Kyoto Protocol greenhouse gases and the Canadian Environmental Protection Act: annex B


Annex B: Supporting Evidence for Sections 3.1 to 3.4 of this Report

Table 1: Current impacts on natural systems

"From the collective evidence, there is high confidence that recent regional climate changes in temperature have had discernible impacts on many physical and biological systems." (WGII SPM Section 2.1 pg.223 SynRpt)

"Observational evidence indicates that climate changes in the 20th century already have affected a diverse set of physical and biological systems. Examples of observed changes with linkages to climate include shrinkage of glaciers; thawing of permafrost; shifts in ice freeze and break-up dates on rivers and lakes; increases in rainfall and rainfall intensity in most mid- and high latitudes of the Northern Hemisphere; lengthening of growing seasons; and earlier flowering dates of trees, emergence of insects, and egg- laying in birds. Statistically significant associations between changes in regional climate and observed changes in physical and biological systems have been documented in freshwater, terrestrial, and marine environments on all continents."] [WGII TechSumm 7.1 pg. 282 SynRpt.]

"The presence of multiple causal factors (e.g. land use change, pollution) makes attribution of many observed impacts to regional climate change a complex challenge. Nevertheless, studies of systems subjected to significant regional climate change - and with known sensitivities to that change - find changes that are consistent with well- established relationships between climate and physical or biological processes (e.g. shifts in the energy balance of glaciers, shifts in the ranges of animals and plants when temperatures exceed physiological thresholds) in about 80% of biological cases and about 99% of physical cases." [WGII TechSumm 7.1 p. 282 SynRpt.]

"Based on observed changes, there is high confidence that 20th century climate changes have had a discernible impact on many physical and biological systems. Changes in biota and physical systems observed in the 20th century indicate that these systems are sensitive to climatic changes that are small relative to changes that have been projected for the 21st century. High sensitivity of biological systems to long-term climatic change also is demonstrated by paleorecords." [WGII TechSumm 7.1 p. 282 SynRpt.]

"...there is high confidence that observations of widespread accelerated glacier retreat and shifts in the timing of streamflow from spring toward winter in many areas are associated with observed increases in temperature."[WGII TechSumm 4.1]

Table 2: Future impacts on natural systems

"Diversity in ecological systems is expected to be affected by climate change and sea level rise, with an increased risk of extinction of some vulnerable species (high confidence)." (Synthesis Report Result 3.18 p. 68)

"Without adaptation, some species that currently are classified as "critically endangered" will become extinct, and the majority of those labeled "endangered or vulnerable" will become much rarer in the 21st century (high confidence)" [WGII TechSumm 4.3]

"Small increases in global average temperature may cause significant and irreversible damage to some systems and species, including possible local, regional, or global loss. Some plant and animal species, natural systems, and human settlements are highly sensitive to climate and are likely to be adversely affected by climate changes associated with scenarios of <1ºC mean global warming. Adverse impacts to species and systems would become more numerous and more serious for climatic changes that would accompany a global mean warming of 1-2ºC and are highly likely to become even more numerous and serious at higher temperatures. The greater the rate and magnitude of temperature and other climatic changes, the greater the likelihood that critical thresholds of systems would be surpassed" (WGII TechSumm 7.2.1)

"Species that may be threatened with local or global extinction by changes in climate that may accompany a small mean global temperature increase include critically endangered species generally, species with small ranges and low population densities, species with restricted habitat requirements, and species for which suitable habitat is patchy in distribution, particularly if under pressure from human land-use and land-cover change." [WGII TechSumm 7.2.1 p. 285]

"Natural systems that may be threatened include coral reefs, mangroves, and other coastal wetlands; montane ecosystems that are restricted to the upper 200-300 m of mountainous areas; prairie wetlands; remnant native grasslands; coldwater and some coolwater fish habitat; ecosystems overlying permafrost; and ice edge ecosystems that provide habitat for polar bears and penguins." [WGII TechSumm 7.2.1 p. 285]

