ClimateChange Assessment Guide.pdf - University of Waterloo

Introduction1. Introduction1“Climate change impact, adaptation and vulnerability(CCIAV) assessment has now moved far beyond its earlystatus as a speculative, academic endeavour… This ispropelling CCIAV assessment from being an exclusivelyresearch-oriented activity towards analytical frameworksthat are designed for practical decision making” (Carteret al., 2007 161).Climate change, as evidenced by warming and otherrelated effects, is now an unequivocal fact in our time(Intergovernmental Panel on Climate Change (IPCC),2007c). Society needs to respond to climate change ontwo levels: by adapting to the impacts of a changingclimate; and by implementing mitigation actions at theglobal-scale to prevent or slow the degree of climatechange. Currently, natural resource managers areadapting to anticipated change in many disciplinesat the local scale. Water resources are of fundamentalimportance to humans and ecosystems; as such, thisdiscipline is often central to these activities and hasreceived much attention in recent research. Thatresearch has concentrated on improving climate changeimpact assessment methods as well as delineating futurepotential impacts.Quantifying the hydrologic effects of climate change,through climate change impact assessments, are the firststep in mainstreaming climate change in the planningprocess and thus, beginning the adaptation process.Climate change impact assessment procedures haveadvanced to the stage where they can be applied bywater managers and planners across Ontario. Waterresource impact assessments related to climate changecan be integrated into a variety of water managementaspects, including Drinking Water Source Protection,the watershed planning process, Permit To Take Water(PTTW) applications, and subwatershed studies.Projected changes in hydrology need to inform decisionmaking and planning through adaptation strategydevelopment and risk based assessment.This Guide for Assessment of Hydrologic Effects ofClimate Change in Ontario (the Guide) is intended foruse by water resource scientists, engineers and plannersin conducting climate change impact assessments.It outlines a recommended climate change impactassessment procedure for water resource studies inOntario. The procedure is designed for applicationsranging from screening level to complex water resourceassessments. Water resource and climate models aredefAdaptation • adjustment in natural or humansystems in response to actual or expectedclimatic stimuli or their effects, which moderatesharm or exploits beneficial opportunities; thereare various types of adaptation, includinganticipatory, autonomous and plannedadaptation.Mitigation • an anthropogenic intervention toreduce the anthropogenic forcing of the climatesystem; includes strategies to reduce greenhousegas sources and emissions and enhancinggreenhouse gas sinks.Vulnerability • degree to which a systemis susceptible to, and unable to cope with,adverse effects of climate change, includingclimate variability and extremes; function of thecharacter, magnitude, and rate of climate changeand variation to which a system is exposed, itssensitivity, and its adaptive capacity.Impact Assessment • practice of identifying andevaluating, in monetary and/or non-monetaryterms, the effects of climate change on naturaland human systems (Intergovernmental Panel onClimate Change (IPCC), 2007a).central to this discussion. The Guide steps throughdecisions involved in selecting and developing futureclimate change scenarios and the procedures neededto generate time series of climate variables (i.e., airtemperature, precipitation, wind speed, solar radiation,etc.) representing future time horizons (i.e., 2020s, 2050s,2080s) for hydrologic model input. Other independentfactors that must be considered when designing futurescenarios are also addressed. Background informationconcerning global climate change, climate changein Ontario and the influence of climate change onhydrologic processes is provided for context.1.1 Purpose and ObjectivesThe purpose of this Guide is to provide a methodologyfor conducting assessments of the effects of climate