Download Climate-Economy Modelling

Dr. Richard S.J. Tol
• http://www.unihamburg.de/Wiss/
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ty/tol.html
Reducing Vulnerability to
Climate Change:
Development v Mitigation
Richard S.J. Tol
Hamburg, Vrije and Carnegie
Mellon Universities
Reducing Vulnerability to
Climate Change
• Many, most notably Tom Schelling, have
argued that greenhouse gas emission
reduction is a subsidy to the children and
grandchildren of the poor
• Emissions are concentrated in the rich
countries, negative impacts in the poor
countries
• If we want to help the poor, are there not
better ways than through emission
reduction?
Reducing Vulnerability -2
• If we want to help the poor, are there not
better ways than through emission
reduction?
• Probably, but the separation of climate
change from global change from
sustainable development from development
has left us empty handed
• There are, as yet, no models or other tools
that tell us that emission reduction will
bring us X, tha development aid will bring
Y, and that Y>X
Climate change induced vector borne mortality
800,000
number of deaths
700,000
600,000
500,000
400,000
300,000
200,000
Frozen baseline
Low-FB
High-FB
Population growth
Economic growth
Africanism
Communism
Vaccin
100,000
0
2000 2010 2020 2030 2040 2050 2060 2070 2080 2090 2100
year
% change in cumulative mortality
4
3
Climate change and economic growth reduced
2
1
Kyoto
0
-1
0.0
0.5
1.0
1.5
2.0
2.5
-2
-3
-4
Climate change only reduced
% annual emission reduction in OECD
3.0
Outline
• Introduction and motivation
• Actually, I will not answer the question
asked (because I do not have a general
model of development) but rather wonder
whether development reduces vulnerability
to climate change more than does
mitigation
• The FUND model
• Results
• Discussion
FUND2.4
• The Climate Framework for Uncertainty,
Negotiation and Distribution (FUND) is an
integrated assessment model of climate
change; current version is 2.4
• It links population, technology, economic
activity, emissions, concentrations, climate,
sea level, impacts
• It runs from 1950 to 2200, for 9 major
world regions
• Everything is fairly standard, except the
impacts module
FUND2.4: Impacts
• Agricultural impacts rise and fall with
climate, rise with CO2, fall with per capita
income
• Energy impacts rise or fall with climate,
fall with per capita income and technology
• Water impacts rise or fall with climate, fall
with per capita income and technology
• Coastal impacts rise with sea level, fall
with per capita income, but coastal
wetlands counteract this
FUND2.4: Impacts -2
• Cardiovascular and respiratory diseases
rise or fall with climate, rise with
urbanisation, rise with per capita income
(inner city poverty is excluded)
• Vector-borne diseases rise or fall with
climate, fall with per capita income
• Ecosystem impact rise with climate, rise
with per capita income, rise with
biodiversity loss
• How to add this all up?
Trade-offs
• Estimate the marginal costs of greenhouse
gas emissions, that is, the net present
value of the difference in damage between
two scenarios with slightly different
emissions, expressed in $/tC
• Estimate the marginal benefits of
development, that is, the net present value
to the difference in damage between two
scenarios with slightly different initial
incomes, expressed in $/$
• Calculate the ratio
Marginal Costs and Benefits
6
4
-4
-6
A
FR
CP
A
EA
S&
S
LA
M
E
fS
U
CE
E&
O
EC
D
-E
O
EC
D
-A
O
EC
D
ld
-2
-P
0
W
or
$/tC, $/$
2
Climate Costs
Development Benefits
infectious disease+
cooling energyabove 65+
heating energy+
urban population+
base
urban populationheating energyagriculturewater resourcesabove 65agriculture+
water resources+
infectious diseasecooling energy+
1.50
1.60
1.70
1.80
return on development aid
1.90
2.00
IS92f
SRES A2
IS92a
FUND
IS92d
SRES B2
SRES B1
SRES A1G
SRES A1C
SRES A1T
Growth rate
SRES A1
Return on aid
0.0
1.0
2.0
3.0
4.0
return on development aid, average growth rate
5.0
vector 1.5
cooling 1.5
cardioresp 0.5
water 1.5
agriculture 0.5
heating 1.5
base
heating 0.5
agriculture 1.5
water 0.5
cardioresp 1.5
cooling 0.5
vector 0.5
0.75
1.00
1.25
1.50
1.75
2.00
return on development aid
2.25
2.50
2.75
Discussion
• Greenhouse gas emission reduction seems
to be a better way of reducing
vulnerability to climate change than is
accelerating development
• Note that I used optimistic assumptions on
both sides, ignoring trade effects and
assuming effective aid
• The exceptions are the very poor and
vector-borne diseases, read malaria in
Africa – in that case, development reduces
vulnerability faster than does mitigation
(while there are other benefits as well)
More Discussion
• The conclusion seems to be that we should
relocate part of the climate budget
towards health care in Africa, but not
development in general
• Of course, this has to be tested further –
particularly the latter half of the
conclusion needs to be assessed with a
wider model of development and
environment