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Global Environmental Problems - An overview
Transcript of Global Environmental Problems - An overview
16266 SUSTAINABLE URBAN DESIGN & DEVELOPMENT
UNDERSTANDING THE FUNDAMENTALS
THE RUNNING SHEET FOR TODAY...
Dr. Pernille Christensen
What are 'Global Environmental Problems'?
THE SILENT SPRING
CLIMATE CHANGE AND GLOBAL WARMING
CLIMATE CHANGE - OR CLIMATE CHAOS?
Limits to growth – can we act fast enough to avert environmental decline and economic collapse?
What about Malthus? -
1798: An Essay on the Principle of Population
Herbert Spencer – survival of the fittest
Is capitalism sustainable?
Is ‘growth’ going to be the death of us?
Are we capable of transitioning from growth to ecological equilibrium?
Some questions to ponder …
Debate on whether we should pursue economic growth at all.
Category 3 - Natural Sinks
Agricultural soils management
Category 2 -
Decarbonisation of Electricity & Fuels
Substituting gas for coal
Storage of carbon captured in:
Category 1 - Efficiency& Conservation
Improved fuel economy
Reduced reliance on cars
More efficient buildings (reduce mid century emissions by 25%)
Improved power plant efficiency
Focus on carbon but also targets for methane, N20.
Stabilisation means holding current levels for the next 50 years.
What do we mean ‘solving’ the carbon problem?
Climate change and global warming
Ozone depletion, the gulf stream, climate zone, global warming – what do you believe?
Pacala and Socolow (2004) proposed ‘wedges’ strategy – considered how we might stabilise CO2 emissions.
View that 500ppm (+- 50) is the upper limit (2x pre industrial levels).
Suggested nuclear is an option we must consider
Use of biofuels – but could affect food supply to poorest nations.
Monbiot (2007) – 90% reductions required to restrict cc to +2 degrees.
Vanishing artic sea ice, migrating and disappearing species,
Cows eat grass and belch and fart methane
Methane is a GHG – how potent is it?
Also pigs, horses, sheep, goats, camels ….
Termites – a typical mound emits 5l / minute
A bulldozed mound can be rebuilt in hours
Estimated .5 ton of termites per person
Rice paddies are oxygen-less – rice production is growing and related to population growth
And then there is landfill …………….
Svante Arrhenius - CO2 recognised as a GHG late 19th Century
Late 1950s realised human related CO2 cannot be absorbed by oceans
Rachel Carson, The Silent Spring (1962)
Warming caused by fossil fuel consumption, deforestation.
Al Gore (2006) – An Inconvenient Truth - increased sense of urgency
IPCC (2007) – consensus view of scientific community, conservative - oceans risen 8m and temp increase 1.3 degrees C. (www.ipcc.ch)
Provide 85% of worlds commercial energy – oil 40%
Most consumed in cities
Kyoto Protocol 1997 – agreed to cut CO2 by 5% to 2010
Kyoto Protocol 2nd commitment - agreed to cut CO2 by 5% below 2000 by 2020.
How much is needed to ‘halt’ global warming?
How can we reduce consumption? How does the built environment contribute to energy usage?
GHG Emissions & Energy
The Nature of Solid Waste Has Changed ...
Water often drawn from rivers miles away – destroying habitats
400l/day London, US 600l/day – Australia?
Process – percolation through sand beds, chlorination – switch to bottled water – issues there are?
Sewage often flushed into rivers or the ocean
Water and sewage
Vienna increases its weight by 25000 tons per day (pop. 1.6M)
London water table is undrinkable - toxins have accumulated over 200 years, but much of the pollution is a build up of heavy metals over the last 50 years.
Don’t consider origin or destination of wastes – where does it typically end up?
What sort of cities should we have?
Resource Use ...
‘The flow of natural resources into cities and wastes out of them represents one of the largest challenges to urban sustainability’.
What's the percentage of Australians living in cities? How does it compare elsewhere?
Giradet – existing cities operate a
of flows whereas we need to change to a ‘closed loop’ and emulate ecosystems.
What is a linear system? vs. What is a closed loop?
Utopia is ... Ecotopia is ...
Dystopia is ...
A futurist who believes that continued progress and provision of material items for mankind can be met by similarly continued advances in technology.
Believe that there is enough matter and energy on the Earth to provide for the ever-rising population of the world.
Abundance of matter and energy in space would appear to
give humanity almost unlimited room for growth.
How does this sit with Malthus?
The term for some ‘environmentalists’
Alarmist and pessimistic
Issues of birth control – limiting family size
Which countries can you think that have adopted limits to family size? Has it been successful?
What about countries where there is now an ageing populations - fewer younger people will have to support a large aged population?
Population ... it’s complex
Factors likely to limit growth were:
Population, agricultural production, natural resources, industrial production and pollution.
An economic study, not an environmental one
Social change is necessary
Technological innovation will not deliver solution
Perspectives, Problems and Models (from the Limits to Growth), Meadows, D et al, pp 48-52
The Metabolism of Cities, Girardet, H. pp 158-164
The End of Nature, McKibben, B, pp 64-71
Stabilization Wedges: Solving the Climate Problem for the next Fifty Years with Current Technologies, Pacala, S and Socolow, R, pp 173-180
Were the estimates accurate?
Ehrlich under-estimated what?
Just like? Malthus in the 1830s
"The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate ..." (1972)
Only looked at a few of the global environmental problems:
The end of nature and the silent spring
Climate change and global warming
They are complex and inter-related, requiring deep thought and significant philosophical changes.
THE BIG PICTURE
COWS, TERMITES & RICE PADDIES
Both the type of waste AND the amount ...
From Pottery and discarded metals to non-degradable plastics and spent nuclear waste.
30% of landfill material is putrescent (will rot and biodegrade) - there are better (and safer) ways of disposing of this type of waste
Rethink waste disposal – landfill taxes have increased
Energy from landfill waste is an option…
POPULATION TIME BOMB - Ehrlich
Sara J Wilkinson SUDD 16266 S2 2012
‘One small step for man, one giant leap for mankind’
- Neil Armstrong.
Apollo Space Missions
"The Limits to Growth" - 1972 - Meadows, D. H. et al.
Linear System vs. Closed Loop
MALTHUS - 1798
Pacala, S and Socolow, R, pp 173-180
Pacala, S and Socolow, R, pp 173-180
The choice is between
action and delay
None of the options is a pipe dream
Each could be scaled up to an industrial scale to provide at least one wedge.