This document discusses gathering and analyzing climate change data at regional, national, and destination scales. It describes observing historical climate data from weather stations and satellites, and projecting future climate using global and regional climate models under different emissions scenarios. The models simulate changes in temperature, precipitation, hurricanes, sea level rise and other climate variables. The results can identify potential climate impacts and vulnerabilities to inform further studies.

4. Gathering and analysing climate
change data
1 ) Observed climate1.) Observed climate
2.) Modelled climate
At (a) Regional (b) National and (c)At (a) Regional (b) National and (c)
Destinational scale
Use data to identify potentialUse data to identify potential
impacts and vulnerabilities on
Eleuthera
Making a climate change data
bank available for further
impacts studiesimpacts studies

5. Is there evidence
of long-term
trends in the
What are the
characteristics
of current
What year-to-year or
decade-to-decade
variations are seen in
climate in recent
decades?
of current
climate?
‘normal’ or current
climate? E.g. El Nino....
◦ Observations 1900-2009...
◦ Mainly records from weather◦ Mainly records from weather
stations, but also Satellite data in
recent years...y

6. • Projections of the future from Global or
Regional climate modelsRegional climate models
1.
Emissions
2. GCM
Simulated
Climate
3.
Downscaling
Local Climate
4.
Impacts
Scenarios
Climate
Response
Local Climate
response
Impacts

7. Hypothetical, but plausible, scenarios of global socio-economic
h ‘Wh t ill h t th li t if ’change. ‘What will happen to the climate if...’
Estimate carbon emissions based on different scenarios of societal
change e.g. attitudes, population, technological developments
A2A1B
d
B1A2
high emissions
(high population growth,
strong emphasis on
economic development)
medium emissions
(rapid economic
growth but with
decreasing reliance on
fossil fuels)
low emissions
(a more environmentally
sustainable approach, lower
consumption and lower
population growth.)) population growth.)

8. Atmosphere
Cloud
Types
Radiatively
Active
gases and
Horizontal exchange
between columns of
momentum, heat and
moistureAtmosphere
Vertical exchange
Run-off
L d h Di l d
Ice
g
aerosols
↓ Precipitation
Sea
Momentum,
latent and
sensible heat
fluxes
Biosphere
g
between layers of
momentum, heat and
moisture
Land heat
and
moisture
storage
Diurnal and
seasonal
penetration
Sea
Ice
Surface Ocean Layers
2 How2 How Land surface
E.g. Topography,
Hydrology, Ice
Sheets,
Vegetation cover
2. How2. How
does adoes a
GCMGCM
g
O L
GCMGCM
work?work? Ocean Layers
Vertical exchange
of water, heat,
salt, nutrients... Ocean layers
Horizontal exchange
of water heat salt
work?work?
of water, heat, salt,
nutrients etc

9. • Simulate the large scaleg
global circulation
patterns that determine
climate
• Cannot represent fully
the topography –
mountains, lakes etc
• cannot simulate
land-sea
interactions, sea
breezebreeze
• Cannot resolve many
important physical
processes at this coarse
resolution e.g.
Storms/hurricanesStorms/hurricanes.

10. PRECIS - driven by 2 different
GCMS (ECHAM-4 and HadCM3)
INSMET, CCCCC and UWI.
‘Downscale’ to 50km and 25km
spatial resolutions
Model a smaller regions, given
‘boundary conditions’ from a GCM
h l llHigher resolution allows more
realistic representation of physical
processes

11. Ensemble of
Regional Gridded
15 IPCC
Global
Models
Regional Model
Projections
Regional
Scale
Gridded
observational
datasets
Ensemble of
National
Scale
Gridded
observational
datasets
Ensemble of
15 IPCC
Global
Models
Regional Model
Projections
Models
Destination
Scale
Local
Observation
Stations
Regional Model
Projections
(where available)

