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The Big Picture: a Changing Planet

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This group of indicators tracks important global driving forces that influence long-term changes at the global and Arctic scales. They provide information used in other focal points to analyze why some indicators are changing in the NWT. These changes can have significant direct and indirect effects on NWT environment.

 

This first focal point sets the stage for more detailed NWT indicators in other focal points.

 

Global climate indicators

1.1. Trends in global greenhouse gas concentrations

 

Air Quality Lab This indicator reports on global atmospheric concentrations of important long-lived greenhouse gases (GHGs) over the last 2,000 years.

This information is summarized from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis published by the World Meteorological Organization and the United Nations Environment Programme7. Current global carbon-dioxide (CO2) concentration is obtained from US National Oceanic and Atmospheric Administration.

NWT Focus

Increases in global GHG concentrations are partly responsible for the noticeable changes in the NWT’s climate during the past three decades, and are having complex effects on the NWT’s environment.

Current view: status and trend

  • “Global atmospheric concentrations of carbon dioxide, methane and nitrous oxide have increased markedly as a result of human activities since 1750 and now far exceed pre-industrial values determined from ice cores spanning many thousands of years. The global increases in carbon dioxide concentration are due primarily to fossil fuel use and land use change, while those of methane and nitrous oxide are primarily due to agriculture.”

Quote from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis Global: FAQ.7

The graph shows recent monthly mean carbon dioxide globally averaged over marine surface sites. The Global Monitoring Division of NOAA/Earth System Research Laboratory has measured carbon dioxide and other greenhouse gases for several decades at a globally distributed network of air sampling sites. A global average is constructed by first fitting a smoothed curve as a function of time to each site, and then the smoothed value for each site is plotted as a function of latitude for 48 equal time steps per year. A global average is calculated from the latitude plot at each time step. Source courtesy of: National Oceanic & Atmospheric Administration at http://www.esrl.noaa.gov/gmd/ccgg/trends/global.html. Historic trends in CO2 can be viewed at http://www.esrl.noaa.gov/gmd/ccgg/trends/history.html.

Atmospheric concentrations of important long-lived greenhouse gases over the last 2,000 years. Increases since about 1750 are attributed to human activities in the industrial era. Concentration units are parts per million (ppm) or parts per billion (ppb), indicating the number of molecules of the greenhouse gas per million or billion air molecules, respectively, in an atmospheric sample. Source courtesy of: IPCC WG1-2007 "The Physical Science Basis" Report; FAG 2.1. Data from various sources, including from glaciers.


CO2 concentration from Alert, NU. Data courtesy Doug Worthy, Environment Canada.

While there are no long-term records of atmospheric CO2 measurements for the NWT, there are measurements for Alert, NU (above).

Looking forward

  • "There is high agreement and much evidence that with current climate change mitigation policies and related sustainable development practices, global GHG emissions will continue to grow over the next few decades."
  • "Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century."

Quotes from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis Global: Summary for Policy Makers.7

Find more

  • For more information on global climate change go to the International Panel on Climate Change at http://www.ipcc.ch/.

Other Focal Points

Updated: September 2011

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1.2. Trends in average global temperature, sea levels and snow cover

This indicator reports on measured changes in global average surface temperature and sea level, and changes in snow cover for March-April in the Northern Hemisphere.

This information is summarized from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis published by the World Meteorological Organization and the United Nations Environment Programme7.

NWT Focus

Increases in temperature and sea levels around the world are partly responsible for the noticeable changes in NWT’s climate during the past three decades, and are having complex effects on the NWT environment. Temperature and snow cover are compared to similar indicators at the NWT level in the CLIMATE and WEATHER focal point.

Current view: status and trend

  • “At continental, regional and ocean basin scales, numerous long-term changes in climate have been observed. These include changes in arctic temperatures and ice, widespread changes in precipitation amounts, ocean salinity, wind patterns and aspects of extreme weather including droughts, heavy precipitation, heat waves and the intensity of tropical cyclones.”

  • Eleven of the last twelve years (1995–2006) rank among the 12 warmest years in the instrumental record of global surface temperature (since 1850). The linear warming trend over the last 50 years … is nearly twice that for the last 100 years. The total temperature increase from 1850–1899 to 2001–2005 is 0.76°C.”

  • “Average sea level rose at an average rate of 1.8 [1.3 to 2.3] mm per year over 1961 to 2003. The rate was faster over 1993 to 2003. …[How this trend] reflects decadal variability or an increase in the longer term trend is unclear.”

