The selection of methods for projecting future impacts of climate change starts with a determination of whether causal relationships between variables internal to the study unit and the external drivers of change can be formally represented as a computational model. In adaptation situations where models are not available,
vulnerability indication approaches can be used to say something about possible future impacts based on data collected on the current state of the study unit. Alternatively, knowledge elicitation provides a means of surveying and classifying expert and lay opinions about climate change and its potential impacts.
Modelling future impacts involves the deployment of methods and tools drawn from a
formidable and ever-expanding range of options.
br>
Table
3-6 is a matrix of impact studies, divided by sector of analysis and
geographical location. Symbols after each study indicate the
methods employed by the study: various types of modelling,
integrated assessment, participatory scenario development, expert
judgment and indicators. Some of the
studies—particularly those with a global focus—use
historical data as analogues, or base their methods around
existing literature reviews. On the whole, studies presented
in this table are impact assessments looking to the future that use
climate projections and provide analysis on how those
projections will impact on the various sectors in the various
locations.
Table 3-6: Selection of
impact studies, divided by sector and geographical focus, and
highlighting methods
employed. Symbols are explained at the foot of the Table.
Location | Europe |
North
America | South
America | Africa
and
Middle
East | Asia |
Australasia | Global |
Sector | |
| | |
| | |
Agriculture |
Abildtrup
et al,
2006 * ^
Falloon
and
Betts,
2010 ! |
Zhang
et
al, 2011b ! |
Jones
and
Thornton,
2003 %
Meza et al,
2008 % @
Ruane et al,
forthcoming % |
Abraha
and
Savage,
2006 %
Al Bakri
et al,
2011 %
Jones and
Thornton,
2003 %
Roudier
et al,
2011 !
Thornton
et al,
2010 % |
Chavas
et al,
2009 %
Lioubimtseva
and Henebry,
2009 @
Masutomi et
al, 2009 %
Srivastava et
al, 2010 %
Xiong et al,
2008 %
Wei et al,
2009 % &
Thomson et
al, 2006 %
Simelton et
al, 2009 + @ |
Luo et al,
2003 %
Pearson et
al, 2011 ! ~ |
Berg et al,
2012 “
(tropics)
Fraser, 2006 $
(famines)
Jacxsens et al,
2010 (food
safety supply
chain) !
Kang et al,
2009 % &
Mera et al,
2006 %
(soybean and
maize)
Nardone et al,
2010 @
(livestock)
Ramirez-
Vallegas et al,
forthcoming % ~
(sorghum)
Sutherst et al,
2000 !
(pests)
Thornton et
al, 2009 @
(livestock
developing
countries) |
Pollution |
Alcamo
et al,
2002 ^ |
McDonald
et al, 2005 @ |
| | | | |
Coasts and Fisheries (marine) | Philippart
et al,
2011 @ |
| | | | | Badjeck et
al,
2010 £
Brander,
2010 ! |
Ecosystems and/or biodiversity |
De
Chazal et
al, 2008 ! *
Lindner
et al,
2010 ! ^
Van
Minnen
et al,
2002 ! +
Schröter
et al,
2005 !
Metzger
et al,
2008 ! + |
Andalo et
al, 2005 !
Coops and
Waring,
2011 !
Coops et
al, 2012 !
Dale et al,
2010 ?
Dalla
Valle et
al, 2007 !
Ehman et
al, 2002 ?
Ivits et al,
2012 !
MacRae
et al, 2008 ? !
Nitschke
and Innes,
2008 ?
Taner et
al, 2011 ? |
| Pettorrelli
et al,
2012 “ |
Tanaka et
al,
2012 ! |
| Chakraborty
et al, 2000
(plant
diseases) !
Sekercioglu
et al, 2012 ! @
(birds)
Sietz et al,
2011 ^ (drylands)
Stock et al,
2011 !
