Climate Change Scenarios for Tourist Destinations in St Lucia: Pigeon Causeway to Rodney Bay and Soufriere

1. Climate ChangeClimate ChangeClimate ChangeClimate Change
Scenarios for TouristScenarios for Tourist
Destinations in St Lucia:Destinations in St Lucia:
Pigeon Causeway toPigeon Causeway toPigeon Causeway toPigeon Causeway to
Rodney Bay andRodney Bay and
S f ièS f ièSoufrièreSoufrièrewww.cep.unep.org
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Carolina Cavazos-Guerra, Oxford University

2. Climate Change Scenarios forClimate Change Scenarios for
D ti ti t S i t L iD ti ti t S i t L iDestinations at Saint LuciaDestinations at Saint Lucia
Gathering and
analysing climate
i) Observed Climate
ii) Modelled Climate
a) Regional Scale
b) National Scale
change data
ii) Modelled Climate
c) Destinational Scale
Use data to identify potential impacts
and vulnerabilities on Pigeon
Human health
Agriculture and fisheries
Run-off and soil erosion
Causeway to Rodney Bay and Soufrière Biodiversity and habitat loss
Affectation to Tourism Sector
Making a climate change data bank available
for further impacts studies
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o u t e pacts stud es

3. Climate Change Data StudiesClimate Change Data Studies
Is there evidence of long-
term trends in the climate
What are the
characteristics of
What year to year
variations are seen in
‘normal’ or current
••Observed DataObserved Data
in past decades?current climate?
normal or current
climate?
• Past and Present climate 1960-2009
◦National scale: Gridded data sets from different sources
◦Local scale:Records from Weather stations, but also satellite data...
Is there evidence of long-
term trends in the climate
What will the
characteristics of
What variations will be
seen in ‘normal’ for the
••Modeled DataModeled Data
in future decades?future climate? future climate?
◦Projections for the future from Global Climate Models (GCMs)
◦Projections from Regional Climate Models (RCMs)
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4. Future Climate ScenariosFuture Climate Scenarios
What changes are expected in the future??
What is the magnitude of this changes?What is the magnitude of this changes?
Is it possible to identify these changesIs it possible to identify these changes NOWNOW??Is it possible to identify these changesIs it possible to identify these changes NOWNOW??
1.
Emissions
Scenarios
2. GCM Simulated
Climate response
3. Downscaling
Local Climate
response
4. Impacts
Scenarios
p
response
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5. 1. Emissions Scenarios1. Emissions Scenarios
‘What will happen to the climate if....’
Estimate carbon emissions based on different scenarios of societal change
e g attitudes population technological developmentse.g. attitudes, population, technological developments
Current
A1B
medium emissions
(rapid economic growth
B1
low emissions
(a more environmentally
A2
high emissions
(high population growth(rapid economic growth
but with decreasing
reliance on fossil fuels)
( y
sustainable approach, lower
consumption and lower
population growth.)
(high population growth,
strong emphasis on
economic development)
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They are neither predictions nor forecasts.

6. Future Climate ScenariosFuture Climate Scenarios
What changes are expected in the future??
What is the magnitude of this changes?What is the magnitude of this changes?
Is it possible to identify these changesIs it possible to identify these changes NOWNOW??Is it possible to identify these changesIs it possible to identify these changes NOWNOW??
1.
Emissions
Scenarios
2. GCM Simulated
Climate response
3. Downscaling
Local Climate
response
4. Impacts
Scenarios
p
response
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7. Atmosphere
Horizontal exchange
between columns of
momentum, heat and
moistureAtmosphere
Vertical exchange
Run-off
Biosphere
g
between layers of
momentum, heat and
moisture
Land surface
E.g. Topography,
Hydrology, Ice
Sheets, Vegetation
cover
2 How does2 How does Ocean Layers
Vertical exchange
of water, heat, salt,
nutrients... Ocean layers
Horizontal exchange of
t h t lt
2. How does2. How does
a GCM worka GCM work
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water, heat, salt,
nutrients etc

8. Atmosphere
Horizontal exchange
between columns of
momentum, heat and
moistureAtmosphere
Vertical exchange
Run-off
Biosphere
g
between layers of
momentum, heat and
moisture
Land surface
E.g. Topography,
Hydrology, Ice
Sheets, Vegetation
cover
2 How does2 How does Ocean Layers
Vertical exchange
of water, heat, salt,
nutrients... Ocean layers
Horizontal exchange of
t h t lt
2. How does2. How does
a GCM worka GCM work
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water, heat, salt,
nutrients etc

9. How GCMHow GCMHow GCMHow GCM
models havemodels have
evolved throughevolved through
ti ?ti ?time?time?
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10. The Caribbean in GCM BoxesThe Caribbean in GCM Boxes
Simulate large scale global circulation
The Caribbean in GCM BoxesThe Caribbean in GCM Boxes
Simulate large scale global circulation
patters that determine climate
2.5˚ lat/lon resolution
BUT:
Cannot resolve many importantCannot resolve many important
processes at this coarse resolution e.g.
Storms/hurricanes.
Cannot simulate land-sea interactions
Cannot represent fully the topography
i l k– mountains, lakes etc
Doesn’t give ‘local’ enough projections
for small scale climate impact assessment
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for small scale climate impact assessment