  • “Mountain glaciers and snow cover have declined on average in both hemispheres. Widespread decreases in glaciers and ice caps have contributed to sea level rise (ice caps do not include contributions from the Greenland and Antarctic Ice Sheets).”

Quotes from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis Global.9

(a) Global average surface temperature, (b) global average sea level from tide gauge (blue) and satellite (red) data and (c) Northern Hemisphere snow cover for March-April. All changes are relative to corresponding averages for the period 1961–1990. Smoothed curves represent decadal average values while circles show yearly values. The shaded areas are the uncertainty intervals estimated from a comprehensive analysis of known uncertainties (a and b) and from the time series Source courtesy of: IPCC WG1 AR4 Report; Figure SPM.3.

Looking forward

  • “For the next two decades, a warming of about 0.2°C per decade is projected for a range of SRES emission scenarios. Even if the concentrations of all greenhouse gases and aerosols had been kept constant at year 2000 levels, a further warming of about 0.1°C per decade would be expected. “

Quote from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007: - The Physical Science Basis Global.

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Other Focal Points

Updated: September 2011

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Arctic climate indicators

1.3. Projected trends in temperature and precipitation in the Arctic

This indicator reports on projected changes in Arctic temperature and precipitation based on climate change models.

This information is summarized from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis published by the World Meteorological Organization and the United Nations Environment Programme.7

 

NWT Focus

Changes in global climate can differ in different parts of the world. This indicator provides more detailed observations and predictions on climate changes that are directly affecting the environment in the NWT.

 

Current view: status and trend

  • “(Winters) …are likely to (get warmer)… in northern North America. “
  • “Snow season length and snow depth are very likely to decrease in most of North America, except in the northernmost part of Canada where maximum snow depth is likely to increase.”
  • “The uncertainties in regional climate changes over North America are strongly linked to the ability of (climate models) to reproduce the dynamical features affecting the region … Atmosphere-Ocean General Circulation Models exhibit large model-to-model differences in ENSO and NAO/Arctic Oscillation (AO) responses to climate changes. Changes in the Atlantic … are uncertain, and thus so is the magnitude of consequent reduced warming in the extreme north-eastern part of North America; cooling here cannot be totally excluded. The Hudson Bay and Canadian Archipelago are poorly resolved by (climate models), contributing to uncertainty in ocean circulation and sea ice changes and their influence on the climate of northern regions.”

 

Quotes from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007: - The Physical Science Basis Global:7 Chapter 11, p. 887

“Temperature anomalies with respect to 1901 to 1950 for the whole Arctic for 1906 to 2005 (black line) as simulated (red envelope) by MMD models incorporating known forcings; and as projected for 2001 to 2100 by MMD models for the A1B scenario (orange envelope). The black line is dashed where observations are present for less than 50% of the area in the decade concerned.” Source: courtesy of: IPCC WG1 AR4 Report Fig 11.18. ARC = Arctic

“… changes in surface air temperature (°C, left), precipitation (mm day–1, right) ... for winter (DJF, top) and summer (JJA, bottom) predicted by climate change models for 2080-2099 relative to 1980-1999. Stippling denotes areas of uncertainty in the models. The largest increase is predicted for the Arctic, where winters will be more than 7.5 °C warmer on average in 100 years. Source: courtesy of: IPCC WG1 AR4 Report Fig 10.9. Partial

  • “The ensemble mean of the … models projects a general decrease in snow depth …as a result of delayed autumn snowfall and earlier spring snowmelt. In some regions where winter precipitation is projected to increase, the increased snowfall can more than make up for the shorter snow season and yield increased snow accumulation. Snow depth increases are projected by some (climate change models) over some land around the Arctic Ocean … and by some (regional climate models) in the northernmost part of the Northwest Territories (Figure 11.13).”

Quotes from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007: - The Physical Science Basis Global7: Chapter 11, p. 892

“Percent snow depth changes in March (only calculated where climatological snow amounts exceed 5 mm of water equivalent), as projected by the Canadian Regional Climate Model (CRCM; Plummer et al., 2006), driven by the Canadian General Circulation Model (CGCM), for 2041 to 2070 under SRES A2 compared to 1961 to 1990. Source: courtesy of: IPCC WG1 AR4 Report Fig 11.13

Looking forward

  • “The Arctic is very likely to warm during this century more than the global mean. Warming is projected to be largest in winter and smallest in summer. Annual arctic precipitation is very likely to increase. It is very likely that the relative precipitation increase will be largest in winter and smallest in summer.”
  • “Interannual variability over North America is connected to two large-scale oscillation patterns, ENSO and the NAO/AO The … model projections indicate (more intense) polar vortex and many models project a decrease in the arctic surface pressure, which contributes to an increase in the AO/NAO index ; the uncertainty is large, however, due to the diverse responses of (climate models)… The …model projections indicate a shift towards (more) El-Niño like conditions.. There is a wide range of behaviour among the current models, with no clear indication of possible changes in the amplitude or period of El Niño.” (see Focal point NATURAL CLIMATE FLUCTUATIONS for definitions of ENSO, NAO/AO and El Niño).