"Climate change will lead to poleward movement of the southern and northern boundaries of fish distributions, loss of habitat for cold- and coolwater fish, and gain in habitat for warmwater fish (high confidence). As a class of ecosystems, inland waters are vulnerable to climatic change and other pressures owing to their small size and position downstream from many human activities (high confidence). The most vulnerable elements include reduction and loss of lake and river ice (very high confidence), loss of habitat for coldwater fish (very high confidence), increases in extinctions and invasions of exotics (high confidence), and potential exacerbation of existing pollution problems such as eutrophication, toxics, acid rain, and UV-B radiation (medium confidence)." [WGII Tech Summ 4.3]

"Vegetation distribution models since the SAR (Second Assessment Report) suggest that mass ecosystem or biome movement is most unlikely to occur because of different climatic tolerance of the species involved, different migration abilities, and the effects of invading species. Species composition and dominance will change, resulting in ecosystem types that may be quite different from those we see today. These changes will lag the changes in climate by years to decades to centuries (high confidence).... Recent modeling studies continue to show potential for significant disruption of ecosystems under climate change (high confidence)." [WGII TechSumm 4.3]

"Climate change in the polar region is expected to be among the greatest of any region on Earth. Twentieth century data for the Arctic show a warming trend of as much as 5°C over extensive land areas (very high confidence), while precipitation has increased (low confidence). There are some areas of cooling in eastern Canada. The extent of sea ice has decreased by 2.9% per decade, and it has thinned over the 1978-1996 period (high confidence). There has been a statistically significant decrease in spring snow extent over Eurasia since 1915 (high confidence). The area underlain by permafrost has been reduced and has warmed (very high confidence). The layer of seasonally thawed ground above permafrost has thickened in some areas, and new areas of extensive permafrost thawing have developed." [WGII TechSumm 5.7 p. 276 SynRpt]

"Permafrost currently underlies 24.5% of the exposed land area of the Northern Hemisphere. Under climate warming, much of this terrain would be vulnerable to subsidence, particularly in areas of relatively warm, discontinuous permafrost. The area of the Northern Hemisphere occupied by permafrost could eventually be reduced by 12 to 22% of its current extent and could eventually disappear from half of the present-day Canadian permafrost region" [SynRpt 4.16. p. 84.]

"Some wetlands will be replaced by forests or heathlands, and those overlying permafrost are likely to be disrupted as a result of thawing of permafrost (high confidence). Most wetland processes are dependent on catchment-level hydrology; thus, adaptations for projected climate change may be practically impossible. Arctic and subarctic ombrotrophic bog communities on permafrost, as well as more southern depressional wetlands with small catchment areas, are likely to be most vulnerable to climate change". [WGII TechSumm 4.3]

"Peak streamflow will move from spring to winter in many areas where snowfall currently is an important component of the water balance (high confidence). .....Glacier retreat will continue, and many small glaciers may disappear (high confidence). The rate of retreat will depend on the rate of temperature rise.....[WGII TechSumm 4.1].

"Climate change is expected to increase the areal extent and productivity of forests over the next 50-100 years (medium confidence). However, climate change is likely to cause changes in the nature and extent of several "disturbance factors" (e.g., fire, insect outbreaks) (medium confidence)." [WGII TechSumm 5.6.5]

Table 3a: Impacts on water resources and food production

Water Shortages:

"Projected climate change would exacerbate water shortage and quality problems in many water-scarce areas of the world, but alleviate it in some other areas. ...Climate change is projected to reduce streamflow and groundwater recharge in many parts of the world but to increase it in some other areas (medium confidence)....Several hundred million to a few billion people are projected to suffer a supply reduction of 10% or more by the year 2050 for climate change projections corresponding to 1% per year increase in CO2 emissions." [SynRpt 3.22 p. 72]

"Approximately 1.7 billion people, one-third of the world's population, presently live in countries that are water-stressed (i.e., using more than 20% of their renewable water supply--a commonly used indicator of water stress). This number is projected to increase to about 5 billion by 2025, depending on the rate of population growth." [WGII TechSumm 4.1]

"Retreat of mountain glaciers already has begun in North America and in other regions of the world.....On a regional scale, the retreat of glaciers will affect water resources by changing (probably decreasing) water supply from glacial melt during the summer or changing the spatial location of the melt source....." WGII Report 15.2.2.2.1.

