INFERENCE AND STRESS

• So if the normal ways of testing do not always apply how can we spot a system under stress early enough to control damage?

1 Impaired biological Productivity– Need to have the average level of production– What has been seen - over as many years as

possible– a variation in this level may indicate a problem

• Causes could include– Natural swing in population and system

dynamics - or– Intervention

2 Reduction in Species Diversity– We should have a count of populations (species

and within species)• nice in theory

– Populations do vary naturally but if the number of species is dropping then even though the functions are continuing, the system is probably under stress (looks normal but is not)

3 Shifts toward more Opportunistic Species

– If a species number increases the system is probably undergoing stress

– example in urbanization, the proliferation of gulls, racoons, hornets, certain ‘weeds’

– Current statistics indicate that 16times more raccoons or skunks livein urban areas as compared to the same size rural area (Mississauga)

4 Change in the Succession Pattern

– Expect ecosystems to change and in an orderly, predictable pattern

– reversal or change to the pattern means a problem

• plants and animals are not adapting in expected patterns

5 Reduction in the average size of the dominant biota

6 Higher disease susceptibility

– Diseases and pests start to show up in the population

– fish in Lake Ontario with tumours and cancers

– resistance may drop because of another stress (indirect) or direct with chemical poisonings

• PROBLEMS IN ALASKA– W. Stevens New York Times Oct. 98

A In Nanana (near Fairbanks ) there has been a large lottery based on the date the Tanana River ice breaks up in the spring. In the 81 years four of the earliest breaks have been in the 1990’s

B The Columbia Glacier has changed in the last few years

• First studied a century ago it was advancing so rapidly that ice blocks would fall off the nose of the glacier and crush trees in front of it

• The advance stopped in 1923 and stayed at one point retreating in summer and moving back in winter

• May and September of 2007

• The glacier rapidly retreating by about half a mile (1.6 kilometers)

• A volume loss of some 0.4 cubic miles (1.67 cubic kilometers) of ice (1.5 trillion liters) of water.

• Cruise ships used to nose close to the edge of the glacier in Prince William Sound and watch icebergs break off the glacier and float away

• In 1983 it started to retreat. The cruise ships anchor in the same spot and are now 27 kilometres from the glacier wall - unable to move closer through melting icebergs and rocky shoals

C Forests are dying

• Drunken forest is a recent phenomenon. Large areas of forest are turning grey as they drown. The tree roots are loosened and they are tilted at odd angles

• One third to half of Alaska’s white spruce have died in the last 15 years. Many drowned but more destroyed by exploding populations of Spruce bark beetles moving ever north

D THE COST OF ROAD REPAIRS IS INCREASING

• Stretches of highway have ‘waves’ in them and driving is dangerous as the roads have cracked and broken

• Maintenance crews repair and re-repair the same stretches

E THERMOKARSTS ARE APPEARING IN GREATER NUMBERS

• When permafrost melts there are pockets of solid ice trapped in it. When this melts the ground collapses and creates holes at the surface (perhaps 2.5 metres and up deep)

• Permafrost is moving northward. It has already moved 120 kilometres in some areas. Predictions of 500 kilometres eventually

F RECORDS

• University of Alaska records show an increase in the average temperature of Alaska, Siberia and northwestern Canada of 5 degrees F.

• 30 years ago the temperature of Fairbanks reached 25 C for only one week in the summer. Now there are about three weeks over 25 C

• Winter temperatures in Fairbanks frequently went below minus 40. In the last 20 years the number of days below minus 40 have dropped substantially compared with the previous 30 years

Permafrost

Settlement• Newtok• Erosion has made Newtok an island, caught between the ever

widening Ninglick River and a slough to the north.• The village is below sea level, and sinking.• Boardwalks squish into the spring muck. Human waste,

collected in “honey buckets” that many residents use for toilets, is often dumped within eyeshot in a village where no point is more than a five-minute walk from any other. The ragged wooden houses have to be adjusted regularly to level them on the shifting soil.

