. Recent social and economic impacts resulting from shortened winter road seasons, increased forest fire risk, lower Great Lakes water levels, disruptions to winter tourism activities, and more frequent smog episodes and extreme heat events illustrate that these systems are both sensitive and vulnerable to the type of climate conditions that are projected to occur more frequently in the next 20 to 50 years.

Although the magnitude and timing of projected climate change vary across the province, Ontario will experience impacts in virtually every economic sector. Adaptation responses to address these impacts will require consideration of both the potential economic, social and environmental consequences of climate change and the probability that these impacts will be experienced within the planning horizon. Table 5 summarizes the major negative impacts by subregion, and the general time frame when these impacts are expected to become problematic for social and/or economic systems. Opportunities presented by changing climate, as described previously for agriculture, warm-season tourism and other sectors, are not included in the table but will require some degree of adaptation in order to realize maximum benefits. Although there remain significant knowledge gaps regarding the vulnerability of some systems, there is generally sufficient knowledge to identify short-, mid- and long-term priorities and to implement no-regrets adaptation actions (see Chapter 10).

Since anticipatory adaptation requires the use of predictive information, risk management offers a practicable and credible approach for defining measures to achieve acceptable levels of societal risk (Bruce et al., 2006). An example of how this approach, based on the Canadian standard Risk Management: Guidelines for Decision-Makers (Canadian Standards Association, 1997), can be applied through a series of clearly defined steps is found in Adapting to Climate Change: A Risk-Based Guide for Ontario Municipalities (Bruce et al., 2006; Box 4).


Major negative impacts of climate change and onset of ‘problems' by subregion in Ontario.
Cumulative stresses/region Subregion
North Central South
Fish Present to 20 years Present to 20 years Present to 20 years
Fauna Present to 20 years No information on timing Present to 20 years
Flora Present to 20 years No information on timing No information on timing
Quality 50 to 80 years 20 to 50 years Present to 20 years
Quantity (shortages) No significant impact expected No significant impact expected Present to 20 years
Flooding Present to 20 years Present to 20 years Present to 20 years
Heat No significant impact expected 20 to 50 years Present to 20 years
Insect/vector disease 50 to 80 years 20 to 50 years Present to 20 years
Water quality 50 to 80 years 20 to 50 years Present to 20 years
Air quality No significant impact expected 20 to 50 years Present to 20 years
Drought No significant impact expected No significant impact expected Present to 20 years
Increased demand No significant impact expected No significant impact expected Present to 20 years
Lower production No significant impact expected No significant impact expected 20 to 50 years
Fire Present to 20 years Present to 20 years No significant impact expected
Pests and disease 20 to 50 years 20 to 50 years No significant impact expected
Winter roads Present to 20 years No significant impact expected No significant impact expected
Paved surfaces No significant impact expected No significant impact expected 20 to 50 years
Navigation No significant impact expected 20 to 50 years 20 to 50 years
Tourism and Recreation
Cold season No significant impact expected Present to 20 years Present to 20 years


Steps in the risk management process
(from Bruce et al., 2006)

"Risk management is a systematic approach to selecting the best course of action in uncertain situations by identifying, understanding, acting on and communicating risk issues. In the context of adapting to climate change, risk management provides a framework for developing adaptation strategies in response to potential climate changes that create or increase risk. …whether the issue is as large as a municipal strategic plan for climate adaptation or a smaller study around specific issues such as extreme rainfall events, heat, health issues or others, the risk management process will guide staff towards the optimal solutions. "
(Bruce et al., 2006, p. 6)

Step 1: Getting started

  1. Identify the specific problem or hazard and the associated risks.
  2. Identify the stakeholders and the project team, especially those with the relevant expertise.
  3. List the responsibilities of each member of the project team and the resources needed to complete the risk management framework.
  4. Draft the work plan and estimate the schedule.

Step 2: Preliminary analysis

  1. Define the climate-related hazard and the potential risks that may cause harm, in terms of injury, damage to property and/or the environment, or monetary losses to the community.
  2. Identify possible outcomes from the risk situation.
  3. Conduct a quick overview of the process to help determine the complexity of the project, the probable time-frame for completing the work and a sense for whether the project team and resources assigned are sufficient.