Quotes from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007: - The Physical Science Basis Global7: Chapter 11.

The authors of the overview document of the Arctic Climate Impact Assessment identified these key findings:

  • -The Arctic climate is now warming rapidly and much larger changes are projected.
  • -Arctic warming and its consequences have worldwide implications.
  • -Arctic vegetation zones are projected to shift, bringing wide-ranging impacts.
  • -Animal species' diversity, ranges, and distribution will change.
  • -Many coastal communities and facilities face increasing exposure to storms.
  • -Reduced sea ice is very likely to increase marine transport and access to resources.
  • -Thawing ground will disrupt transportation, buildings, and other infrastructure.
  • -Indigenous communities are facing major economic and cultural impacts.
  • -Elevated ultraviolet radiation levels will affect people, plants, and animals.
  • -Multiple influences interact to cause impacts to people and ecosystems.

Quote from the 2004 Arctic Climate Impact Assessment. Policy Document4.

These predicted impacts can be tracked using indicators described in the relevant focal points of the State of the Environment report.

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Other Focal Points


Updated: September 2011

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1.4. Trends in Arctic sea ice.

Beaufort SeaThis indicator reports on trends in observed Arctic sea ice, and observed changes to projected changes based on climate models.

This indicator is based on satellite data1, and provides analyses from Environment Canada's Sea Ice Service2,7, and the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007 - The Physical Science Basis published by the World Meteorological Organization and the United Nations Environment Programme10.

NWT Focus

Changes in global climate are predicted to be greater and more rapid in the Arctic than elsewhere. This indicator provides more detailed observations and predictions on ice in the Beaufort Sea. Sea ice is an important habitat component for Arctic wildlife and an important factor affecting local and global climate. Changes in the formation of Arctic ice are affecting the NWT environment in a complex way.

This indicator provides information for the entire Arctic Ocean and  for the Beaufort Sea that can be compared with more detailed information in the Focal Point CLIMATE and WEATHER. The text is updated based on information from the Canadian Ice Service16.

Current view: status and trend

Trends in the Arctic Ocean

Mean sea ice anomalies, 1953-2010: Sea ice extent departures from monthly means for the Northern Hemisphere. For January 1953 through December 1979, data have been obtained from the UK Hadley Centre and are based on operational ice charts and other sources. For January 1979 through September 2010, data are derived from passive microwave (SMMR / SSM/I). Image by Walt Meier and Julienne Stroeve, National Snow and Ice Data Center, University of Colorado, Boulder. 

  • ” Satellite data from the SMMR and SSM/I instruments have been combined with earlier observations from ice charts and other sources to yield a time series of Arctic ice extent from the early 1900s onward. While the pre-satellite records are not as reliable, their trends are in good general agreement with the satellite record and indicate that Arctic sea ice extent has been declining since at least the early 1950s.”

Quote from the National Snow and Ice Data Center Webpage1.

The largest reductions in sea ice occur on thick multi-year ice in summer. So far, the sharpest decline in sea ice minimum cover occurred in 2007.

A reduction in sea ice thickness of about 43% was recorded between 1988 and 20055. Thinning of sea ice is also measured as an increase in the proportion of first-year ice (thinner) compared to multi-year ice (thicker). This thinner ice is more mobile and its movement can be greatly influenced by storm activities and ocean currents. The vulnerability of thin ice to ocean currents was demonstrated by the dramatic and previously unobserved opening of a large flaw lead in the Beaufort Sea just off the western coast of Banks Island in December 2007 - January 20089.

In December 2007, a massive fracture of the Beaufort Ice pack was observed west of Banks Island. Source: Image from NOAA, courtesy of: Environment Canada, Canadian Ice Service, Education Corner, Beaufort Sea9: http://www.ice.ec.gc.ca/app/WsvPageDsp.cfm?id=11892&Lang=eng. Image from NOAA.