Food Production:

"By the 2080s, the additional number of people at risk of hunger as a result of climate change is estimated to be about 80 million." [WGII Report 5.3.6.2 p. 270].

The risk of hunger is not apportioned equitably within populations but will fall disproportionately on the urban poor, displaced people, rural smallholder producers, among others.[WGII Report 5.3.6.2 p. 270]

"Degradation of soil and water resources is one of the major future challenges for global agriculture. It is established with high confidence that those processes are likely to be intensified by adverse changes in temperature and precipitation."[WGII TechSumm 4.2]

"Models of cereal crops indicate that in some temperate areas potential yields increase for small increases in temperature but decrease with larger temperature changes (medium to low confidence). In most tropical and subtropical regions potential yields are projected to decrease for most projected increases in temperature (medium confidence)."[SynRpt 3.21 p. 71]

"Some crops would benefit from modest warming accompanied by increasing CO2 but effects would vary among crops and regions (high confidence), including declines due to drought in some areas of Canada's Prairies and the U.S. Great Plains, potential increased food production in areas of Canada north of current production areas, and increased warm-temperature mixed forest production (medium confidence). However, benefits for crops would decline at an increasing rate and possibly become a net loss with further warming (medium confidence). [WGII SPM Table SPM-2 P. 235 Syn Rpt]

Table 3b: Impacts arising from changes in extreme events, sea level rise and abrupt changes

Extreme Events:

"The frequency and magnitude of many extreme climate events increase even with a small temperature increase and will become greater at higher temperatures (high confidence). Extreme events include, for example, floods, soil moisture deficits, tropical cyclones, storms, high temperatures, and fires. The impacts of extreme events often are large locally and could strongly affect specific sectors and regions. Increases in extreme events can cause critical design or natural thresholds to be exceeded, beyond which the magnitude of impacts increases rapidly (high confidence)." [WGII Tech Summ 7.2.4] ....

"The duration, location, frequency and intensity of extreme weather and climate events are likely, to very likely, to change, and would result in mostly adverse impacts on biophysical systems." [SynRpt 4.3 p. 80]

"More hot days and heat waves and fewer cold days and frost days are very likely over nearly all land areas. The changes in temperature extremes are likely to result in increased crop and livestock losses..... and increased human morbidity and heat stress-related mortality". [SynRpt 4.5 p. 80]

"Increased incidence of death and serious illness in older age groups and urban poor; increased heat stress in livestock and wildlife; increased risk of damage to a number of crops (all high confidence of occurrence in some areas)" [SynRpt Table 4-1 p. 82]

"The amplitude and frequency of extreme precipitation events is very likely to increase over many areas and the return periods for extreme precipitation events are expected to decrease. This would lead to more frequent floods and landslides with attendant loss of life, health impacts (e.g. epidemics, infectious diseases, food poisoning), property damage, loss to infrastructure and settlements... amongst others." [SynRpt 4.6 p. 80]

"Increased flood, landslide, avalanche and mudslide damage; increased soil erosion (all high confidence of occurrence in some areas)." [SynRpt Table 4-1 p. 82]

"Increased summer drying over most mid-latitude continental interiors and associated risk of drought (likely)...(projected impacts include)...."decreased crop yields; decreased water resource quantity and quality; increased risk of forest fire (all high confidence of occurrence in some areas)" [SynRpt Table 4-1. p. 82]

"Flood magnitude and frequency are likely to increase in most regions, and low flows are likely to decrease in many regions. .... The general increase in flood magnitude and frequency is a consequence of a projected general increase in the frequency of heavy precipitation events, although the effect of a given change in precipitation depends on catchment characteristics. Changes in low flows are a function of changes in precipitation and evaporation. Evaporation generally is projected to increase, which may lead to lower low flows even where precipitation increases or shows little change." [WGII TechSumm 4.1]

