AVOID is funded by the Department of Energy and Climate Change and the Department for Environment, Food and Rural Affairs

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,

ReadingPam Berry, Environmental Change Institute, University of Oxford, Dyson Perrins

Building, South Parks Road, Oxford OX1 3QYLynn 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, JapanRobert Nicholls, School of Civil Engineering and the Environment and Tyndall

Centre, University of Southampton, Southampton SO17 1BJJesse O’Hanley, Kent Business School, University of Kent, Canterbury CT2 7PETim Osborn and Sarah Raper, Climatic Research Unit, School of Environmental

Sciences, University of East Anglia, Norwich NR4 7TJ

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

Probability …

Year A1B 2016.R

(2%H, 4%L, 5%L)

2030.R

(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 analysis showed that …

Temperature implications

Jason Lowe’s work told us:

• Under A1B temperatures are likely to reach 3-4C

• 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: Avoidingesclating 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 : Avoidingincreases 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.

WATER water resources coastal flood fluvial flood

FOOD crop suitability crop productivity

ENVIRONMENTsoil carbon, ecosystem productivity biodiversity HEALTH INFRASTRUCTURE heat effects heating/cooling needs

Sectors and impacts indicators

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.

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…

% of impacts avoided

0

10

20

30

40

50

60

70

80

Incr

ease

dw

ater

scar

city

Flu

vial

floo

dris

k

Coa

stal

floo

dris

k

Coa

stal

man

grov

e

Dec

reas

edcr

opsu

itabi

lity

Soy

bean

prod

uctiv

ity

Coo

ling

requ

irem

ents

% o

f im

pa

cts

av

oid

ed

2016-5-L

% of impacts avoided

0

10

20

30

40

50

60

70

80

Incr

ease

dw

ater

scar

city

Flu

vial

floo

dris

k

Coa

stal

floo

dris

k

Coa

stal

man

grov

e

Dec

reas

edcr

opsu

itabi

lity

Soy

bean

prod

uctiv

ity

Coo

ling

requ

irem

ents

% o

f im

pa

cts

av

oid

ed

2016-5-L

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

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

Population exposed to increasedwater resources stress

Increase in water resources stress

0

2

4

6

8

10

12

14

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

% o

f g

lob

al p

op

ula

tio

n

A1b A1b-2016-2-H A1b-2016-4-L

A1b-2016-5-L A1b-2030-2-H A1b-2030-5-L

… but even the most stringent mitigation will not avoid all impacts

Area with decrease in crop suitability

HadCM3

Decrease in crop suitability

0

10

20

30

40

50

60

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

% o

f cr

op

lan

d

A1b A1b-2016-2-H A1b-2016-4-L A1b-2016-5-L

A1b-2030-2-H A1b-2030-5-L

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 fluvial flood risk

0

50

100

150

200

250

300

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

Year

% c

hang

e in

floo

d ri

sk

A1b 2016-2-H 2016-4-L 2016-5-L

2030-5-L 2030-2-H

Some benefits of mitigation policy are realised by the 2050s. Benefits continue to increase in the second half of the century.

Area with decrease in crop suitability

HadCM3

Decrease in crop suitability

0

10

20

30

40

50

60

2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100

% o

f cr

op

lan

d

A1b A1b-2016-2-H A1b-2016-4-L A1b-2016-5-L

A1b-2030-2-H A1b-2030-5-L

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 hazardA1B 2100

%

Percentage of flood-prone population exposed to an increase in flood hazard2016.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.

Contact Jolene Cook (jolene.cook@decc.gsi.gov.uk) for more information on how to join us as a stakeholder

Contact Rachel Warren(r.warren@uea.ac.uk)for more information about work stream 1

Contact Jason Lowe (avoid-chiefsci@metoffice.gov.uk) 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

Thank you for your attention…