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

Annex A: Supporting Evidence for Sections 2.1 and 2.2 of this Report

Table 1: Supporting Evidence for observed climate change and its causes
Reference to IPCC Synthesis Report Supporting Evidence References to TAR provided in IPCC Synthesis Report
2.2 "The Earth's climate system has demonstrably changed on both global and regional scales since the pre-industrial era, with some of these changes attributable to human activities".  
2.3 "Emissions of greenhouse gases and aerosols due to human activities continue to alter the atmosphere in ways that are expected to affect the climate (see Table 2-1)." (Table 2.1 is reproduced in this report as Table 3 of Annex A.)  
2.4 "Concentrations of atmospheric greenhouse gases and their radiative forcings have generally increased over the 20th century as a result of human activities. Almost all greenhouse gases reached their highest recorded levels in the 1990s and continue to increase. From the years 1750 to 2000, the concentration of CO2 increased by 31±4%, and that of CH4 rose by 151±25% ......These rates of increase are unprecedented." WGl TAR Chapters 3 & 4, and SRAGA (Special Report on Aviation and the Global Atmosphere).
2.6 "An increasing body of observations gives a collective picture of a warming world and other changes in the climate system (see Table 2-1)." (Table 2.1 is reproduced in this report as Table 3 of Annex A.)  
2.7 "The global average surface temperature has increased from the 1860s to the year 2000, the period of instrumental record. Over the 20th century this increase was 0.6°C with a very likely confidence range of 0.4-0.8°C. It is very likely that the 1990s was the warmest decade, and 1998 the warmest year, of the instrumental record. Extending the instrumental record with proxy data for the Northern Hemisphere indicates that over the past 1,000 years the 20th century increase in temperature is likely to have been the largest of any century, and the 1990s was likely the warmest decade." WGl TAR SPM & WGl TAR Sections 2.2.2, 2.3.2 and 2.7.2.
2.9 "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities."  
2.10 "The observed warming over the 20th century is unlikely to be entirely natural in origin. The increase in surface temperatures over the last 100 years is very unlikely to be due to internal variability alone. Reconstructions of climate data for the last 1,000 years also indicate that this 20th century warming was unusual and unlikely to be the response to natural forcing alone: That is, volcanic eruptions and variation in solar irradiance do not explain the warming in the latter half of the 20th century but they may have contributed to the observed warming in the first half." WGl TAR SPM & WGl
TAR chapter 12.
2.11 "In the light of new evidence and taking into account the remaining uncertainties, most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations. Detection and attribution studies (including greenhouse gases and sulfate aerosols as anthropogenic forcing) consistently find evidence for an anthropogenic signal in the climate record of the last 35 to 50 years, despite uncertainties in forcing due to anthropogenic sulfate aerosols and natural factors (volcanoes and solar irradiance). The sulfate and natural forcings are negative over this period and cannot explain the warming; whereas most of these studies find that, over the last 50 years, the estimated rate and magnitude of warming due to increasing greenhouse gases alone are comparable with, or larger than, the observed warming. The best agreement for the 1860-2000 record is found when the above anthropogenic and natural forcing factors are combined." WGI TAR SPM & WGI
TAR Chapter 12
2.12 "Changes in sea level, snow cover, ice extent, and precipitation are consistent with a warming climate near the Earth's surface (see Table 2-1).(Reproduced as Table 3 in Annex A) Some of these changes are regional and some may be due to internal climate variations, natural forcings, or regional human activities rather than attributed solely to global human influence." WGI TAR SPM & WGII
TAR Section 4.3.11
2.13 "It is very likely that the 20th century warming has contributed significantly to the observed rise in global average sea level and increase in ocean-heat content. Warming drives sea-level rise through thermal expansion of seawater and widespread loss of land ice. Based on tide gauge records, after correcting for land movements, the average annual rise was between 1 and 2 mm during the 20th century. The very few long records show that it was less during the 19th century. Within present uncertainties, observations and models are both consistent with a lack of significant acceleration of sea-level rise during the 20th century. The observed rate of sea-level rise during the 20th century is consistent with models. Global ocean-heat content has increased since the late 1950s, the period with adequate observations of subsurface ocean temperatures." WGl TAR sections, 11.2, & 11.3.2.

