Apresentação utilizada no workshop “Adaptação à Mudança do Clima no Brasil em 2040: cenários e alternativas”, aborda questões relevantes no planejamento da adaptação às alterações climáticas. Autor: Gordon Hughes. Veja mais em: http://ow.ly/sN0hw

1. Key issues in planning
adaptation to climate change
Gordon Hughes
University of Edinburgh
16th December 2013

2. Context - different kinds of adaptation
Adaptation will occur – the question is how
Planned adaptation
Modify assets to allow for expected (but not
certain) climate conditions
Initial investment to reduce future O&M costs
Responsive adaptation
Build assets for current climate conditions
Upgrade or replace them as the climate changes
Higher future costs but less risk of mistakes
2

3. Climate proofing – the standard model
Core engineering approach
Project investment & O&M spending to 2050
Estimate increase in unit costs to protect assets
against climate change over their life
Calculate marginal cost of climate protection
Questions to address
How is the future climate defined?
How far into the future should we look?
What are the climate stress-response models?
3

4. What are the most important climate
stresses?
Roads & transport
Surface integrity – (max) pavement temperature
Flood damage – (max) 3-day precipitation
Buildings
Ventilation – moisture & humidity
Roofs & structures – precipitation & wind speed
Urban infrastructure
Storm water – 3-day precipitation
4

5. Allowing for climate uncertainty
Substantial variation in key climate variables
across GCMs (climate scenarios)
How should design standards be set?
Average over all scenarios
Worst outcome or 95th percentile of scenarios
Robust scenario allowing for uncertainty
Responsive adaptation may be viewed as a
“wait and act” strategy
5

6. 99th pctile of daily maximum temperature (deg C)
32
34
36
38
40
42
Example 1: heat waves in Macedonia
(99th percentile of daily max temp)
1980
2010
2030
2050
2070
2090
6

7. 100
Maximum 3-day rainfall (mm)
120
140
160
180
Example 2: flood exposure in Macedonia
(max 3-day precipitation)
1980
2010
2030
2050
2070
2090
7

8. The planning horizon: how far ahead
should we look?
Trade-off between initial cost and future O&M
Arises even under certainty (perfect foresight)
Depends on (a) the cost curve for adaptation, and
(b) rate of change in key climate variables
Optimal planning horizon > 20 years is very
unusual
Higher discount rate -> shorter planning horizon
More uncertainty -> shorter planning horizon
8

9. For the Balkans, a planning horizon less
than or equal to 20 years is adequate
Discount rate
A. All countries
0%
2%
5%
8%
10%
B. Macedonia
0%
2%
5%
8%
10%
0
Planning horizon (years)
10
20
30
40
0
0
11
51
82
3
11
38
37
6
82
77
39
0
0
3
0
0
0
0
0
0
0
0
0
0
0
0
3
8
0
1
2
5
0
7
7
6
0
0
1
0
0
0
0
0
0
0
0
0
9

10. Using perfect foresight to identify priority
sectors and regions
Use distribution of the costs of adaptation
under perfect foresight to focus analysis
Where, when & in which sectors are the costs of
adaptation significant relative to base spending?
How sensitive are the relative costs to variations
across climate scenarios?
What is the contribution of existing infrastructure
to the costs of adaptation?
This will decline over time but focuses attention on
upgrading existing assets as well as building new ones
10

11. Cost of adaptation under perfect foresight
(Average over GCMs, % of baseline spending)
Country
Albania
Bulgaria
Bosnia
Greece
Croatia
Kosovo
Macedonia
Montenegro
Romania
Serbia
Slovenia
Power &
phones
0.6%
0.6%
0.6%
0.8%
0.6%
0.6%
0.5%
0.6%
0.6%
0.6%
0.7%
Water &
sewers
0.2%
0.4%
0.3%
0.5%
0.3%
0.3%
0.3%
0.3%
0.3%
0.3%
0.3%
Roads
7.1%
3.2%
8.5%
22.6%
25.2%
21.4%
2.4%
22.3%
13.3%
4.0%
10.6%
Other
transport
3.7%
2.9%
5.4%
2.4%
5.3%
2.9%
2.4%
4.2%
4.5%
3.8%
4.6%
Health &
schools
0.9%
1.0%
1.0%
2.1%
1.0%
0.9%
0.9%
0.9%
1.0%
1.0%
1.1%
Urban
Housing
1.1%
1.1%
1.2%
2.3%
1.1%
1.1%
1.0%
1.0%
1.1%
1.1%
1.2%
0.0%
0.0%
0.0%
2.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
0.0%
11