Step 3: Risk estimation

  1. Identify the frequencies and consequences associated with each of the risk scenarios.

Step 4: Risk evaluation

  1. Develop a process for comparing or ranking each risk scenario.
  2. Evaluate the risks by examining them in terms of costs, benefits and acceptability, considering the needs, issues and concerns of stakeholders.
  3. Identify unacceptable risks and prioritize them for risk reduction or control strategies.

Step 5: Risk controls and adaptation decisions

  1. Identify feasible strategies for reducing unacceptable risks to acceptable levels.
  2. Evaluate the effectiveness of the adaptation or risk control strategies, including the costs, benefits and risks associated with the proposed adaptation measures.
  3. Select the optimal adaptation or risk control strategies and consider the acceptability of residual risks.

Step 6: Implementation and monitoring

  1. Develop and implement the adaptation plan.
  2. Monitor and evaluate the effectiveness and costs of the adaptation responses.
  3. Decide to continue or terminate the risk management process.

Of particular importance are planning decisions involving physical infrastructure, which involve large capital investments and, by virtue of their anticipated lifespan, will have to be resilient to changes in climate parameters across many decades. The construction industry, building codes and standards, and land-use planning are all slow to change, and decisions pertaining to land use and building materials are often dominated by short-term commercial interests (Auld and MacIver, 2005). Adaptation with regard to infrastructure will have to consider the variable life cycles of structures and replacement cycles (Table 6), in conjunction with projected changes in climate (Auld and MacIver, 2005). Updating of existing codes and standards using trends evident in historical climate records represents a potential starting point in reducing infrastructure vulnerability (Auld and MacIver, 2005, 2006).


Infrastructure life cycle timeframes (adapted from Auld et al., 2006).
Structure Phase Typical expected life cycle timeframe (years)
Commercial buildings Retrofit
Roads Maintenance
Reconstruction or major upgrade
Bridges Maintenance
Reconstruction or major upgrade
Rail Major refurbishment
Reconstruction or major upgrade
Airports Major refurbishment
Reconstruction or major upgrade
Dams and water supplies Major refurbishment
Reconstruction or major upgrade
Sewers Reconstruction or major upgrade 50
Waste management Upgrade
Major refurbishment


The information gathered for this assessment points to five key areas of climate sensitivity in Ontario: critical infrastructure, water quality and supply, human health and well-being, remote and resource-based communities, and unmanaged and managed ecosystems. The degree to which these systems are vulnerable to future climate change will depend on the success of adaptation actions, which will, in turn, require enhancement and application of existing adaptive capacity.

Critical infrastructure, as used in this analysis, includes water treatment and distribution systems, energy generation and transmission systems, and transportation. Disruptions to all of these have occurred in all subregions of the province in recent years, and are expected to occur more frequently during the present century. In recent years, flooding associated with severe weather has disrupted transportation and communication lines, with damage costs exceeding $500 million. Lengthy and extensive power outages have resulted from the failure of transmission grids and distribution lines. Warmer winters have resulted in a shorter winter road season, limiting access to remote communities and natural resources. Lower water levels in the Great lakes have increased shipping costs in some seasons, and reduced hydroelectricity output. Climate change is expected to result in even lower water levels that would further compromise Great Lakes shipping and potentially reduce hydroelectricity output by more than 1100 MW by 2050.

Since infrastructure must be resilient under both current and future climate conditions, climate change needs to be factored into design. Nonetheless, understanding of the impacts of climate change on infrastructure remains limited, and would benefit from further research to refine projections of regional impacts and climate parameters that are critical for infrastructure design, such as maximum wind speeds, snow loads and precipitation intensities (Auld and MacIver, 2005). In the south subregion, infrastructure is aging, thus increasing the proportion of infrastructure that is vulnerable to climate extremes (Auld and MacIver, 2005). Investment in water and wastewater infrastructure alone over the next 15 years in Ontario is expected to range from $30 to $40 billion, with $25 billion to be spent on capital renewal and the remainder on deferred maintenance and growth (Ontario Ministry of Public Infrastructure Renewal, 2005). As demonstrated by the 1998 ice storm, the 2003 blackout and Toronto's 2005 flood, all components of critical infrastructure are interconnected, as much of Ontario's economy, industry and urban communities depend on ‘just-in-time delivery' and uninterrupted service (Auld et al., 2005).