• “I don’t want to live in permafrost no more,” said Frank Tommy, 47, standing beside gutted geese and seal meat drying on a wooden rack outside his mother’s house. “It’s too muddy. Everything is crooked around here.”

• The permanently frozen subsoil, known as permafrost, upon which Newtok and so many other Native Alaskan villages rest, is melting, yielding to warming air temperatures and a warming ocean.

• Sea ice that would normally protect coastal villages is forming later in the year, allowing fall storms to pound away at the shoreline.

• Studies say Newtok could be washed away within a decade. Along with the villages of Shishmaref and Kivalina farther to the north, it has been the hardest hit of about 180 Alaska villages that suffer some degree of erosion.

• Some villages plan to hunker down behind sea walls built or planned by the Army Corps of Engineers, at least for now.

• Shishmaref is situated on a barrier island no wider than 1/4 mile, and 3 miles in length.

• The island is comprised of fine sand deposits and permafrost that is vulnerable to erosion.

• The community has experienced erosion of its north shoreline an average of 3-5 feet per year, except for the storms of: November 9&10, 1973, October 4, 1997, and October 7, 2001 where extensive erosion in highly vulnerable areas was as much as 125’ horizontal distance.

• The community is most vulnerable when tidal high water is combined with intense wave action of the Chukchi Sea during storms.

• Erosion has been heightened by continual degradation of permafrost. An average high tide is 3 feet above the normal tide, during storms; the wave action can increase the high tide by 3 feet, which causes the waves to crest over the bluff.

MINOR SWING?

• Atmospheric changes in circulation have occurred bringing warmer air from the Pacific so this might be a minor change in the weather

ADVANTAGES• Increase in tourism with the longer summers

• Shipping by sea easier and an open-water sea route to Europe from Alaska could open up (problem of jurisdiction – USA vs Canada

• More offshore drilling for oil as sea ice contracts

• Fisheries could expand with warmer water

DISADVANTAGES

• Forests are being destroyed. The change period is the problem as the forests move northward.

• Other forests should move north but in Alaska the only environment is the Gulf of Alaska

• Permafrost is melting - roads, buildings, agricultural land

• Glaciers are retreating and agriculture is starving for water

• If this is global warming or a sign of it– emissions of heat trapping gases such as carbon

dioxide. Created by the burning of fossil fuels (coal, oil, natural gas)

– Less ice and snow so less reflection back of heat

• Melting Arctic Ocean Raises Threat of ‘Methane Time Bomb’

•

• Scientists have long believed that thawing permafrost in Arctic soils could release huge amounts of methane, a potent greenhouse gas.

• methane is beginning to bubble up from the bottom of the fast-melting Arctic Ocean.

QUESTION OF PREDICTION

• Can we predict•

– supply of resources

– impacts of changes

– human response

• ?

LIMITS TO GROWTH

• Report produced by the Club of Rome

• Basic assumptions of the report– The enormous economic growth of the 50’s and

60’s could continue into the future– This growth would occur in both the North and

South parts of the planet

WORLD POPULATION

• Demonstration of exponential growth

• Assumption of ‘current’ growth rates

• Limits to growth p.41

ECONOMIC GROWTH RATES

• Spectre of exponential rates here as well

• Note the increasing gap between ‘have’ and ‘have nots’

• Limits to Growth p. 47

LIMIT - FOOD AND ARABLE LAND

LIMIT - NON-RENEWABLE RESOURCES

• Chromium as an example

• Note lifetime of resource depends on rate of use

• dependent on demand

• Limits to Growth p. 70

LIMIT - POLLUTION

• Again the problem of exponential growth linked to population increase and increasing industrialisation

• Limits to growth p. 79

RESULT - WORLD STANDARD RUN

• Assumption of no change

• Resource shortage hits as other factors grow

• Limits to Growth p. 129