Transcript Engaging with the Future: State Farm II Said Business School 24

Valuing Our Life Support Systems
Savoy Place, 29 April 2009
IMPACTS ON THE
ENVIRONMENT:
CLIMATE CHANGE
Robert M May
Zoology Department
Oxford OX1 3PS, UK
Humanity’s Impacts
Over the past century and a half:
• the human population has increased x 7
• the global average energy use per person
has increased x 7
• That is, overall energy use has
increased roughly fifty-fold
Fig. 2: ECOLOGICAL FOOTPRINT AND BIOCAPACITY BY REGION, 2003 (After Ref. 5)
STATEMENT BY SCIENCE ACADEMIES
OF THE G8, plus CHINA, INDIA, BRAZIL
Calls on G8 countries to “identify costeffective steps that can be taken now to
contribute to substantial and long-term
reduction in net global greenhouse gas
emission [and] recognise that delayed
action will increase the risk of adverse
environmental effects and will likely incur a
greater cost”
Building a Low-Carbon Economy –
The UK's Contribution to Tackling
Climate Change
www.theccc.org.uk
1. The 2050 target
(i)
Required global emissions reduction
(ii)
Appropriate UK contribution
(iii)
Technologies for meeting required reductions
(i) Required global emissions reduction
What’s changed?
• Advances in science
• Actual emissions higher
than forecast
Assessment of damage
Decision rule
• keep temperature
change close to 2°C
• and probability of 4°C
increase at very low
level (less than 1%)
•
•
Global trajectories
considered
Early or later peak
(2015 vs. 2030)
3%/4% annual
emissions reduction
•
•
Required global
emissions reduction
of 50%
20-24 GtCO2e
emissions in 2050
8-10 GtCO2e in
2100
(ii) Appropriate UK contribution
50% global reduction
Burden share
• Alternative methodologies (contract and
converge, intensity convergence, triptych
etc.)
• Equal per capita emissions:
̶
20-24 GtCO2e total at global level in
2050
̶
Implies 2.1-2.6 tCO2e per capita
All GHGs
2.1-2.6 CO2e per
capita gives a UK
reduction of at least
80% in 2050
Aviation and
shipping included
Conclusion
•
80% cut in GHG emission by 2050 relative to 1990: all
GHGs, aviation and shipping included
•
Unilateral 34% cut in GHGs by 2020 relative to 1990 (21%
relative to 2005)
•
42% cut in GHGs by 2020 relative to 1990 (31% relative to
2005) after global deal is achieved
•
34% cut predominantly through domestic emissions
reduction
•
42% through domestic emissions reduction and credit
purchase
•
2020 cost less than 1% of GDP
Climate Change - a Multiplier
for Instability
Recent Conflicts
Water scarcity Demography Crop decline
Hunger
Coastal risk