Water shortages, already documented in the south subregion of the province, are projected to become more frequent as summer temperatures and evaporation rates increase. Sections of Durham County, Waterloo and Wellington Counties, and the shoreline of southern Georgian Bay, where growth strategies indicate that population will continue to increase significantly, will become more vulnerable to shortages within the next 20 years. Current legislation provides the framework to deal with both gradual changes in average conditions and changes in the frequency and magnitude of drought. The Clean Water Act requires that source protection planning be an ongoing, long-term undertaking, as the many climatic and non-climatic factors influencing water resources will be changing. As a result, climate change can be mainstreamed in subsequent plans as data gaps are closed, skills are developed and experience is gained (Box 5; de Lo ë and Berg, 2006). The Ontario Low Water Response similarly provides a strategy to ensure provincial preparedness to respond to extreme drought conditions, and provides an existing structure to deal with more frequent droughts as they occur.


Mainstreaming adaptation

"Source protection planning under the Clean Water Act has created an outstanding opportunity to mainstream climate change. The focus in source protection planning is necessarily on threats to drinking water safety. However, under the Clean Water Act these threats are characterized broadly to include both those that pertain to water quality and water quantity. The Act also requires unprecedented attention to concerns such as the relationship between land and water, and between water uses and water supplies. Climate change must be a central consideration when these relationships are explored through watershed characterizations and water budgets. "
(de Loë and Berg, 2006)

The health risks to Ontario residents as a result of changing climate include illness, injury and premature death related to extreme weather, heat waves and smog episodes, as well as gradual changes in ecological conditions that facilitate the spread of vector- and rodent-borne diseases. Approximately 6000 Ontario residents die prematurely each year due to air pollution, and heat waves may be a contributing factor in about 20% of these deaths in cities in the south subregion. Smog alert advisory systems are commonplace in the south subregion of Ontario (and some cities in the central subregion), and some southern cities have recently introduced heat-health alert systems. Heat-related mortality could more than double in these cities by the 2050s, while air pollution mortality could increase about 15 to 25% over the same interval. The types of extreme weather that contributed to the E. coli outbreak in Walkerton, Ontario, which killed 7 and caused 2300 illnesses, are projected to increase. Changes in climate are also expected to enhance the northerly expansion of Lyme disease, and hantavirus pulmonary syndrome could emerge as a health risk.

Remote and resource-based communities are particularly sensitive to climate variability and change. Recent drought, ice-jam flooding, increases in forest fires, warmer winters and the absence of late spring frost have presented challenges for forestry operations and restricted access to communities and resources. Projected increases in winter temperatures will further reduce the viable operating season of winter roads, limiting access for the delivery of bulk construction materials, food and fuel to many far northern communities. Increased frequency of forest fires and pest outbreaks will adversely impact the health and economic base of communities dependent on the forest industry, particularly in Ontario's boreal forest. Communities looking to diversify their economies by developing winter tourism activities should do so with caution, with snowmobiling, cross-country skiing and ice fishing all being vulnerable to projected climate change in the middle to long term.

During the next 30 years, the vulnerability of many resource-dependent Ontario communities may increase as the average age of residents increases, population declines and youth leave the communities to seek employment elsewhere (Ontario Ministry of Finance, 2006). The cumulative impacts of changes in climate and other factors will have ramifications for the health status of residents in these communities and implications for the level of social services required.

Ontario's ecosystems are currently stressed by the combined influence of climate, human activities, movement of indigenous and non-indigenous species, and such natural disturbances as fire and outbreaks of insects and disease. Wetlands are particularly sensitive to changes in climate and other factors, and have experienced dramatic declines in recent years, especially in the south subregion of Ontario. Warmer winters, longer summers and associated changes in the mean average temperature have led to lower Great Lakes water levels, warmer water temperatures and reduced available soil moisture in forests and on agricultural land. Examples of impacts already occurring include observed changes in fish dominance from cold- and cool-water species to warm-water species in the south subregion; changes in the compositions of aquatic and terrestrial ecosystems in the north subregion; and reduced numbers and health of polar bears and seals . Further reductions in Great Lakes water levels as a result of climate change will further compromise wetlands that presently maintain shoreline integrity, reduce erosion, filter contaminants, absorb excess storm water, and provide important habitat for fish and wildlife. The number and populations of invasive species in the Great Lakes are likely to increase.