Trends in the Beaufort Sea

Reductions in sea ice cover during the fall minimum are not occurring at the same rate everywhere5.  Sea ice trend studies for the Canadian Arctic indicate that while some areas show significant negative trends, many areas do not yet display detectable trends.15 The most rapid changes are occurring in the Arctic basin, north of Alaska, and in the Barents Sea, north Scandinavia.  There is no decline in sea ice concentration in some areas, such as north of the Canadian Archipelago and in the Beaufort Sea west of Banks Island5.  This mostly occurs because ice is being piled up by the normal clockwise motion of the entire Arctic ice pack called the Beaufort Gyre.

Reductions in ice cover and ice thickness are resulting in increased vulnerability of Arctic coastal communities to storm surges and coastal erosion5(see Indicator 1.7, Sea Level Rises). Local knowledge studies indicate that changes in sea ice are resulting in increasing dangers during off-shore travels, especially in fall and spring5,8,13.
Reduced sea ice, earlier break-up of sea ice and more fall storms have resulted in more shore erosion in the Inuvialuit Settlement Region8,12.



Figure A: Trends in summer Total Accumulated Coverage for all ice types combined, 1966-2010. Trends are expressed a percent change per decade. Figure B: Trends in summer Total Accumulated Coverage for old ice only, 1966-2010. Trends are expressed as a percent change per decade.Source: Canadian Ice Service16. Tivy, A., S. E. L. Howell, B. Alt, S. McCourt, R. Chagnon, G. Crocker, T. Carrieres, and J.J. Yackels (2011), Trensd and variability in summer sea ice cover in the Canadian Arctic based on the Canadian Ice Service Digital Archive, 1960-2008 and 1968-2008, J. Geophys. Res., 116, CO3007, doi:10.1029/2009JC005855.

September 2008 broke the 1998 record for minimum sea ice extents and concentrations in the Beaufort Sea.  While 2007 was the record minimum year for the whole Arctic Ocean, it was not a record minimum year for the Beaufort Sea. As well, 2008 broke the 2007 record for September minimum sea ice volume in both the Beaufort Sea and in the Arctic as a whole16.  This is related to the large loss of thick, multi-year sea ice from the Arctic Ocean as a result of melting in summer 2007 and as a result of enhanced transport of sea ice from the Arctic Ocean into the North Atlantic via the Fram Strait in winter 2007-08.

There is a significant negative trend in summertime ice amounts of all ice types along the Alaskan Coast.  This is primarily related to increasing sea surface temperatures in this area16.

There is a significant positive trend in summertime multi-year (MY) ice amounts just west of Banks Island.  This is primarily related to variations in the Beaufort Gyre (a clockwise circulation), related to variations in atmospheric winds, which sometimes brings greater-than-normal amounts of MY ice into this area16.

Linking ice to biodiversity

Ice

Biodiversity 

 Season

Ice edges
and polynyas

Enhanced primary production due to light and nutrients. They can support intense phytoplankton blooms (Wang et al. 2005) which
are important to invertebrates and Arctic Cod then to other species, such as birds and mammals.

Any time   

First-year
landfast ice

Ice algae provide an early and abundant food source for planktonic grazers, such as pelagic copepods and amphipods,at a time
when other food sources are not available (Hill and Cota 2005, Michel et al. 1996) 

Late Fall

Heavy ice

Barrier to feed for birds and polar bears, barriers to breathing for whales 

Any time

Source: Canadian Biodiversity: Ecosystem Status and Trends Report. Available at www.biodivcanada.ca.

Looking forward

Raw data and analyses are shared across the world, including with scientists in Canada. This information was used by the International Panel on Climate Change to make predictions about the future extent of sea ice in the Arctic based on climate models:

  • “Arctic sea ice is very likely to decrease in its extent and thickness. It is uncertain how the Arctic Ocean circulation will change”

Quote from the Fourth Assessment Report of the International Panel on Climate Change - Climate Change 2007: - The Physical Science Basis Global10: Chapter 11.

The effects of Arctic Ocean circulation on the rate of decline in Arctic sea ice have been extensively studied and are proving to have an important role in the extremely fast reduction of summer sea ice compared to what were expected based on climate change models:

  • “Examination of the long-term satellite record dating back to 1979 and earlier records dating back to the 1950s indicate that spring melt seasons have started earlier and continued for a longer period throughout the year… Even more disquieting, comparison of actual Arctic sea ice decline to projections from the (Fourth Assessment Report of the International Panel on Climate Change -AR4) show that observed ice loss is faster than any of the …models have predicted …” .

Quote from the National Snow and Ice Data Center webpage1.