Table 2: Supporting evidence for future climate changes
Reference to IPCC Synthesis Report Supporting Evidence References to TAR provided in IPCC Synthesis Report
3.2 "Carbon dioxide concentrations, globally averaged surface temperature, and sea level are projected to increase under all IPCC emissions scenarios during the 21st century."  
3.3 "All SRES emissions scenarios result in an increase in the atmospheric concentration of CO2. For the six illustrative SRES scenarios, the projected concentrations of CO2 -- the primary anthropogenic greenhouse gas -- in the year 2100 range from 540 to 970 ppm, compared to about 280 ppm in the pre-industrial era and about 368 ppm in the year 2000. These projections include the land and ocean climate feedbacks." WGI TAR Section
3.4 "Model calculations of the concentrations of the primary non-CO2 greenhouse gases by year 2100 vary considerably across the six illustrative SRES scenarios." WGI TAR Section 4.4.5 & WGI TAR Box 9.1
3.5 "The SRES scenarios include the possibility of either increases or decreases in anthropogenic aerosols, depending on the extent of fossil-fuel use and policies to abate polluting emissions......sulfate aerosol concentrations are projected to fall below present levels by 2100 in all six illustrative SRES scenarios. This would result in warming relative to present day. In addition, natural aerosols (e.g., sea salt, dust, and emissions leading to sulfate and carbon aerosols) are projected to increase as a result of changes in climate." WGI TAR Section 5.5 & SRES (Special report on Emission Scenarios) Section 3.6.4
3.6 "The globally averaged surface temperature is projected to increase by 1.4 to 5.8°C over the period 1990 to 2100. This is about two to ten times larger than the central value of observed warming over the 20th century and the projected rate of warming is very likely to be without precedent during at least the last 10,000 years, based on paleoclimate data...... These results are for the full range of 35 SRES scenarios, based on a number of climate models." WGl TAR Section 9.3.3
3.8 "Globally averaged annual precipitation is projected to increase during the 21st century. Globally averaged water vapor and evaporation are also projected to increase." WGI TAR Section 9.3.1
3.9 "Global mean sea level is projected to rise by 0.09 to 0.88 m between the years 1990 and 2100, for the full range of SRES scenarios.....This is due primarily to thermal expansion and loss of mass from glaciers and ice caps." WGI TAR Section 11.5.1
3.10 "Substantial differences are projected in regional changes in climate and sea level, compared to the global mean change."  
3.11 "It is very likely that nearly all land areas will warm more rapidly than the global average, particularly those at northern high latitudes in winter. Most notable of these is the warming in the northern regions of North America, and northern and central Asia, which exceeds global mean warming in each model by more than 40%."  
3.14 "Glaciers and ice caps are projected to continue their widespread retreat during the 21st century. Northern Hemisphere snow cover, permafrost, and sea-ice extent are projected to decrease further. The Antarctic ice sheet is likely to gain mass because of greater precipitation, while the Greenland ice sheet is likely to lose mass because the increase in runoff will exceed the precipitation increase." WGI TAR Section 10.3.2 WGl TAR Section 11.5.4

Table 3: Table 2.1 of the IPCC Synthesis Report:
20th century changes in the Earth's atmosphere, climate, and biophysical system.Footnote a 

Concentration indicators

Atmospheric concentration of CO 2
280 ppm for the period 1000-1750 to 368 ppm in year 2000 (31±4% increase). [WGI TAR Chapter 3]

Terrestrial biospheric CO 2 exchange
Cumulative source of about 30 Gt C between the years 1800 and 2000; but during the 1990s, a net sink of about 14±7 Gt C. [ WG1 TAR Chapter 3 & SRLULUCF (Special Report on Land Use, Land Use Change, and Forestry)]

Atmospheric concentration of CH 4
700 ppb for the period 1000-1750 to 1,750 ppb in year 2000 (151±25% increase). [WGI TAR Chapter 4]