As climate change impacts all species and all ecosystems, agencies and organizations responsible for natural asset management will be required to address a plethora of emerging issues in the twenty-first century. For example, climate-induced changes to habitats and the distribution and abundance of plants and animals will alter the character of many parks and protected areas established and managed in support of biodiversity conservation efforts, necessitating fundamental changes to existing management strategies (Lemieux et al., 2007).


Adapting to climate change will involve making decisions aimed at reducing vulnerability to experienced and anticipated impacts, as well as taking advantage of new opportunities. These decisions will be made in the context of the myriad of non-climatic factors influencing environmental, economic and social systems. Vulnerability to climate (current and future) is influenced by a range of social, economic, political and cultural factors that, like climate, are not static but change over time. Reducing vulnerability to current risks and enhancing the capacity of systems to adapt to changing conditions are effective adaptation goals in light of the uncertainties inherent in climate change projections. Communities can improve their ability to respond to changing conditions by educating their members, protecting the most vulnerable, developing and implementing adequate adaptation measures, and building social resilience (Crabb é and Robin, 2006).

Adaptive capacity is defined as the “potential, capability or ability of a system to adapt to climate change stimuli or their effects or impacts ” (Smit et al., 2001, p. 894; see Chapter 2). An initial characterization of some basic determinants of adaptive capacity in each of the subregions of Ontario is presented in Table 7. This listing is based on basic statistics, available literature (not limited to climate change) and the judgment of the chapter authors. It is not the product of extensive analysis, but rather is intended to stimulate future analyses of adaptive capacity. The table suggests that all subregions have strengths and weaknesses with respect to adaptive capacity, and further understanding of these may assist in deciding what constitute the most appropriate adaptation measures in each region.

The limited research available on adaptive capacity in Ontario with specific reference to climate change deals largely with institutions. Institutional capacity depends on appropriately perceived risk and the ability to intervene in a timely and anticipatory fashion. Perceptions of the risks associated with experienced or anticipated impacts of climate change are strongly influenced by local experience of extreme events and severe impacts, such as ice storms, floods and well contamination. Institutions can both facilitate, and create barriers to, adaptation.

The strengths that have been identified with regard to institutions in Ontario include the high level of expertise for storm water management within conservation authorities; access to available technological options; municipal access to reciprocal insurance; and the persistence, sustainability and resilience of institutions and social arrangements. Increased flexibility and autonomy of municipalities to facilitate appropriate reaction to local economic, environmental and social issues, as outlined as one of the objectives of the Municipal Act 2001, also increase the adaptive capacity of local decision-makers (Crabb é and Robin, 2006). Identified weaknesses include overlapping jurisdictions and blurred areas of responsibility; requirement for agreements between municipalities to manage resources that cross jurisdictional boundaries; reliance on voluntary implementation of some key activities; institution restructuring; constrained financial and expert resources, particularly in rural areas; uneven distribution of resources; and the lack of expertise regarding the impact of climate change on built infrastructure and available adaptation technology (Ivey et al., 2004; Crabbé and Robin, 2006).

Effective adaptation is also dependent on decision-makers being well informed and having a solid understanding of climate change risks. A recent survey conducted within the Forests Division and the Science and Information Resources Division of the Ontario Ministry of Natural Resources, for example, indicated that, while a large majority of respondents believed that climate change would affect forests in the next 50 years and about half of respondents believed the impacts would be significant for forest communities, nearly all strongly believed that neither forest policymakers nor the public understood how climate change would affect forest communities (Colombo, 2006). Despite these concerns, the importance of taking actions that enhance efforts to understand and adapt to climate change is highlighted in the Ministry's Strategic Directions report for 2005 (Ontario Ministry of Natural Resources, 2005b).