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Other Focal Points

Updated: August 2011

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Global demographic and economic indicators

1.5. Trends in global population numbers

 

This indicator reports on actual changes in human populations on the planet. This information is summarized from the United Nation Year Book19 and information from the UN Population Division17.


UN Yearbook series. Collage courtesy of UN.

NWT Focus

Increasing global human population is linked (directly and indirectly) to increases in greenhouse gas emissions, to changes in long-range contaminants in northern regions, including the NWT, and to changes in demands for the NWT’s resources. This global indicator is compared with similar indicators for the NWT in the DEMOGRAPHY focal point.

Current view: status and trend

By 2005, the estimated world population had reached 6.5 billion people and global population density was estimated as an average of 48 people per km2 of the earth’s land surface area. In contrast, the NWT population density is 0.036 people per km2.6

Source: 1950-2005 population estimates courtesy of 2005 UN Statistics Yearbook19.

Projected estimates courtesy of Wikimedia3 Commons with data from UN World Population Prospects18. Vertical axis is logarithmic.

Looking forward

The global human population growth rate has been slowing down since the 1960s18
.

Other Focal Points

Updated: April 2011

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1.6. Trends in global supply and demand for northern natural resources.

This indicator reports on prices for some commodities that are important to the NWT economy. The natural resource price index provides an indicator of the global supply and demand for the NWT’s main renewable and non-renewable resources that sell on the world market.

This information is summarized from the Statistics Canada report Human Activity and the Environment 201114. Text and analysis is from the EnvironStats report ”Canada’s natural resource wealth at a glance”11 tracking the natural resource price index as measured by the “overall price change for the bundle of resources considered”11. These resources are grouped as Energy ( natural gas, crude oil, oil sands* , and coal), Minerals ( gold-silver, nickel-copper, copper-zinc, lead-zinc, molybdenum, uranium, potash and diamonds), and Timber (timber stocks that are physically accessible and available for harvesting). Most of these resources, except potash, are present in the NWT.

The fur price indicator tracks the average annual price obtained per marten pelt. Marten is the most important species in terms of revenue for the NWT’s fur industry. GNWT Industry, Tourism, and Investment compiles information on pelts sold at international auctions in Canada.

NWT Focus

As prices for natural resources go up or down, prospects for exploration and development and of some of the NWT resources also change. These driving forces have affected past land use patterns in the NWT, and will continue to affect the NWT environment in the future. Fur prices are one of the main causes for changing participation in the trapping portion of the traditional economy in the NWT.

Current view: status and trend

Energy, Minerals and Timber

  • “Unless set by regulatory agencies or organizations, the price of any good or resource is typically determined by supply and demand. The supply of natural resources is usually fixed in the short-term. In the long-term, however, the supply is affected by a number of factors including changes in resource prices, advancement of extraction technologies as well as discoveries of new deposits and depletion of resources.’
  • “On the other hand, demand for most natural resources is variable in both the short and long run, being affected by fluctuations in domestic and global economic factors. When resource demand rises in the short term, constraints on short-term supply can mean sharp increases in prices. This effect can be seen in the price index of natural resources …, which has been volatile over the past decade, mainly due to fluctuating demand.”
  • “On average, the all-items natural resource price index grew more than 9% per year from 1997 to 2006. Declines in resource prices in 1998 and 2002 were related to the 1997/98 East Asian financial crisis, and the terrorist attack of September 11, 2001, which triggered slowdowns in the global economy. Between 2002 and 2006, the price index of natural resources increased rapidly.”
  • “In recent years, the real GDP of India and China, the world’s two most populated countries, grew more than 8% a year. These countries are both large importers of natural resources. In particular, China’s demand for industrial raw materials has pushed up world energy and metal prices.”
  • “Volatility in the energy resource price index was the main factor for the volatility in the all-items resource price index. During the last decade, the energy resource price index grew on average by 12% per year, followed by minerals (7%) and timber (2%).”

Quotes from Canada’s Natural Resource Wealth at a Glance10.

Source: Statistics Canada. Natural resource price index. 1990-2009. From Human Activity and the Environment 2011: "Economy and the Environment"14, available from http://www.statcan.gc.ca/daily-quotidien/110628/dg110628a-eng.htm.

Marten Pelts

Fur prices increased steadily after the Second World War when a large influx of women in the job market created a strong demand for fur items that had previously only been available to the wealthy few. By the late 1980s the demand and price for furs had increased to an all-time high. Prices collapsed in the early 1990s with large-scale campaigns for the abolition of trapping and changes in the fashion industry. By 2000, the price of marten pelts had returned to about the same value, accounting for inflation, as the 1960s. China is a major importer of Canadian furs. With the increase in the Chinese economy, the price of fur has increased in the past decade and by 2005-06 had reached the same level seen in the early 1980s.