Sea Level Rise:

"Many coastal areas already are experiencing increased levels of sea flooding, accelerated coastal erosion, and seawater intrusion into freshwater sources; these processes will be exacerbated by climate change and sea-level rise. Sea-level rise in particular has contributed to erosion of sandy and gravel beaches and barriers; loss of coastal dunes and wetlands; and drainage problems in many low-lying, mid-latitude coastal areas. Highly diverse and productive coastal ecosystems, coastal settlements, and island states will continue to be exposed to pressures whose impacts are expected to be largely negative and potentially disastrous in some instances." [WGII TechSumm 4.4]

"Few studies have examined potential changes in prevailing ocean wave heights and directions and storm waves and surges as a consequence of climate change. Such changes can be expected to have serious impacts on natural and human-modified coasts because they will be superimposed on a higher sea level than at present." [WGII TechSumm 4.4]

"Tens of millions of people live in the settlements potentially flooded. For example, estimates of the mean annual number of people who would be flooded by coastal storm surges increase several-fold (by 75 million to 200 million people, depending on adaptive responses) for mid-range scenarios of a 40-cm sea-level rise by the 2080s relative to scenarios with no sea-level rise." [WGII Tech Summ 4.5]

"Populations that inhabit small islands and/or low-lying coastal areas are at particular risk of severe social and economic effects from sea-level rise and storm surges. Many human settlements will face increased risk of coastal flooding and erosion, and tens of millions of people living in deltas, in low-lying coastal areas, and on small islands will face risk of displacement. Resources critical to island and coastal populations such as beaches, freshwater, fisheries, coral reefs and atolls, and wildlife habitat would also be at risk." [SPM SynRpt p. 12]

"Projected sea-level rise will increase the average annual number of people flooded in coastal storm surges (high confidence)......Significant portions of many highly populated coastal cities are also vulnerable to permanent land submergence and especially to more frequent coastal flooding superimposed on surge heights, due to sea-level rise. These estimates assume no change in the frequency or intensity of storms, which could exacerbate the effects of sea-level rise on flooding risk in some areas." [SynRpt 3.24 p. 74]

"Low-latitude tropical and subtropical coastlines, particularly in areas where there is significant human population pressure, are highly susceptible to climate change impacts. These impacts will exacerbate many present-day problems.....For instance, human activities have increased land subsidence in many deltaic regions by increasing subsurface water withdrawals, draining wetland soils, and reducing or cutting off riverine sediment loads. Problems of inundation, salinization of potable groundwater, and coastal erosion will all be accelerated with global sea-level rise superimposed on local submergence. Especially at risk are large delta regions of Asia and small islands whose vulnerability was recognized more than a decade ago and continues to increase." [WGII TechSumm 4.4]

"High-latitude (polar) coastlines also are susceptible to climate warming impacts, although these impacts have been less studied. Except on rock-dominated or rapidly emerging coasts, a combination of accelerated sea-level rise, more energetic wave climate with reduced sea-ice cover, and increased ground temperatures that promote thaw of permafrost and ground ice (with consequent volume loss in coastal landforms) will have severe impacts on settlements and infrastructure and will result in rapid coastal retreat." [WGII TechSumm 4.4]

"Sea-level rise would result in enhanced coastal erosion, coastal flooding, loss of coastal wetlands, and increased risk from storm surges (in North America), particularly in Florida and much of the U.S. Atlantic coast (high confidence)." [WGII SPM Table SPM-2 p. 235 SynRpt]

Abrupt climatic and ecological changes:

"Greenhouse gas forcing in the 21st century could set in motion large-scale, high impact, non-linear, and potentially abrupt changes in physical and biological systems over the coming decades to millennia, with a wide range of associated likelihoods." [IPCC SynRpt 4.9 p. 81]

