Summary and Conclusion

The influence of weather conditions and climate is vast. Impacts that are generally poorly documented appear gradually and subtly at the pace of changing mean values or variability statistics. Until now, these changes have generally followed global trends anticipated by the Intergovernmental Panel on Climate Change and presented in their assessment reports. The impacts of extreme events are remarkable because of their scale, suddenness and spectacular nature, but it is difficult to tie them directly and exclusively to climate change because they are, by definition, rare events. Globally, the scope of climate change, including some extreme events for which an increase in frequency, intensity and duration is predicted, is expected to have an increasingly significant and perceptible impact on the public, the natural and built environment, and socioeconomic activity. Given the anticipated scope of climate change, natural and human system reaction (adaptation) will be able to adjust and even transform impacts that are sometimes negative, other times positive. Despite the many remaining uncertainties and the complexity of direct and indirect impacts occurring in parallel with other changes that affect vulnerability, the following qualitative observations emerge from this summary:

• For the public, the impact of climate change - particularly indirect impacts through reactions of the natural and built environment - would result in heightened risk to health, security and well-being. The application of adaptation measures, mainly preventive and prioritized for populations now or soon to be at risk, would minimize the scope of negative impacts, including oppressive heat, increased pollution, poorer water quality, exposure to ultraviolet rays, zoonotic diseases and events causing injury and death. These measures include actions to alter risk-creating behaviour, assist vulnerable groups and strive to reduce climatic risk in land-use planning.
• In the natural environment, the lithosphere, hydrosphere, cryosphere and biosphere would experience gradual transformations corresponding to long-term trends, with occasionally more perceptible displays related to changes in the frequency, intensity and duration of extreme or threshold events. Landscapes would, of course, be reshaped under the influence of climate change, as would the hydrology and geomorphology of streams and the distribution and relative abundance of plants and wildlife. Various regional impacts would trigger spontaneous and complex adaptation reactions. Of more serious concern than the northward movement of ecosystems, many threatened species and rare ecosystems would be at risk of disappearing, particularly in areas of intense human activity, but the effects of these changes would be positive or negative depending on the subregion, uses or interests, and according to perceptions. With respect to forest resources, it is difficult to predict the changes that will occur, given that both positive (e.g. CO² level and higher temperatures, longer growing season) and negative impacts (e.g.insects and pathogens, extreme weather events) are anticipated.
• The built environment does not adapt spontaneously. For example, engineering practices that have been based on the assumption that climate has been historically stable should be revised in light of new and changing climate data. Although changes in means can result in accelerated wear or loss of performance of infrastructure, several types of infrastructure are known to be particularly sensitive to increases in the frequency of extreme events. Adaptation strategies applied on a priority basis to critical infrastructure or infrastructure with favourable cost-benefit analyses (costs of adaptation solutions versus life cycle of infrastructure) would make it possible to limit the magnitude of anticipated impacts. In a context of widespread aging of infrastructure contributing to a potential rise of vulnerability in Quebec, it will be crucial to invest in the refurbishment or replacement of infrastructure and in new projects in order to reduce climate risks in a preventive way, rather than react after events with significant direct and indirect impacts.
• Of all the anticipated impacts, those that affect socioeconomic activity remain the most difficult to identify. In fact, they depend on still poorly quantified biophysical impacts and complex reactions, such as market mechanisms, perceptions and technological development. Certain activities would benefit from gradual changes of low amplitude, whereas others would be disadvantaged by more dramatic, unpredicted changes or, also, by an increase in the number of extreme weather events. The economic impacts are starting to be estimated, but social impacts in the medium and long terms are more speculative, if not unknown. Although many economic gains and economic development opportunities worth an estimated several hundred million dollars per year could stem from climate change in Quebec, feared economic losses and risks are much more difficult to estimate and go far beyond uniquely economic consequences. Nevertheless, the socioeconomic capacity of Quebec to adapt to climate change, especially gradual change, is high relative to less robust and less diversified economies. The challenge lies in structuring efforts to identify the challenges and implement sustainable solutions in a complex sociopolitical system. The capacity to manage the change - like the opportunities to be seized - will tend to lessen the magnitude of impacts.
• The north subregion should undergo the most significant climate change in absolute terms. It will contribute to the complexity of the issues the subregion is currently facing, which are associated, among other things, with the high exposure of communities to natural risks, to their dependence on critical infrastructure, their access to resources and their traditional way of life, which is closely related to maintaining the current natural environment. It will therefore be necessary to manage the impacts of permafrost thawing, changes in the snow and ice regime, and the transformation of the biosphere, particularly the increased risks to species that are dependent on sea ice, at the same time as high population growth, the many issues related to development, and major socioeconomic changes. Development opportunities associated with navigation, energy production and the mining sector in warmer winter conditions, and diversification of plant and animal life, are possible. Although efforts are being made to minimize the costs of impacts and adaptation, the issues are associated primarily with security, health and well-being of the vulnerable populations due to their isolation. Climate change should be considered in environmental impact studies pertaining to new development projects.
• The vast, resource-filled central subregion could see its environment transformed and its economic sectors increase their productivity (e.g. hydroelectricity production due to higher annual inflows and forest productivity due to faster growth resulting from warmer climatic conditions). However, this scenario remains uncertain for several reasons, including limited historical observations and inconsistent recent trends, lack of understanding of the phenology of species and regional hydrology, assessment tools under development, higher risk related to poorly understood extreme weather events, uncertainty of climate scenarios and, finally, the impacts on the price of resources on continental markets. In addition, given the limited literature available on this sparsely populated subregion, it is likely that many environmental and social impacts that may be considered undesirable are completely unknown at this time.
• The maritime subregion is strongly exposed to climate vagaries and the hydrosphere. Its communities are coastal and partially isolated, and present a marked socioeconomic vulnerability emphasized over the last decade by the collapse of the fishing and forest industries. Moreover, already-occurring coastal erosion will accelerate, increasing the vulnerability of infrastructure, the built environment, or even tourist attractions. Integrated management, including good planning and sustained and early development, appears to be the best adaptation strategy for limiting impacts. One of the great challenges in the coming decades is, beyond question, impact management and prevention in regions of growing risk.
• The south subregion could profit from greater crop productivity if problems of water availability and climate variability are limited. In addition, one effect of an increase in temperature will be a reduction in annual energy consumption. In contrast, whether in rural or urban areas, the built environment will not be optimized as a function of the anticipated climate. Therefore, this subregion, which is characterized by a growing population and increasing population density, the complex interdependence of infrastructure, a shift of its economy towards the service sector associated with changes in international markets, a changing social fabric and a population that is increasingly desensitized to climate conditions, brings together numerous factors that can generate many complex and sometimes costly impacts, related especially to an increase in the frequency, intensity or duration of extreme weather events. The anticipated changes in the water cycle and impacts on water's many uses would help keep sustainability of the resource and public security from floods on the agenda. Finally, an array of indirect impacts often poorly documented and combining with events not connected to climate change, will affect regional biodiversity and public health, security and well-being, the price of seasonal goods and services, immigration, tourism and recreation. Risks should be reduced by applying solutions as diverse as integrating the idea of adaptation to climate change into legislation, building standards and organizational policies, and making efforts to enhance public awareness of climate change. Although planning that integrates the anticipation of impacts can contribute to adaptation, a variety of information, tools and policies will also make society more resilient to climate change.