Source: GNWT ITI - Average price of marten fur pelts sold at international auctions (pink). Adjusted (blue) for inflation to 2008 equivalent in Canadian dollars using the Bank of Canada Inflation calculator at http://www.bankofcanada.ca/en/rates/inflation_calc.html For example, due to inflation, receiving $6.71 for a pelt in 1958 was equivalent to receiving $51.53 for it in 2008.

Looking forward

  • “When prices increase, businesses not only boost production to earn profits but also invest more in exploration and drilling activities. This may result in the discovery of new deposits. Also, with increased prices, previously known but unprofitable resources may become profitable to extract, which in turn increases the size of the economically recoverable reserve.”

On the other hand, when prices decrease, exploration and production decrease.

  • “From 1997 to 2006, the all-items extraction cost index grew, on average, by 10% per year. This increase was mainly due to the increase in labour and capital costs in recent years.”

Quotes from Canada’s Natural resource wealth at a glance11.

 

The price of pelts on international markets can vary with the global economy and fashion. They also vary depending on winter weather. Warm winters in China and other major fur buying areas result in low fur sales. Warm winters in the NWT produce poor quality furs, resulting in low prices. On the other hand, an extremely cold or snowy season may reduce pelt availability, increase demand and increase price. Competition from the wage economy can also reduce the number of furs harvested, reducing supply and increasing price. How weather and competition will affect the future of the trapping industry in the NWT is uncertain.

Find More

  • Go to the Human Activity and the Environment reports for more information on environmental indicators across Canada, at http://www.statcan.ca/. 

Other Focal Points


Updated: September 2011

Reference List

Ref 1 - 2008, National Snow and Ice Data Centre, University of Colorado  Boulder, CO, http://nsidc.org/sotc/sea_ice.html

Ref 2 - 2008, State of the Canadian Cryosphere, Environment Canada,  http://www.socc.ca/seaice/seaice_hist_e.cfm

Ref 3 - Barber, D. G. Lukovich J. V. Keogak J. Baryluk S. Fortier L.  Henry G. H. R., 2008, The changing climate of the Arctic,  Arctic, 61,(suppl. 1):7- 26 

Ref 4 - Canadian Ice Service, 2009, Sea Ice Overview, Environment Canada. http://ice.ec.gc.ca/App/WsvPageDsp.cfm;jsessionid=2ABF98429B8D18A18C9BD360F4E5C165?Lang=eng&lnid=3&ScndLvl=no&ID=10160 

Ref 5 - Communities of Aklavik, Inuvik Holman Island Paulatuk and  Tuktoyaktuk Nickels S. Buell M. Furgal C. Moquin H., 2005,  Unikkaaqatigiit – Putting the Human Face on Climate Change: Perspectives from the Inuvialuit Settlement Region.,  Ottawa:Joint publication of Inuit Tapiriit Kanatami, Nasivvik  Centre for Inuit Health and Changing Environments at Université  Laval and the Ajunnginiq Centre at the National Aboriginal  Health  Organization. http://www.itk.ca/sites/default/files/Inuvialuit.pdf

Ref 6 - Environment Canada, 2009, Education Corner, Beaufort Sea,  Environment Canada, Canadian Ice Service website,  http://www.ice.ec.gc.ca/app/WsvPageDsp.cfm?id=11892&Lang=eng

Ref 7 - International Panel on Climate Change., 2007, Climate Change  2007 - The Physical Science Basis. Contribution of Working  Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change , Solomon, S., D.  Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor  and H.L. Miller, World Meteorological Organization and the  United Nations Environment Programme, Cambridge University  Press, Cambridge, United Kingdom and New York NY, USA. http://www.ipcc.ch/http://ipcc-wg1.ucar.edu/wg1/wg1-report.html

Ref 8 - Manson, G. K. and Solomon, S. M., 2007, Past and future forcing  of Beaufort sea coastal change, Atmosphere-Ocean, 45,(2):107-  122

Ref 9 - Pearce, T. D, Smit, B., Duerden, F., Ford, J., Goose, A.,  Inuktalik, R., and Kataoyak, F., 2006, Community adaptation and  vulnerability to climate change in Ulukhaktok, Conference and  Youth Forum 11-18 August 2006, Tuktoyaktuk, Northwest  Territories,

Ref 10 - Tivy, A. S. Howell B. Alt S. McCourt J. Yackel and T.  Carrieres, 2009, Trends and variability in summer sea ice cover  in Canada's arctic and sub-arctic regions (in prep)., To be  submitted to either the Journal of Geophysical Research or to  Atmosphere-Ocean.,

Ref 11 - Trudy Wohlleben, 2008, Sea Ice Thickness/Distribution Trends,  Canadian Wildlife Directors Committee Meeting, Ottawa, October  29-31, 2008,

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Global oceanic indicators

1.7. Projected trends in Beaufort Sea levels

This indicator reports on sea-level projections at coastal communities in the Northwest Territories.