"Human-induced climate change has the potential to trigger large-scale changes in Earth systems that could have severe consequences at regional or global scales. The probabilities of triggering such events are poorly understood but should not be ignored, given the severity of their consequences. Events of this type that might be triggered include complete or partial shutdown of the North Atlantic and Antarctic Deep Water formation, disintegration of the West Antarctic and Greenland Ice Sheets, and major perturbations of biosphere-regulated carbon dynamics. .... Large temperature increases have the potential to lead to large-scale discontinuities in the climate system (medium confidence)." [WGII TechSumm 7.2.5]

"The likelihood of many of these changes in Earth systems is not well-known, but it is probably very low; however, their likelihood is expected to increase with the rate, magnitude and duration of climate change....If these changes in Earth Systems were to occur, their impacts would be widespread and sustained." [WGII SPM p. 225 SynRpt]

"Many natural and managed ecosystems may change abruptly or non-linearly during the 21st century. The greater the magnitude and rate of change, the greater the risk of adverse impacts." [SynRpt 4.17 p. 84]

"Changes in climate could increase the risk of abrupt and non-linear changes in many ecosystems, which would affect their biodiversity, productivity and function." [SynRpt 4.18 p. 84-5]

"In the Antarctic, projected climate change will generate impacts that will be realized slowly (high confidence). Because the impacts will occur over a long period, however, they will continue long after GHG emissions have stabilized. For example, there will be slow but steady impacts on ice sheets and circulation patterns of the global ocean, which will be irreversible for many centuries into the future and will cause changes elsewhere in the world, including a rise of sea level. Further substantial loss of ice shelves is expected around the Antarctic Peninsula." [WGII TechSumm 5.7]

"The Arctic is extremely vulnerable to climate change.....In developed areas of the Arctic and where the permafrost is ice-rich, special attention will be required to mitigate the detrimental impacts of thawing, such as severe damage to buildings and transport infrastructure (very high confidence)" [WGII TechSumm 5.7]

Table 4: Impacts on human life

"If heat waves increase in frequency and intensity, the risk of death and serious illness would increase, principally in older age groups and the urban poor (high confidence). The effects of an increase in heat waves often would be exacerbated by increased humidity and urban air pollution. The greatest increases in thermal stress are forecast for mid- to high-latitude (temperate) cities, especially in populations with non-adapted architecture and limited air conditioning" [WGII TechSumm 4.7]

"More hot days and heat waves are very likely over nearly all land areas." [WG1 Report TechSumm F.5 p.208 SynRpt.]

(In North America) "increased frequency and severity of heat waves may lead to an increase in illness and death, particularly among young, elderly and frail people, especially in large urban areas. Acclimatization may be slower than the rate of ambient temperature change."[WGII Report: CH. 15 (North America) Executive Summary p.738]

"Higher temperatures, changes in precipitation, and changes in climate variability would alter the geographic ranges and seasonality of transmission of vector-borne infectious diseases-- extending the range and season for some infectious diseases and contracting them for others." [WGII TechSumm. 4.7].

"Expansion of areas of potential transmission of malaria and dengue (is projected with) medium to high confidence." [Table 3-1 Section 3.17 IPCC Synthesis Report.]

"Vector-borne diseases, including malaria and dengue fever, may expand their ranges in the United States and may develop in Canada. Tick-borne Lyme disease may also expand its range in Canada.....Diseases associated with water may increase with warming of air and water temperatures, combined with heavy runoff events from agricultural and urban surfaces." [WGII Report: CH. 15 (N.A.) Executive Summary p.738; also WGII TechSumm 5.6.6] [15.2.4]

"Climate change will decrease air quality in urban areas with air pollution problems (medium confidence). An increase in temperature (and, in some models, ultraviolet radiation) increases the formation of ground-level ozone, a pollutant with well- established adverse effects on respiratory health." [WGII TechSumm 4.7]

(In North America) "respiratory disorders may be exacerbated by warming-induced increases in the frequency of smog (ground-level ozone) events, acidic deposition, and particulate air pollution." [WGII Report: CH. 15 (North America.) Executive Summary p.738]

"Any increases in the frequency and intensity of extreme events such as storms, floods, droughts, and cyclones would adversely impact human health through a variety of pathways. These natural hazards can cause direct loss of life and injury and can affect health indirectly through loss of shelter, population displacement, contamination of water supplies, loss of food production (leading to hunger and malnutrition), increased risk of infectious disease epidemics (including diarrhoeal and respiratory disease), and damage to infrastructure for provision of health services (very high confidence)" [WGII TechSumm 4.7]

"The frequency of extreme precipitation events is projected to increase almost everywhere. There is projected to be a general drying of the mid-continental areas during summer." [WG1 TechSumm F.5 p. 208 SynRpt.]

