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

Climate ChangeClimate ChangeClimate Change Climate Change Scenarios for Tourist Scenarios for Tourist Destinations in St Lucia: Destinations in St Lucia: Pigeon Causeway toPigeon Causeway toPigeon Causeway to Pigeon Causeway to Rodney Bay and Rodney Bay and S f ièS f ièSoufrièreSoufrièrewww.cep.unep.org

1

Carolina Cavazos-Guerra, Oxford University

Climate Change Scenarios for Climate 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 Scaleb) National Scale

change data ii) Modelled Climate c) Destinational Scale

Use data to identify potential impacts and vulnerabilities on Pigeon

Human healthAgriculture and fisheriesRun-off and soil erosion

Causeway to Rodney Bay and Soufrière Biodiversity and habitat lossAffectation to Tourism Sector

Making a climate change data bank available for further impacts studies

2

o u t e pacts stud es

Climate Change Data StudiesClimate Change Data StudiesIs 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)

3

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 changes Is it possible to identify these changes NOWNOW? ?

1. Emissions Scenarios

2. GCM Simulated Climate response

3. DownscalingLocal Climate

response4. Impacts

Scenarios p response

4

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

A1Bmedium emissions

(rapid economic growth

B1low emissions

(a more environmentally

A2high emissions

(high population growth(rapid economic growth but with decreasing

reliance on fossil fuels)

( ysustainable approach, lower

consumption and lower population growth.)

(high population growth, strong emphasis on

economic development)

5

They are neither predictions nor forecasts.








response4. Impacts


6

AtmosphereHorizontal exchange between columns of momentum, heat and moistureAtmosphere

Vertical exchange Run-off

Biosphere

gbetween layers of momentum, heat and moisture

Land surfaceE.g. Topography, Hydrology, Ice Sheets, Vegetation cover

2 How does2 How does Ocean LayersVertical exchange of water, heat, salt, nutrients... Ocean layers

Horizontal exchange of t h t lt

2. How does 2. How does a GCM worka GCM work

7

water, heat, salt, nutrients etc

AtmosphereHorizontal exchange between columns of momentum, heat and moistureAtmosphere

Vertical exchange Run-off

Biosphere

gbetween layers of momentum, heat and moisture

Land surfaceE.g. Topography, Hydrology, Ice Sheets, Vegetation cover

2 How does2 How does Ocean LayersVertical exchange of water, heat, salt, nutrients... Ocean layers

Horizontal exchange of t h t lt

2. How does 2. How does a GCM worka GCM work

8

water, heat, salt, nutrients etc

How GCMHow GCMHow GCM How GCM models have models have evolved through evolved through ti ?ti ?time?time?

9

�The Caribbean in GCM Boxes�The Caribbean in GCM BoxesSimulate large scale global circulation

The Caribbean in GCM BoxesThe Caribbean in GCM BoxesSimulate 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

10

for small scale climate impact assessment








response4. Impacts


11

3. Downscalings with Regional3. Downscalings with Regional3. Downscalings with Regional 3. 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)

12

( C a d adC 3)

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 datasetsLocal Observation

Stations (if available)

Ensemble of 15 IPCC One Regional Model (2 driving GCMS)

Stations (if available)

13

Global Models One Regional Model (2 driving GCMS)

Climate VariablesClimate VariablesDirectly 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 HumiditySea-surface temperaturesWind 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:

14

y◦ Maximum 1-day rainfall◦ Maximum 5-day rainfall

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)

15

Saint Lucia: Temperature ChangesSaint Lucia: Temperature Changes

20802080s

PRECIS Echam4

Under the A2 Scenario...

PRECIS Echam4

+3.3˚C

PRECIS HadCM3

2 4˚C

16

+2.4˚C

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)

17

Saint Lucia: Rainfall ChangesSaint Lucia: Rainfall Changes

PRECIS Echam4

Under the A2 Scenario... 2080s

PRECIS Echam4

-11%

PRECIS HadCM3

32%

18

-32%

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 yProportion of rainfall that occurs in ‘Heavy’ eventsNumber of consecutive dry-days

19

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...( ) ( ) ( ) ( )

20

�Saint Lucia: Cold Days�Saint Lucia: Cold DaysPractically 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)( ) ( ) ( ) ( )

21

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)

22

How these results are interpretedHow these results are interpreted

Physical Impacts

Projected from climate modelsPhysical Impacts• Water quality and availability• Ocean acidity• Flooding – from coasts or heavy rainfall

Indirect

Temperature RainfallHumiditySea-surface temperatures heavy rainfall

• Coastal erosion • Run-off and Soil Erosion

Wind speed Cloud cover (sunshine hours)Extremes

Additional info required

AgricultureWater

Climate

E i

TransportSea-level riseStorm surge incidence

SustainableCaribbean Tourism

DestinationsNatural Health

InfrastructureEconomic Development

gStorms and Hurricanes:

Frequency, intensity, paths

Direct

23

Resources

Energy

Waste Management

Security

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, 200755-125 cm

IPCC 2007

increasing temperature at a reasonably predictable rate

What we aren’t sureIPCC, 200718-59 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

24

Tropical CyclonesTropical CyclonesWhat we know about TCs and

Climate ChangeWhat 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%).

25

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 scenariosCombination 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

26

Summary 2Summary 2o 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 2080sRCM’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:jGCM’s All projections indicate critical decrease in rainfall: range from -35% to +7% in annual rainfall by 2050s, and -66% to +14% by 2080sby 2080sRCM’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

27

p

Constraints, recommendations and Constraints, 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 powerii) Deficiencies in scientific understanding of some processesiii) 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

28

in the future.

c cavazos@ucl ac uk

29

[email protected]

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

Environment

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