Beaufort Sea Shores - Cape Bathurst. Copyright ENR/S Carriere.

Sea-level projections are estimated in Arctic regions by combining data on global sea level changing due to a warming climate, postglacial rebound (“vertical land motion”), and sea-level fingerprinting - the contribution to global sea-level rise from each major ice-cap in the world.  This indicator also presents evidence of the effects of sea-level rise on the Mackenzie Delta and on other coastal areas along the Beaufort Sea in the NWT.

Sea-level projections for NWT communities along the Beaufort Sea were estimated for this NWT State of Environment report  by Thomas James, Geological Survey of Canada, Natural Resources Canada, based on the methods described in a study generated by the Nunavut Climate Change Partnership3.  Estimates and uncertainties of vertical crustal motion were derived from information on past sea levels, as described in James et al. (2011)3.

This indicator is an output of the Earth Sciences Sector (ESS) Climate Change Geoscience Program of Natural Resources Canada.  Text and calculations are by Thomas James, peer-reviewed by Don Forbes.   This is ESS contribution number 20110177. The “NWT focus” and “looking forward” sections were drafted by ENR, GNWT.

NWT Focus

Increases in sea levels are partly responsible for the observed and projected changes on the Mackenzie Delta ecosystem and other coastal areas in the NWT.   Projected sea-level changes in the Beaufort Sea are an important component of future changes to NWT coasts and have the potential to affect infrastructure, ecosystems, and biodiversity (see Focal point Genetic Resources.

Global sea levels

Globally, sea level is projected to rise through the twenty-first century by at least a few tens of centimetres5,and possibly by more than one metre2,8,9. Sea-level rise greater than two metres by the year 2100 appears to be physically implausible.7

Vertical land motion

Locally, the amount of sea-level change is affected by two additional factors.  First, vertical land motion affects the amount of sea-level change that is experienced locally.  If the land is sinking, sea-level rise will be increased locally, and if the land is rising, sea-level rise will be decreased locally.  In the Canadian Arctic, vertical land motion is occurring primarily as a delayed response to the surface unloading caused by the thinning and retreat of the continental ice sheets at the end of the last ice age.  This delayed response is called postglacial rebound or glacial isostatic adjustment.

Unlike some parts of Nunavut, such as western Hudson Bay, where the land is rising quite rapidly at nearly one centimetre per year, coastal communities in the NWT are located near the periphery of the former ice sheet and vertical land motion is much slower.

Within the periphery of the former ice sheet, the land was pushed down during glaciation, and, deep within the Earth, material flowed horizontally away from the region of loading, causing uplift outside the ice sheet. Now that the ice sheet is gone, depressed regions are rising and regions that were uplifted are sinking. In the Northwest Territories, vertical land motion ranges from uplift of about 1 mm/year in the east at Ulukhaktok, to no motion at Paulatuk, to subsidence of 1 mm/year and 2.5 mm/year at Sachs Harbour and Tuktoyaktuk, respectively. The rates have an uncertainty of 2 mm/year. This is an estimate of the vertical motion of bedrock, and does not take into account subsidence due to compaction or thawing permafrost, nor does it take into account possible vertical motion due to tectonic activity.  Continued and new monitoring with Global Positioning System (GPS) installations will, with time, provide direct observations of vertical crustal motion at sites of interest.  Recent progress with new processing strategies and updated reference frames is very promising.