(living
marine
resources) |
Urban |
Bonazza
et al,
2009 ! |
Hayhoe et
al, 2010 ^
Wuebbles
et al, 2010
^ | Romero
Lankao et
al, 2012 ^
@ (more
adaptation,
less quant) | |
| | Gasper et
al,
2011 @
Li et al, 2012
! (energy use
in buildings)
Romero
Lankao and
Qin, 2011 @
Willems et al,
2012 !
(urban
drainage) |
Water |
Eckhardt
and
Ulbrich,
2003 &
Falloon
and
Betts,
2010 ! |
Boyer
et
al, 2010 &
Chang
and Jung
2010 &
Kienzle et
al, 2012 &
Zhang et
al, 2011a & |
| | De
Silva et
al, 2007 &
Kelkar et al
2008 & #
Lioubimtseva
and Henebry,
2009 @
Park et al,
2010 @
Park et al,
2011 @
Varis et al,
2012 ! + |
| Green
et al,
2011 @
(groundwater) |
Transport |
| | | | | | Koetse
and
Rietveld,
2009 @ |
Health | | Patz
et al,
2008 ! |
Romero
Lankao et
al, 2012 ^ @ (more
adaptation,
less quant) | | Lioubimtseva
and Henebry,
2009 @
Nelson, 2003
@
Vineis et al
2011 @ |
| |
Energy | | Burkett,
2011! @ |
| | | | Mideksa
and
Kallbekken,
2010 @ |
Coasts | | | | | | | Nicholls,
2002 ! (sea
level
flooding) |
Key for methods:
* =
participatory scenario development
~ = expert
judgment
^ =
integrated model/integrated assessment
% = crop
simulation model
£
= livelihoods framework
“
= vegetation models
? = forest
ecosystem models
! = modelling
& =
water models
$ =
landscape ecology
@ =
literature review / analysis / historical data
# =
participatory knowledge elicitation
+ =
indicators
A large proportion of climate change impact assessments
make use of predictive models that describe the causal relationships
between climate and a study unit. However, modelling tools tend to be
available only for certain sectors such as agriculture, water
resources, coastal zones, and terrestrial ecosystems. Technical
requirements for projecting climate change impacts are generally high
and often difficult to meet, so in many cases it will be preferable to
adopt an existing model and tailor it for the adaptation context or to
meet specific assessment needs. Models vary enormously in their
complexity, in the spatial and temporal scale of their application, and
in their assumptions about adaptation, but the process of impact
projection (Box 3-5) is generally the same: select climate and
socio-economic scenarios, select adaptation options and strategies,
then compute impacts. Each of these steps is described in detail in the
following sub-sections.
Box 3 5: Overview of Impact
Projection
Theoretical assumptions
- Interaction
between the study unit and drivers of change can be
formally
represented as a computational model - Adaptation can
be formally represented as a computational model
Question addressed
- What
are the impacts of climate change?
Data requirements
- Climate
and socio-economic scenarios
- Information about
adaptation options
Typical result A
list of propositions that map each scenario and strategy for adaptation
to an impact.
Generic steps 1.
Select climate and socio-economic scenarios 2. Select
adaptation strategies 3. Compute the impacts of the
scenarios and adaptations |
Representing
adaptationProjecting
impacts of climate change depends not only on the climate and
socio-economic scenarios that are selected, but also on the assumptions
that are made about adaptation. It is therefore important to carefully
consider whether to choose models that project
potential impacts, which are
those that “may occur without considering
adaptation” (Parry et al. 2007: 876), in contrast to tools
that project
residual
impacts, which include adaptation.
Most
natural and human systems will undergo some form of autonomous
adjustment in response to either gradual changes in climate or sudden
shocks, so it is generally understood that potential impacts will
almost certainly not occur. However, it is important to note that the
purpose of representing adaptation in impact projection is not to
compute an optimal adaptation policy, but to model how different
assumptions about the kinds of adjustments that are possible translate
into differences in impacts. In other words, the selection of
adaptation strategies to represent in impact projection serves the same
purpose as the selection of climate and socio-economic scenarios, i.e.
to explore a range of possible futures.