1. Impact of Climate Change on Peri-Glacial Environments

2. Arctic(a) vs. Antarctica
land: 8 X 106 km2 (30% ice)
\ substantial terrestrial food
\ land mammals
\ herbivorous & insectivorous birds (high diversity)
land: 14 X 106 km2 (97% ice)
\ no terrestrial food
\ no land mammals
\ no herbivorous or insectivorous birds (low diversity)

3. “tundra” = treeless barrens
Tundra ecosystems
“tundra” = treeless barrens

4. Global distribution of tundra

5. Arctic ecosystems in Canada
N.Arctic = polar desert
S.Arctic = tundra

6. Tundra ecosystems
Tundra ecosystems are associated with areas of extreme near-polar climate which operates either directly, or through a series of environmental forcings (primarily thaw-layer dynamics) to limit productivity and biodiversity.

7. Tundra climate stations
Barrow
Treeline
Tiksi
Churchill
75°N
60°N
Svalbard
Iqaluit
Gulf Stream

8. Frost-free days
Treeline

9. Mean annual snowfall (mm)
Treeline

10. Permafrost distribution

11. Alaska
Siberia

12. Boreal forest Tundra mean location Polar Front tree growth Jan July
mean #d >10°C
frost-free days
pollen/seed
viability
mean #d <0°C
Boreal forest Tundra
patchy discontinuous continuous
Permafrost

14. Animal life

15. Climate change

16. Hockey Stick - Earth’s Temperature Variations: Past 1000 Years
The hockey stick has been the brainchild of Prof. Mann of the University of Virginia. It appeared in the IPCC2001 report but it has been highly controversial since some claim that it does not take into account the warm climate half a millennia ago. Prof Mann says it shows up in the gray area and Europe may be a special case.

17. Source: Arctic Climate Impact Assessment website

18. Associated Climate Changes
Global sea-level has increased 1-2 mm/yr; in 80 years a rise in sea level between 3.5 and 34.6 in. (up to 3ft) is expected
Duration of ice cover of rivers and lakes decreased by 2 weeks in N. Hemisphere
Arctic ice has thinned substantially, decreased in extent by 10-15%

19. Source: Intergovernmental Panel on Climate Change, 2001 Report
Reduced permafrost in polar, sub-polar, mountainous regions
Growing season lengthened by 1-4 days in N. Hemisphere
Retreat of continental glaciers on all continents
Snow cover decreased by 10% (reduced solar reflection)
Source: Intergovernmental Panel on Climate Change, 2001 Report

20. Since 1979, the size of the summer polar ice cap has shrunk more than 20 percent.
(Illustration from NASA) (

21. Recent (post-1950) climate change in polar regions
Arctic:
Reduction in sea ice extent and thickness
Northward treeline shifts (e.g. E. coast Hudson Bay)
Increased lakes, bogs (e.g. Ellesmere Island)
Range expansions (e.g. dragonflies - Inuvik )
Antarctic:
Ice shelf disintegration (e.g. N. Larsen & Wordie Shelf)
Spread of flowering plants (e.g. Antarctic hairgrass has expanded its range 25-fold since 1964)
New lichen species colonizing recently deglaciated areas

22. Polar Amplification- Feedbacks
Ice-Albedo Feedback –relevant to retreating perennial ice cover and also over land
Cloud feedback – positive or negative, depending on the height of clouds
Other feedbacks are mainly positive

23. Total Ice Cover/Monthly Anomalies
From 1978 to 1996,
the trend in the ice
extent was -2.2% per
decade. Since 1996,
the trend has changed
to -10.1% per decade
suggesting a large acceleration in the
decline.
Acceleration in the
decline makes it
difficult for ice to
recover because
of ice albedo feedback.
-10.1%/dec
The total ice cover has been a lot less variable, Overall the decline is 3.6 % per decade but in the first thirteen years of satellite data the deline was only about 2% per decade. From 1996, the slope shifted and the decline is now 11% per decade, and comparable with perennial ice data.
-10.7%/dec

24. Permafrost in Alaska
Not much has been done in terms of satellite analysis over permafrost regions. The reason is because sensor radiations do not penetrate through the surface to get subsurface information. We hope to change than through a combination of models and data.