Sea-level fingerprinting

The second factor that affects projections of local sea-level change is the uneven redistribution of meltwater from glaciers, ice caps, and ice sheets.  The effect is called sea-level fingerprinting.  Owing to the reduced gravitational attraction of a shrinking ice mass, sea level falls close to a body of ice that is shrinking and providing meltwater to the oceans.  In the Canadian Arctic, the effect is quite important.  For example, if Greenland is contributing one millimetre per year to global sea-level rise, locally sea level will fall by 1.2 mm/yr at Iqaluit.  Further away, the effect is smaller.  In coastal communities in the Northwest Territories the local sea level rise ranges from +0.2 mm/yr (Tuktoyaktuk) to -0.1 mm/yr (Ulukhaktok) for a 1 mm/yr Greenland contribution to global sea-level rise. Paulatuk and Sachs Harbour have intermediate values.  Because the Greenland ice sheet is an important contributor to global sea-level rise projections, sea-level fingerprinting reduces projections of local sea-level rise in the Canadian Arctic.

Projected sea-level NWT communities along the Beaufort Sea  

Sea-level projections for four coastal communities of the Northwest Territories, based on assumptions and methods of James et al. (2011).  Scenarios of global sea-level change ranging from 28 to 115 cm of sea-level rise between 2010 and 2100 were analyzed to determine local projections of sea-level rise, taking into account vertical crustal motion and sea-level fingerprinting. Source: chart and estimates from Thomas James, NRCAN, done for this report.

Looking forward

Outer Mackenzie Delta after 1999 – storm surge dead zone shows up in brown. © AANDC(INAC)/S Kokelj.

For the Beaufort Sea coast, all information point to some increase in sea levels at most NWT communities. The Beaufort Sea coastline, on the mainland and elsewhere, is rich in ice and unconsolidated, and has been eroding quickly4.

It is predicted that sea level rise, working in concert with autumn storms4 and reduced sea ice, will result in increasing exposure of the Mackenzie Delta to extensive storm surges6. In 1999, an exceptionally high surge moved salt water far above the normal surge lines, transforming the outer delta ecosystem, killing shrubs and changing the ecology of some delta lakes from freshwater systems to brackish ones6. Evidence from traditional knowledge, shrub growth (dendrochronology) and lake diatoms show that this type of large scale storm surge had never occurred in the Mackenzie Delta in the past 1,000 years. This type of event may become the new norm6.

Looking Around

NWT projections of sea-level rise, for 90 years to the year 2100, were generated for this report using the methods and assumptions of James et al. (2011)3. In their study, sea-level projections were generated for five Nunavut communities, taking into account vertical land motion and sea-level fingerprinting, as described above. Their assessment of the likely amount of global sea-level change, based on the available scientific literature, ranged from 28 cm to 115 cm from 2010 to the year 2100 (a range of 87 cm).

Iqaluit is projected to experience a sea level rise of up to 70 cm by 21003. Not all Arctic coastal areas have projected sea level rise. Sea levels could decrease along the western coast of Hudson Bay – by as much as 70 cm at Arviat and 75 cm at Whale Cove in the next 90 years (from 2010 to 2100)3.

Find More

Other Focal Points

Updated: September 2011

References List

Ref 1

- Dyke, A.S. 1996. Preliminary paleogeographic maps of glaciated North America. Geological Survey of Canada, Open File 3296.

Ref 2 - Grinsted, A., Moore, J.C., and Jevrejeva, S. 2009. Reconstructing sea level from paelo and projected temperatures 200 to 2100 AD. Climate Dynamics, 24, 461-472.

Ref 3 - James, T.S., Simon, K.M., Forbes, D.L., Dyke, A.S., and Mate, D.J., 2011. Sea-level projections for five pilot communities of the Nunavut Climate Change Partnership; Geological Survey of Canada, Open File 6715, 23 p.

Ref 4 - Krupnik I., Jolly D., (eds)., 2002. The Earth is faster now; Indigenous observations of Arctic environmental change, Fairbanks, AK.

Ref 5 -
Meehl, G.A., et al. 2007. Global Climate Projections. In: Climate Change 2007: The Physical Science Basis, contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, ed S. Solomon and others, Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

Ref 6 - Pisaric, M.F.J., Thienpoint J.R.K.S.V, Nesbitt H.L.T.C, Solomon S., Smol J. P., 2011. Impacts of a recent storm surge on an Arctic delta ecosystem examined in the context of the last millenium. Proceedings of the National Academy of Sciences 108:8960-8965.

Ref 7
- Pfeffer, W.T., Harper, J.T. and O'Neel, S. 2008. Kinematic constraints on glacier contributions to 21st-century sea-level rise. Science, 321, 1340-1343.

Ref 8 - Rahmstorf, S. 2007. A semi-empirical approach to projecting future sea-level rise. Science, 315, 368-370.

Ref 9
- Vermeer, M., and Rahmstorf, S. 2009. Global sea level linked to global temperature. Proceedings of the National Academy of Sciences, 106, 21527-21532.

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