"The Arctic is extremely vulnerable to climate change, and major physical, ecological, and economic impacts are expected to appear rapidly. .... There will be different species compositions on land and sea, poleward shifts in species assemblages, and severe disruptions for communities of people who lead traditional lifestyles. For indigenous communities who follow traditional lifestyles, opportunities for adaptation to climate change are limited (very high confidence)" [WGII TechSumm 5.7].

Table 5: Concerns about the risks from climate change rise with temperature (Box 3-2 IPCC Synthesis Report.)

"Unique and threatened systems: Some changes in species and systems have already been associated with observed changes in climate, and some highly vulnerable species and systems may be at risk of damage or even loss for very small changes in climate. Greater warming would intensify the risks to these species and systems, and place additional ones at risk. "

"Extreme climate events: Increased frequencies and intensities of some extreme events have already been observed and are likely to increase with further warming, as would the risks to human life, property, crops, livestock, and ecosystems. These risks increase where development is occurring in inherently dynamic and unstable zones (e.g., river floodplains and low-lying coastal regions)."

"Uneven distribution of impacts: In general, developing countries are at greater risk of adverse impacts from climate change than are developed countries, of which some of the latter may experience market sector benefits for warming less than a few °C. For greater warming, most regions are at risk of predominantly negative effects from climate change. But developing countries generally would continue to be more severely impacted than developed countries. Within countries, vulnerability varies and the poorest populations often have higher exposure to impacts that threaten their lives and livelihoods. "

"Global aggregate impacts: Globally aggregated market sector impacts may be positive or negative up to a few °C, though the majority of people may be negatively affected. With greater warming, the risk of negative global market sector impacts increases, and impacts would be predominantly negative for most people. "

"Large-scale, high-impact events: The probability of large-scale, high-impact events within a 100- year time horizon such as shutdown of the thermohaline circulation or collapse of the West Antarctic ice sheet is very low for warming less than a few °C. The risk, which is a product of the probabilities of these events and the magnitude of their consequences, is largely unquantified. For greater warming, and over a time horizon longer than 100 years, the probabilities and the risks increase, but by an amount that cannot now be estimated."

Figure 1 Annex B: Figure SPM-2 IPCC WGII Summary for Policymakers.

Figure 1 Annex B: Figure SPM-2 IPCC WGII Summary for Policymakers.

Figure SPM-2: Reasons for concern about projected climate change impacts. The risks of adverse impacts from climate change increase with the magnitude of climate change. The left part of the figure displays the observed temperature increase relative to 1990 and the range of projected temperature increase after 1990 as estimated by Working Group I of the IPCC for scenarios from the Special Report on Emissions Scenarios. (Inserted Note: The coloured lines represent average projections of global temperature from several climate models that result from different scenarios of future GHG and aerosol emissions. The grey shadowy area encompasses the full range of projections from the models.) The right panel displays conceptualizations of five reasons for concern regarding climate change risks evolving through 2100. White indicates neutral or small negative or positive impacts or risks, yellow indicates negative impacts for some systems or low risks, and red means negative impacts or risks that are more widespread and/or greater in magnitude. The assessment of impacts or risks takes into account only the magnitude of change and not the rate of change. Global mean annual temperature change is used in the figure as a proxy for the magnitude of climate change, but projected impacts will be a function of, among other factors, the magnitude and rate of global and regional changes in mean climate, climate variability and extreme climate phenomena, social and economic conditions, and adaptation.

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