Broad characteristics of adaptive capacity within sub regions of Ontario1.
Determinant Subregion
North Central South
Economic Resources Highly dependent on climate-sensitive natural resources

Significant non-market economy
Highly dependent on climate-sensitive natural resources

Increasing diversification
Highly diversified

Limited climate sensitivity
Technology Access somewhat constrained by economic resources High access to technology

Key aspect of economy in some areas

Limited knowledge of relevance of technology to address climate sensitivity
High access to technology

Key aspect of economy
Limited knowledge of relevance of technology to address climate sensitivity
Information and Skills Strong traditional and local knowledge of climate sensitivities and adapting to change

Smaller percentage of workforce with technical training
Significant proportion of workforce with technical training

Good understanding of climate sensitivities in resource-based industries
Significant proportion of workforce with technical training

Limited knowledge of climate sensitivities
Infrastructure Limited infrastructure
Maintenance and expertise issues

Ground access to many communities limited to seasonal roads

Permafrost sensitivity problematic
Well-developed in urban areas

Concerns about renewal
Lack of expertise regarding climate change impacts on built environment
Highly developed
Much of infrastructure is aging

Lack of expertise regarding climate change impacts on built environment

High dependence on potentially vulnerable electricity grid
Institutions Limited access

Strong social cohesion
Well developed

Overlapping jurisdictions can hinder decision-making ability
Highly developed

Overlapping jurisdictions can hinder decision-making ability
Equity2 Broad disadvantages for aboriginal populations, rural communities, and the urban poor.
Municipalities have access to reciprocal insurance and disaster relief

1 Based on judgement of chapter lead authors, and intended to stimulate future analyses of vulnerability.
2 Most appropriate to examine at regional / provincial scale.


Given its strong and diversified economic base and abundant natural resources, Ontario as a whole is well placed to manage adaptation to changing climate conditions. Opportunities exist for rapidly mainstreaming adaptation to climate change into decision-making through, for example, the Clean Water Act, and other policies or programs that deal with, among other things, infrastructure and renewal, low water programs and growth strategies.

A number of knowledge gaps have emerged from this assessment, including limited understanding of cumulative impacts and the implications of climate change for specific regions, sectors and segments of the population. Particularly notable are the knowledge gaps for the central and north subregions, adaptation options, and understanding adaptive capacity in all subregions. Many potential adaptive actions and measures to address climate change impacts exist for all sectors, systems and subregions, but there is wide variation in the documentation of what these actions/measures are, whether they are currently in place or being developed, and whether they are likely to be effective at the local or community level. The ‘tool kit' of adaptation measures can be extensive but, with a few exceptions (e.g. Edwards et al., 1999; Bruce et al., 2006), there is limited knowledge regarding how these could be applied in most settings.

As a result, understanding of the vulnerability of natural and human systems to climate change is also limited, particularly in the context of multiple stressors such as human activities, economic growth and invasive species. Vulnerability usually only becomes truly evident when conditions comparable to those projected for the future as a result of climate change, interact with a sensitive population. This chapter, therefore, has drawn heavily on lessons learned as a result of recent extreme climate events. In the case of heat stress, for example, experience in the City of Toronto clearly indicates that vulnerability among a sensitive population is shaped by the effectiveness of existing warning systems and the social determinants of health that either exacerbate or reduce risk exposure.

The resilience of communities, regions and sectors to address the risks and opportunities presented by climate change may be enhanced by development and implementation of adaptation plans or strategies, such as has been recommended for First Nation communities and health infrastructure (Chiotti et al., 2002; Resource Futures International, 2004). Elements likely to be common to such plans or strategies include the following:

  • Stakeholder engagement: This is critical in identifying research priorities, assessing the effectiveness of current adaptation actions to future conditions, and determining the most appropriate response actions.
  • Monitoring and surveillance: Data related to climate, ecosystem function, social conditions and economic impacts, including those derived from community-based monitoring, are needed to inform effective adaptation decision-making.
  • Education: Increased awareness of the social, economic and environmental impacts of climate change at local to regional scales will help facilitate development of adaptation measures.
  • Partnership building: Effective adaptation measures will require co-operation and co-ordination between all orders of government, industry, communities, universities and colleges, voluntary organizations, public interest groups and individuals.