12. Treating planned adaptation as an
investment decision
Return on investment via lower O&M,
upgrade and replacement costs
Very sensitive to the discount rate
Shorter upgrade/replacement cycles may be less
costly than initial investment
Flexibility rather than irreversible commitments
However, getting land use right is crucial
Avoid development in flood-affected zones
Provide capacity for future upgrades
12

13. Planned adaptation is justified in some sectors
(Average NPV in $ mln under perfect foresight)
13

14. Planned adaptation - country and discount rate
(NPV for all infrastructure, average over GCMs)
Country
Macedonia
Albania
Kosovo
Serbia
Discount
rate
2%
5%
8%
2%
5%
8%
2%
5%
8%
2%
5%
8%
2016-20
2021-25
2026-30
2031-35
2036-40
2041-45
2046-50
1
-15
-21
-63
-73
-74
10
-1
-6
-38
-95
-115
12
-10
-18
-60
-72
-75
17
3
-4
-13
-84
-110
22
-6
-17
-55
-72
-75
22
4
-3
12
-77
-109
36
-0
-15
-50
-71
-76
28
7
-2
45
-62
-104
46
4
-14
-44
-68
-75
34
10
-1
82
-47
-99
58
9
-12
-36
-63
-71
39
12
0
128
-26
-89
72
17
-6
-27
-57
-67
45
16
3
178
1
-72
14

15. NPV of planned adaptation over GCMs
(Urban assets, $ mln under perfect foresight)
15

16. Robust strategies for adaptation
The optimal strategy depends on the degree
of risk aversion
Risk neutral -> lowest average cost
Extreme risk aversion -> lowest worst outcome
Robust strategies focus on ‘good’ outcomes
For example, in top quartile for most time periods
and/or sectors, plus
No very bad outcomes over all scenarios
Macedonia excl transport – NCAR & IPSL scenarios
16

17. Macedonia payoff matrix – PV of adaption cost
(Lower is better, all infrastructure, $ mln for 2031-35)
Planning scenario
Responsive
BCCR BCM20
CSIRO MK30
MIROC 32
NCAR CCSM30
UKMO HADCM3
Outcome scenario
BCCR
CSIRO
29
10
34
33
39
34
39
35
37
34
55
54
MIROC
59
46
78
35
37
54
NCAR
42
41
56
35
34
54
UKMO
52
55
75
45
47
59
Lowest cost of adaptation
Comparison under perfect foresight
Responsive
29
10
Planned
34
34
NPV of investment
-6
-24
Equal probabilities
Mean
Worst
38
59
42
55
56
78
38
45
38
47
55
59
38
59
35
24
42
34
8
52
59
-7
SD
19
9
20
4
5
2
45
38
39
-1
17

18. Identifying a robust strategy for non-transport
infrastructure
18

19. Analysis of extreme events: how much
protection?
Forget climate change for a while
Do we understand the distribution of extreme events today?
If not, what information do we need to examine this?
Will economic development increase or reduce vulnerability?
What is an efficient level of protection against extreme
events today or in future
Planning for managing extreme events
For Brazil: allowing for the role of El Niño
Investment in infrastructure vs institutional responses
Changes in the trade-offs between costs and risks
19

20. Extreme events and climate change
The effects of climate change: intensity & frequency
Shifting the distributions of extreme events
Tropical cyclones: sea surface temperatures, other factors
Flooding: cumulative vs transitional (run-off)
Droughts: period without rain or probability that rain <
evapotranspiration + run-off over extended period
Example: Flooding in China
Seasonal flooding in Yangtze Basin: driver is variability in monthly
(or even longer) precipitation in upper & middle basin
Storm-related floods caused by cyclones or similar events
Changes in water management and urbanization which may
alter/accelerate run-off: hydro-power vs flood management
20

21. Analysis of extreme events: forms of
adaptation
Increasing resilience and/or reducing vulnerability
Land use and urban planning: don’t put assets in harm’s way
But, attractions of flood plains and coastal zones
Building codes, storm water drainage systems, etc
Civil defense, evacuation plans, shelters, effective governance
Investment in infrastructure
Coastal and river flood defenses: always at risk unless they are
built to very high standards (e.g. Netherlands)
Diversion of flood waters: analogy to interruptible contracts for
power, but what happens when the event occurs?
How far ahead should we look and what levels of protection should
be adopted?
21