Transcript The Need for Action - evidence for global warming, hope for solutions

The Need for Action evidence for global warming,
hope for solutions
Geoff Davies
Visiting Fellow
Earth Sciences, ANU
Author: Economia
Is global warming happening?
• Yes.
Is global warming happening?
• Yes.
Is global warming still
happening?
•
•
•
Yes, it’s the
long-term
trend.
Note pauses
1980s,
1990s.
2010 equal
warmestever, so far.
What about cooling 1940-1970?
Mainly in
northern
hemisphere
Text
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• Due to
•
•
industrial soot and dust
cooling North Atlantic ocean
Arctic sea ice, to September
2007
Previous minima
Decline of Arctic sea ice (area)
Decline of Arctic sea ice (volume)
Are we causing global warming?
• Consistent with predictions from 20-30 years
ago
• Many lines of evidence
• well-established physics (100+ years)
• measured patterns of warmth in atmosphere
• the past
• models - disputed but consistent
Patterns of warmth:
Indications from the past
• e.g. temperature and CO2 variations in
during ice ages
CO2
Temperature
Indications from the past
• Collective
estimates from
•
ice ages
• volcanic
eruptions
•
past warm
episodes
•
sediment
records
Result: 3-4°C (or more) per doubling of
Consequences? Many.
Consequences? Many.
• Ecosystems
• Complex interactions:
• different species respond differently
• some decline - extinctions
• some increase - plagues
• trees migrate slower than birds ecosystems ripped apart
• Total effects impossible to predict
Consequences? Many.
• Sea level
Is there any hope?
• Yes • with good policies, cost to economy small
(<1% GDP)
• eliminating waste is the quickest, most
cost-effective option - start tomorrow
• many technologies available already
• We can accept remaining difficulties as a
challenge, not a reason to dither
Cost of 60% emissions reduction:
9 months longer to double GDP
No action
Early action
Steve Hatfield-Dodds, CSIRO
Reducing waste
•
Available now at zero or moderate cost:
•
Building energy efficiency: quadruple
•
Vehicle fuel efficiency: double
•
Household electricity use: one quarter
•
Water efficiency double (or more)
•
...
Eliminating waste
Redefine waste: as nutrient
(Cradle-to-cradle design)
Carpet nutrient
Battery nutrient
•
•
Interface Carpet Inc. - efficiency gains
Broadloom to tiles: x5
Recyclable polymer:
•
•
•
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2/3 the material: x1.5
4 times as durable: x4
Total gain x30 (97% material reduction)
After 4 years:
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•
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Revenues doubled
Employment nearly doubled
Profits tripled!
The second industrial
revolution
•
Waste is nutrient
•
(Organic) growth is good
•
Survive on energy income
•
Diversity is resilience
A factory like a forest?