Atmospheric concentration of N 2O
270 ppb for the period 1000-1750 to 316 ppb in year 2000 (17±5% increase). [WGI TAR Chapter 4]

Tropospheric concentration of O 3
Increased by 35±15% from the years 1750 to 2000, varies with region. [WGI TAR Chapter 4]

Stratospheric concentration of O 3
Decreased over the years 1970 to 2000, varies with altitude and latitude. [ WGI TAR Chapters 4 & 6]

Atmospheric concentrations of HFCs, PFCs, and SF 6
Increased globally over the last 50 years. [WGI TAR Chapter 4]

Weather indicators

Global mean surface temperature
Increased by 0.6±0.2°C over the 20th century; land areas warmed more than the oceans (very likely). [WGI TAR Section]

Northern Hemisphere surface temperature
Increased over the 20th century greater than during any other century in the last 1,000 years; 1990s warmest decade of the millennium (likely). [WGI TAR Chapter 2 Executive Summary & Section]

Diurnal surface temperature range
Decreased over the years 1950 to 2000 over land: nighttime minimum temperatures increased at twice the rate of daytime maximum temperatures (likely). [WGI TAR Section]

Hot days / heat index
Increased (likely). [WGI TAR Section]

Cold / frost days
Decreased for nearly all land areas during the 20th century (very likely). [WGI TAR Section]

Continental precipitation
Increased by 5-10% over the 20th century in the Northern Hemisphere (very likely), although decreased in some regions (e.g., north and west Africa and parts of the Mediterranean). [ WGI TAR Chapter 2 Executive Summary & Section 2.5.2]

Heavy precipitation events
Increased at mid- and high northern latitudes (likely). [WGI TAR Section]

Frequency and severity of drought
Increased summer drying and associated incidence of drought in a few areas (likely). In some regions, such as parts of Asia and Africa, the frequency and intensity of droughts have been observed to increase in recent decades. [WGII TAR Sections 10.1.3 & 11.1.2]

Biological and physical indicators

Global mean sea level
Increased at an average annual rate of 1 to 2 mm during the 20th century. [WGI TAR Chapter 11]

Duration of ice cover of rivers and lakes
Decreased by about 2 weeks over the 20th century in mid- and high latitudes of the Northern Hemisphere (very likely). [ WGI TAR Chapter 2 Executive Summary & Section, & WGII TAR Sections 5.7 &]

Arctic sea-ice extent and thickness
Thinned by 40% in recent decades in late summer to early autumn (likely) and decreased in extent by 10-15% since the 1950s in spring and summer. [WGI TAR Section & WGII TAR Section]

Non-polar glaciers
Widespread retreat during the 20th century. [WGI TAR Section & WGII TAR Section 4.3.11]

Snow cover
Decreased in area by 10% since global observations became available from satellites in the 1960s (very likely). [WGI TAR Section]

Thawed, warmed, and degraded in parts of the polar, sub-polar, and mountainous regions. [ WGI TAR Sections & 11.2.5, & WGII TAR Section]

El Niño events
Became more frequent, persistent, and intense during the last 20 to 30 years compared to the previous 100 years. [WGI TAR Section 7.6.5]

Growing season
Lengthened by about 1 to 4 days per decade during the last 40 years in the Northern Hemisphere, especially at higher latitudes. [WGII TAR Section 5.2.1]

Plant and animal ranges
Shifted poleward and up in elevation for plants, insects, birds, and fish. [WGII TAR Sections 5.2, 5.4, 5.9, &]

Breeding, flowering, and migration
Earlier plant flowering, earlier bird arrival, earlier dates of breeding season, and earlier emergence of insects in the Northern Hemisphere. [WGII TAR Sections 5.2.1 & 5.4.3]

Coral reef bleaching
Increased frequency, especially during El Niño events. [WGII TAR Section 6.3.8]

Economic indicators

Weather-related economic losses
Global inflation-adjusted losses rose an order of magnitude over the last 40 years (see Q2 Figure 2-7). Part of the observed upward trend is linked to socio-economic factors and part is linked to climatic factors. [WGII TAR Sections 8.2.1 & 8.2.2]

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