12. Observed increase
0.11˚ per decade
2030
2090s
(+2 3) +3 1˚(+3 5)2030s
(+0.6) +0.9˚(+1.2)
(+2.3) +3.1 (+3.5)

13. The Bahamas: ‘Hot’ daysThe Bahamas: ‘Hot’ daysyy
2060s
(26) 40% (47)
2090s
(36) 59% (67)
)

14. No clear trend in recent
observed data
2030s
(-13) -4 % (+10)
2090s
(-30) -7 % (+18)

15. 2090s

16. Primary Climate Variablesy
Temperature, Precipitation, Evaporation ,
Humidity, Wind speed, Sea Surface Temperature, Cloud
cover (sunshine hours)
Hurricane frequency and intensity, Sea-Level riseHurricane frequency and intensity, Sea Level rise
h l dPhysical Impacts and
Vulnerabilities
Human health
Agriculture and fisheries
Linking Variables
Storm Surge
Water quality and availability Agriculture and fisheries
Run-off and soil erosion
Biodiversity and habitat loss
Water quality and availability
Ocean acidity
Flooding – from coasts or heavy
rainfall
Coastal erosionCoastal erosion
Vulnerabilities
in the Tourism
SectorSector

17. IPCC estimate of 0.13-0.56 metres in the
Caribbean by the 2090s relative to 1980-1999...
S l l i Th l E i f O I◦ Sea-level rise = Thermal Expansion of Oceans + Ice
Sheet/Glacier Melt
◦ However: Recent research suggests that ice sheet melt
might accelerate over the coming decades, and not to
continue at the current rate and that IPCC estimates mightcontinue at the current rate, and that IPCC estimates might
underestimate future sea-level rise.
◦ Several independent studies* indicate higher sea-level rise
f 1 5 b h 2090of up to 1.5m by the 2090s.
* e.g. Rahmstorf 2007, Rignot et al, 2008, Rohling et al, 2008g , g , , g ,

18. Climate change and sea-level
irise:
◦ Shift in shore line
◦ Exacerbated coastal erosion
E h d h i h◦ Enhanced storm surge heights
What is the observed rate of
shoreline recession?
◦ Compare current shoreline
position with aerial photography
and satellite archives
What might be the future
position of the shoreline?
◦ Overlay sea-level rise scenarios
onto topography
◦ Identify most vulnerable regions
Ryan Sim, Josh King (Univ. Waterloo)
S R ll (B h D M l )Suzanne Russell (Bahamas Dept. Meteorology)
Carol McSweeney (Univ. Oxford)
With help from Lionel Fernander

19. Storms and HurricanesStorms and Hurricanes
IPCC AR4: ‘Tropical storm and
hurricane frequencies vary considerably
from year to year, but evidence
suggests substantial increases in
intensity and duration since the 1970s.’

20. Estimating future changes in
storm characteristics
IPCC AR4 Summary:
‘a likely increase of peak wind
intensities and notably whereintensities and notably, where
analysed, increased near-storm
precipitation in future tropical
cyclones’
Storms are hurricanes operate on too
small a scale to be resolved by
global or regional climate models
◦ Studies based on high resolution
weather models and statistical
models
Storm surge model
◦ Review literature to make estimates
of changes in intensity, duration,
hurricane season length, and path.
Storm surge model
• Add storm surge to
Digital Elevation
ModelModel

21. Carol.McSweeney@ouce.ox.ac.ukCarol.McSweeney@ouce.ox.ac.uk

22. R lt f b dd d hi h l ti d l dResults from embedded high-resolution models and
global models, ranging in grid spacing from 100 km to 9 km,
project a likely increase of peak wind intensities and notably,
where analysed increased near storm precipitation in futurewhere analysed, increased near-storm precipitation in future
tropical cyclones. Most recent published modelling studies
investigating tropical storm frequency simulate a decrease in
the overall number of storms though there is less confidencethe overall number of storms, though there is less confidence
in these projections and in the projected decrease of relatively
weak storms in most basins, with an increase in the numbers of
the most intense tropical cyclonesthe most intense tropical cyclones.
Tropical storm and hurricane frequencies vary considerably from
year to year, but evidence suggests substantial increases inyea to yea , but e de ce suggests substa t a c eases
intensity and duration since the 1970s.In the extratropics,
variations in tracks and intensity of storms reflect variations in
major features of the atmospheric circulation, such as the Northj p ,
Atlantic Oscillation.

23. Temperature (minimum, mean,
maximum)
Rainfall (total, intensity, number of rainy
days, timing of seasonal rainfall, length Directlyy , g , g
of dry spells)
Humidity
Sea-surface temperatures
projected
from climate
models
Sea surface temperatures
Wind speed
Cloud cover (sunshine hours)
Sea-level rise Water - Quality and availability
Storm surge incidence
Storms and Hurricanes: Frequency,
intensity, paths, and timing
Ocean Acidity
Flooding – Surface and Coastal
Coastal Erosionintensity, paths, and timing Coastal Erosion