11. Future Climate ScenariosFuture Climate Scenarios
What changes are expected in the future??
What is the magnitude of this changes?What is the magnitude of this changes?
Is it possible to identify these changesIs it possible to identify these changes NOWNOW??Is it possible to identify these changesIs it possible to identify these changes NOWNOW??
1.
Emissions
Scenarios
2. GCM Simulated
Climate response
3. Downscaling
Local Climate
response
4. Impacts
Scenarios
p
response
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12. 3. Downscalings with Regional3. Downscalings with Regional3. Downscalings with Regional3. Downscalings with Regional
Climate Models (RCMs)Climate Models (RCMs)
Do nscale to higher spatial resol tion
50 km
Downscale to higher spatial resolution
Model smaller regions with boundaryModel smaller regions with boundary
conditions from a GCM
Higher resolution allows more realistic
representation of physical processes
PRECIS- Driven by 2 different GCMs
(ECHAM-4 and HadCM3)
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( C a d adC 3)

13. Regional Scale Country Scale Destinational ScaleRegional Scale
(Caribbean)
Country Scale
(Saint Lucia) (Pigeon Causeway to Rodney
Bay and Soufrière)
www.gettyimages.com/detail/10155933/Riser
www.maps.com/map.aspx?pid=16526
Gridded observational datasets
Local Observation
Stations (if available)
Ensemble of 15 IPCC
One Regional Model (2 driving GCMS)
Stations (if available)
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Global Models
One Regional Model (2 driving GCMS)

14. Climate VariablesClimate Variables
Directly projected from climate models
Temperature (minimum, mean, maximum)
Rainfall (total, intensity, number of rainy days, timing of seasonal rainfall,
length of dry spells)length of dry spells)
Relative Humidity
Sea-surface temperatures
Wind speedWind speed
Cloud cover (sunshine hours)
Calculated from these variables
Indices of extreme daily temperature:d ces o e t e e da y te pe atu e
◦ Frecuency of Hot and Cold days
◦ Frecuency of Hot and Cold nights
Indices of extreme daily precipitation:
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y
◦ Maximum 1-day rainfall
◦ Maximum 5-day rainfall

15. Saint Lucia: Temperature ChangesSaint Lucia: Temperature Changes
Observed increase 0.16˚
per decade (1961 2000)per decade (1961-2000)
2050s
(+0.9) +1.4˚(+1.7)
(+1.0) +1.4˚(+1.8)
2080s
(+1.8) +2.3(+3.1)
(+1.2) +2.1˚(+3.2)
2020s
(+0.3) +0.7˚(+0.8)
(+0.3) +0.7˚(+1)
Under the A2 Scenario...
(+0.6) +1.1˚(+1.2) (+0.9) +1.4˚(+2.0(+0.3) +0.7˚(+0.8)
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16. Saint Lucia: Temperature ChangesSaint Lucia: Temperature Changes
20802080s
PRECIS Echam4
Under the A2 Scenario...
PRECIS Echam4
+3.3˚C
PRECIS HadCM3
2 4˚C
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+2.4˚C

17. Saint Lucia: Rainfall ChangesSaint Lucia: Rainfall Changes
Trends indicate slight reduction in rainfall
2050s
(-35) -9% (+7)
(-33) -10% (+6)
2080s
(-66) -23% (+12)
(-52) -15% (+10)
2020s
(-28) -5% (+8)
(-19) -4% (+10)
(-34) -5% (+3) (-38) -9% (+14)(-20) -5% (+14)
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18. Saint Lucia: Rainfall ChangesSaint Lucia: Rainfall Changes
PRECIS Echam4
Under the A2 Scenario...
2080s
PRECIS Echam4
-11%
PRECIS HadCM3
32%
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-32%

