Transcript Slide 1

AVOID Work Stream 1: THE ECONOMICS AND
CLIMATE CHANGE IMPACTS OF GREENHOUSE GAS
EMISSION PATHWAYS: COMPARISON BETWEEN
BASELINE & POLICY EMISSION SCENARIOS
Rachel Warren (Lead WS1 and CIAS), Tyndall Centre, School of Environmental
Sciences, University of East Anglia, Norwich NR4 7TJ
Nigel Arnell (QUEST-GSI), Walker Institute, University of Reading, Earley Gate,
Reading
Pam Berry, Environmental Change Institute, University of Oxford, Dyson Perrins
Building, South Parks Road, Oxford OX1 3QY
Lynn Dicks and Serban Scriecru, 4CMR, Dept of Land Economy, University of
Cambridge, 19 Silver St., Cambridge
Chris Hope, 4 Judge Business School, University of Cambridge
Jason Lowe, Met Office Hadley Centre (Reading Unit), Department of
Meteorology, University of Reading, Reading, RG6 6BB
Kenichi Matsumoto and Toshihiko Masui Climate Policy Assessment Section,
Center for Global Environmental Research, National Institute for
Environmental Studies, 16-2, Onogawa, Tsukuba, Ibaraki, 305-8506, Japan
Robert Nicholls, School of Civil Engineering and the Environment and Tyndall
Centre, University of Southampton, Southampton SO17 1BJ
Jesse O’Hanley, Kent Business School, University of Kent, Canterbury CT2 7PE
Tim Osborn and Sarah Raper, Climatic Research Unit, School of Environmental
Sciences, University of East Anglia, Norwich NR4 7TJ
AVOID is funded by the Department of Energy and Climate Change and the Department for Environment, Food and Rural Affairs
The modelling approach
• Consistent climate scenarios
• IPCC AR4 runs pattern-scaled
to AVOID global temperature
change
• Monthly climate changes from
downscaling (e.g. precipitation,
temperature)
• Consistent socio-economic
scenarios
• A1B baseline – median
temperature rise of 4°C in 2100
above pre-industrial levels
• Global-scale impacts models
• Applied tools produced by
QUEST-gsi and CIAS
The Scenarios
• Emission scenarios: varied year in which
emissions peak globally, the rate of
emission reduction (R), and the minimum
level to which emissions are eventually
reduced (H or L).
• Focused on 2015-2044 (centred on 2030)
2035-2064 (centred on 2050)
2070-2099 (centred on 2085)
Scenarios: A1B, and policy scenarios
• 2030.R2.H, 2030.R5.L,
• 2016.R2.H, 2016.R4.L and 2016.R.Low
Temperature implications: Jason Lowe’s
analysis showed that …
Probability Year
…
A1B
2016.R
2030.R
(2%H,
4%L, 5%L)
(2%H,
5%L)
of
remaining
below 2
degrees
2100
1%
30, 43,
45%
7, 17%
of
remaining
below 3
degrees
2100
1%
87, 91,
91%
63, 76%
of
remaining
below 4
degrees
2100
46%
98, 99,
99%
93, 96%
Temperature implications
Jason Lowe’s work told us:
• Under A1B temperatures are likely to reach 34C
• 2030 peaking insufficient for 2C and have
chance of 1 in 3 to 4 of exceeding 3C
• 2016 targets effective at avoiding 3C, chance
of exceeding falls to 1 in 10
• Only most stringent R=5% 2016 scenario has
45% chance to meet 2C target
• All avoid temperatures reaching 4 degrees
with high confidence (>=98%) except for 2030
2% L which leaves a 7% chance of more than
4C.
Key benefit: Avoiding
esclating risks of breach of tipping
points
• Since under A1B temperatures are likely to reach 3-4C
breaching of several tipping points in the earth system is
likely.
• This would raise temperatures above 4C since many act as
feedbacks and are not included in climate models
presently
• Breaching range of several key tipping points may occur at
3C
• 2016 scenarios effective at avoiding entering this range,
chance of exceeding falls to 1 in 10
• 2030 scenarios only reduce it to 1 in 3 or4
Key benefit : Avoiding
increases in extreme weather
• Most immediately felt climate change impacts will be those
due to increased extreme weather and its impacts upon
infrastructure, agriculture and ecosystems
• May be as/more important than climate
impacts simulated for continuous warming
• Fluvial & coastal flood only included here
• A related study shows drought frequency
in Europe can be greatly reduced by
stabilization at 450 ppm CO2-e.
Sectors and impacts indicators
WATER
water resources
coastal flood
FOOD crop suitability
ENVIRONMENT
soil carbon,
ecosystem productivity
biodiversity
fluvial flood
crop productivity
HEALTH
INFRASTRUCTURE
heat effects heating/cooling needs
Impacts simulation methods
• Off-line, spatially-explicit (usually 0.5x0.5o)
impacts models, with indicators aggregated to
larger geographic regions
• Indicators characterise exposure to impact,
not estimated actual impact
= “adaptation+residual impact”
• Indicators show exposure relative to the
situation at the same time without climate
change
Key findings
• Strong mitigation action to limit temperature rise
to below 2°C avoids many of the climate impacts.