Clearly, adaptation solutions add to the efforts made to reduce greenhouse gas emissions in the context of the challenges posed by climate change. For hundreds of years, human systems have tended to react to the impacts of the natural variability of the climate system in such a way as to reduce their exposure to climate and increase their adaptive capacity and resilience. With respect to initiatives designed to address future climate unknowns, Table 7 briefly presents a variety of adaptation strategies that already exist or are under study, applied and applicable both to communities and to socioeconomic activities. The table illustrates that human systems will adapt in different ways to minimize or address adverse impacts, or to optimize development opportunities. The table shows that adaptation involves many actors (individuals, communities, industries, provincial, federal and international authorities), that response time varies in length (short-term decision and long-term planning) and that the strategies target different obstacles to adaptation. These strategies can be grouped into five categories:

• develop and understand refers to information acquisition;
• communicate and increase awareness is related to aspects affecting awareness and behaviour modification
• respond and legislate refers to amendments to laws, regulations and standards;
• apply new or existing technology refers to the use of techniques, products and materials;
• apply and recommend guidelines or ways of doing things gives examples of adjustments to internal practices and policies.

The table therefore gives a brief portrait of what could become more general in future.

The challenges that Quebec must meet, along with all inhabitants of the planet, are immense and coloured with uncertainty. As set out in Chapter 10, there are many requirements for meeting the challenge of climate change. They include 1) more relevant and higher-quality data for understanding; 2) better monitoring and warning systems for preparing; 3) greater interaction between scientists and political and operational players in the field of adaptation to maximize technology transfer; 4) leadership and open-mindedness of all society to identify and prioritize the right problems and know how to question oneself at the right time and in the right way; and 5) growing multidisciplinarity and interdisciplinarity while pursuing research in various specialized climate-science related fields, other biophysical sciences, economics, social sciences and health sciences.

Finally, the perceptions and behaviours, the processes and factors leading to decision-making, and the goals and convictions of individuals and communities appear fundamental to the adaptation of human systems because it is humans who will, in the end, make the right or wrong decisions influencing the future.