19. ExtremesExtremes
Frequency of ‘Hot days’ ‘Cold days’ ‘Hot nights’ andFrequency of Hot days , Cold days , Hot nights and
‘Cold nights’
◦ Using daily maximum and minimum temperature records,
T t d d i t li t 1 i 10 dTemperature exceeded in current climate every 1 in 10 days...
◦ Different value for every region and season
◦ How often will this temperature be exceeded in the future? (i.e.
Might the temperature that we currently consider to be relatively
‘hot’ or ‘cold’ in current climate become more normal in future?
Maximum 1-day and 5-day total rainfallsy y
Proportion of rainfall that occurs in ‘Heavy’ events
Number of consecutive dry-days
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20. Saint Lucia: Hot DaysSaint Lucia: Hot Days
2050s
(38) 54% (64)
(39) 59% (64)
(30) 43% (49)
2080s
(55) 83% (97)
(45) 77% (88)
(35) 48% (68)
Under the A2 Scenario...
( ) ( ) ( ) ( )
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21. Saint Lucia: Cold DaysSaint Lucia: Cold Days
Practically no cold days for all scenarios
Under the A2 Scenario...
2050s
(0) 0% (0)
(0) 0% (0)
(0) 0% (1)
2080s
(0) 0% (0)
(0) 0% (0)
(0) 0% (0)( ) ( ) ( ) ( )
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22. Saint Lucia: Heavy RainfallSaint Lucia: Heavy Rainfall
2050s
(-19) -1 (2)
(-17) -1 (4)
(-20) 0 (3)
2090s
(-25) -3 (2)
(-26) -3 (1)
(-21) -1 (7)
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23. How these results are interpretedHow these results are interpreted
Physical Impacts
Projected from climate models
Physical Impacts
• Water quality and availability
• Ocean acidity
• Flooding – from coasts or
heavy rainfall
Indirect
Temperature Rainfall
Humidity
Sea-surface temperatures
heavy rainfall
• Coastal erosion
• Run-off and Soil Erosion
Wind speed
Cloud cover (sunshine hours)
Extremes
Additional info required
Agriculture
Water
Climate
E i
Transport
Sea-level rise
Storm surge incidence
Sustainable
Caribbean
Tourism
DestinationsNatural
Health
InfrastructureEconomic
Development
g
Storms and Hurricanes:
Frequency, intensity, paths
Direct
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Resources
Energy
Waste
Management
Security

24. Sea Level RiseSea Level Rise
Picture to be inserted hereWhat we knowPicture to be inserted here
R h t f 2007
What we know
about future SLR:
The oceans can be
expected to ‘expand’ with
Rahmstorf, 2007
55-125 cm
IPCC 2007
increasing temperature at a
reasonably predictable rate
What we aren’t sureIPCC, 2007
18-59 cm
What we aren t sure
about future SLR:
How quickly will the
Antarctic and Greenland
Ice-sheets will melt?
We must consider a
wide range of possiblewide range of possible
SLR increases
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25. Tropical CyclonesTropical Cyclones
What we know about TCs and
Climate Change
What we aren’t sure about
TCs and Climate Change
1)The intensity of North Atlantic TCs
has increased since 1970...
• ... long-term climate change signal
or inter-decadal variability?
2) TC intensity is strongly correlated
with SST, and SSTs are rising...
• ... but how might the frequency of TCs
change (formation is dependent on a
number of conditions e.g. Wind shear)??
3) TC intensity is likely to increase as
SSTs increase. i.e. peak wind speed
(+3-20%) rainfall intensity (+10-35%)
g )
(+3-20%), rainfall intensity (+10-35%).
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26. Summary 1Summary 1
Estimate future changes in primary climateEstimate future changes in primary climate
variables using a combination of observed data
and global and regional model scenariosand global and regional model scenarios
Combination of GCM’s and RCM’s data allows us
to maximise the data available to usto maximise the data available to us
◦ Regional models maximise the spatial detail and realism
in the modelsin the models
◦ Global model projections allow us to compare multiple
models to give an uncertainty range
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27. Summary 2Summary 2
o Projections of temperature indicate:
GCM’s Increases in temperature of around 0 6-1 7˚ by 2050sGCM s Increases in temperature of around 0.6 1.7 by 2050s
and 1.2 to 3.1° by 2080s
RCM’s The PRECIS HadCM3 indicate 3.3° the PRECIS
Echam4 indicates an increase of 2 4° by 2080’sEcham4 indicates an increase of 2.4° by 2080 s.
o Projections of rainfall indicate:j
GCM’s All projections indicate critical decrease in rainfall: range
from -35% to +7% in annual rainfall by 2050s, and -66% to +14%
by 2080sby 2080s
RCM’s The PRECIS HadCM3 indicate -32%, the PRECIS
Echam4 indicates a reduction of -11%
o We may see an accelerated response in climate extremes
compared with the mean
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p

28. Constraints, recommendations andConstraints, recommendations and
Future DirectionsFuture DirectionsFuture DirectionsFuture Directions
Observed climate data not always available (sparse in the Caribbean).
which restricts the deductions we can make regarding the changes
that have already occurred.
Climate models have demonstrable skill in reproducing the large-
scale characteristics of the global climate dynamics, there remain
substantial deficiencies
i) Limitations resolution imposed by available computing power
ii) Deficiencies in scientific understanding of some processes
iii) limited spatial resolution restricts the representation of many of theiii) limited spatial resolution restricts the representation of many of the
smaller Caribbean Islands even for RCM)
F h i f i b d l i h l l l l i hFurther information about model uncertainty at the local level might
be drawn if additional regional model simulations based on a range
of differing GCMs and RCMs were generated for the Caribbean region
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in the future.

29. c cavazos@ucl ac uk
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c.cavazos@ucl.ac.uk