• …but not all the impacts are avoided.
• Some benefits of mitigation policy are realised by
the 2050s. Benefits continue to increase in the
second half of the century.
• There is considerable regional variation in
avoided impacts.
Key findings
• Strong mitigation action to limit temperature rise
to below 2°C avoids many of the climate impacts.
• …but not all the impacts are avoided.
• Some benefits of mitigation policy are realised by
the 2050s. Benefits continue to increase in the
second half of the century.
• There is considerable regional variation in
avoided impacts.
Strong action to limit to below 2°C avoid a
large amount of the climate impacts that
would otherwise accrue by the 2080s…
80
70
60
50
40
30
20
Cooling
requirements
Soybean
productivity
Decreased
crop
suitability
Coastal
mangrove
Coastal flood
risk
Fluvial flood
risk
10
0
Increased
water
scarcity
% of impacts avoided
% of impacts avoided
2016-5-L
AVOID is funded by the Department of Energy and Climate Change and the Department for Environment, Food and Rural Affairs
Strong action to limit to below 2°C avoid a
large amount of the climate impacts that
would otherwise accrue by the 2080s…
…… but even the most stringent mitigation
will not avoid all impacts
80
70
60
50
40
30
20
2016-5-L
Cooling
requirements
Soybean
productivity
Decreased
crop
suitability
Coastal
mangrove
Coastal flood
risk
Fluvial flood
risk
10
0
Increased
water
scarcity
% of impacts avoided
% of impacts avoided
… but even the most stringent mitigation will
not avoid all impacts
Increase
in water
resources
stress
Population
exposed
to increased
% of global population
water resources stress
14
12
10
8
6
4
2
0
2000
2010
2020
2030
2040
2050 2060
2070
2080
A1b
A1b-2016-2-H
A1b-2016-4-L
A1b-2016-5-L
A1b-2030-2-H
A1b-2030-5-L
2090
2100
AVOID is funded by the Department of Energy and Climate Change and the Department for Environment, Food and Rural Affairs
… but even the most stringent
mitigation will not avoid all impacts
Decrease in crop suitability
60
% of cropland
50
40
30
20
10
0
2000
2010
2020
2030
2040
A1b
A1b-2016-2-H
A1b-2030-2-H
A1b-2030-5-L
2050
2060
2070
A1b-2016-4-L
Area with decrease in crop suitability
HadCM3
2080
2090
A1b-2016-5-L
2100
Key findings
• Strong mitigation action to limit temperature rise
to below 2°C avoids many of the climate impacts.
• …but not all the impacts are avoided.
• Some benefits of mitigation policy are realised by
the 2050s. Benefits continue to increase in the
second half to the century.
• There is considerable regional variation in
avoided impacts.
Some benefits of mitigation policy are
realised by the 2050s. Benefits continue to
increase in the second half of the century.
% change in flood risk
Change in fluvial flood risk
300
250
200
150
100
50
0
2000
2010
2020 2030
2040
2050
2060
2070 2080
2090
Year
A1b
2016-2-H
2030-5-L
2030-2-H
2016-4-L
2016-5-L
2100
Some benefits of mitigation policy are
realised by the 2050s. Benefits continue to
increase in the second half of the century.
Decrease in crop suitability
60
% of cropland
50
40
30
20
10
0
2000
2010
2020
2030
2040
A1b
A1b-2016-2-H
A1b-2030-2-H
A1b-2030-5-L
2050
2060
2070
A1b-2016-4-L
Area with decrease in crop suitability
HadCM3
2080
2090
A1b-2016-5-L
2100
Key findings
• Strong mitigation action to limit temperature rise
to below 2°C avoids many of the climate impacts.
• …but not all the impacts are avoided.
• Some benefits of mitigation policy are realised by
the 2050s. Benefits continue to increase in the
second half to the century.
• There is considerable regional variation in
avoided impacts.
Percentage of flood-prone population
exposed to an increase in flood hazard
A1B 2100
%
Percentage of flood-prone population
exposed to an increase in flood hazard
2016.R5.L 2100
%
Sources of uncertainty
Estimates of avoided impacts are uncertain due to
uncertainty in:
1. global mean temperature change
2. regional pattern of change in climate
3. socio-economic conditions
Key findings
• Strong mitigation action to limit temperature rise
to below 2°C avoids many of the climate impacts.
• …but not all the impacts are avoided.
• Some benefits of mitigation policy are realised by
the 2050s. Benefits continue to increase in the
second half of the century.
• There is considerable regional variation in
avoided impacts.
Thank you for your attention…
Contact Jolene Cook
([email protected])
for more information on how to join us as a
stakeholder
Contact Rachel Warren
([email protected])
for more information about work stream 1
Contact Jason Lowe
([email protected])
for more information on the scientific content
of AVOID
www.avoid.uk.net
AVOID is funded by the Department of Energy and Climate Change and the Department for Environment, Food and Rural Affairs