This document summarizes Dr. Carol McSweeney's presentation on climate trends and projections for Jamaica. It outlines that observed and model data indicate increases in average temperature, more hot days, and decreases in annual rainfall. Regional climate models provide higher resolution projections of changes in extremes like heavy rainfall. Sea level rise projections range from 0.13-0.56 meters by 2090, and hurricanes may increase in frequency or intensity, though models have coarse resolution. The impacts assessed include effects on health, agriculture, fisheries, biodiversity, flooding and coastal erosion.

1. Dr Carol McSweeney, Oxford University

2. Observed Data
◦ Past and Present climate 1960-2009...
◦ Mainly Records from Weather stations, but also satellite data...
Is there evidence
of long termWhat are the
What year to year
of long-term
trends in the
climate in recent
decades?
What are the
characteristics of
current climate?
y y
variations are seen in
‘normal’ or current
climate? E.g. El Nino....
Model data
◦ Projections of the future from Global or Regional climate
models

3. 1.
Emissions
Scenarios
2. GCM
Simulated
Climate
3.
Downscaling
Local Climate
4.
ImpactsScenarios
Response response
p

4. H th ti l b t l ibl i f l b l i iHypothetical, but plausible, scenarios of global socio-economic
change. ‘What will happen to the climate if...’
Estimate carbon emissions based on different scenarios of societal
h i d l i h l i l d lchange e.g. attitudes, population, technological developments
A1B
d
B1A2medium emissions
(rapid economic
growth but with
decreasing reliance on
fossil fuels)
low emissions
(a more environmentally
sustainable approach, lower
consumption and lower
population growth.)
A2
high emissions
(high population growth,
strong emphasis on
economic development)
) population growth.)

5. 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

6. •Typically 2.5˚
latitude/longitude
resolution
•BUT cannot resolve many
important processes at this
coarse resolution e.g.
St /h iStorms/hurricanes.
•Cannot represent fully the
topography – mountains,
l k tlakes etc
•Doesn’t give ‘local’
enough projections for
ll l li t i tsmall scale climate impact
assessment

7. ‘Downscale’ to typically 50km
or higher spatial resolution
M d l ll iModel a smaller regions,
given ‘boundary conditions’
from a GCM
Higher resolution allows more
realistic representation of
physical processesphysical processes
PRECIS – driven by 2 different
GCMS (ECHAM 4 dGCMS (ECHAM-4 and
HadCM3)

8. Regional scale Country scale
Destinational Scale
Regional scale
(Caribbean)
Country scale
(Jamaica)
(Montego Bay and
Negril
Ensemble of 15
IPCC Global
One Regional
Model
Increasing model resolution
Increasing detail in model
processes and output
Models (2 driving GCMS)

9. Temperature (minimum, mean,
maximum)
Rainfall (total, intensity, number of rainy Directly( , y, y
days, timing of seasonal rainfall, length
of dry spells)
Humidity
Directly
projected
from climate
modelsu d ty
Sea-surface temperatures
Wind speed
Cloud cover (sunshine hours)
models
Cloud cover (sunshine hours)
Sea-level rise Additional
Storm surge
Storms and Hurricanes: Frequency,
intensity, paths, and timing
info
required
y, p , g

10. Observed increase
0.14˚ per decade
2030s
(+0.6) +1.0˚(+1.2)
(+0.5) +1.1˚(+1.3)
(+0 3) +0 8˚(+1 0)
2090s
(+2.5) +3.0˚(+3.5)
(+1.6) +2.6˚(+3.2)
(+1 1) +1 5˚(+2 2)
Under the A2 (high emissions) Scenario...
(+0.3) +0.8 (+1.0) (+1.1) +1.5 (+2.2)

11. No clear trend in recent
observed data
Under the A2 Scenario
2030s
(-35) -3 % (+17)
(-32) -7 % (+9)
(-20) -2 % (+10)
2090s
(-65) -14 % (+3)
(-36) -13 % (+11)
(-30) -2 % (+22)
Under the A2 Scenario... ( 20) 2 % (+10) ( 30) 2 % (+22)

12. Frequency of ‘Hot days’ ‘Cold days’ ‘Hot nights’Frequency of Hot days , Cold days , Hot nights
and ‘Cold nights’
◦ Using daily maximum and minimum temperature records,
Temperature exceeded in current climate every 1 in 10Temperature exceeded in current climate every 1 in 10
days...
◦ Different value for every region and season
H f ill hi b d d i h f ?◦ 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?normal in future?
Maximum 1-day and 5-day total rainfalls
Proportion of rainfall that occurs in ‘Heavy’ eventsProportion of rainfall that occurs in Heavy events
Number of consecutive dry-days

13. Jamaica: ‘Hot’ daysJamaica: ‘Hot’ daysJ yJ y
Under the A2 Scenario...
2060s
(32) 51% (73)
(36) 53% (68)
(27) +42%˚(53)
2090s
(49) 78% (98)
(41) 71% (96)
(30) 52% (66)

14. Jamaica: ‘Cold’ daysJamaica: ‘Cold’ daysJ C yJ C y
Under the A2 Scenario...
2060s
(0) 0% ( 3)
(0) 0% (2)
(0) 1% (3)
2090s
(0) 0% (0)
(0) 0% (1)
(0) 1% (2)

15. Jamaica: Heavy RainfallJamaica: Heavy RainfallJ yJ y
2060s
(-11) 0 6)
(-13) 0 4)
(-14) 0 (6)
2090s
(-19) -1 (7)
(-13) -1 (5)
(-8) -2 (9)
Under the A2 Scenario...

16. 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 I Sh /Gl i◦ Sea-level rise = Thermal Expansion + Ice Sheet/Glacier
Melt
◦ Thermal expansion is relatively easy to predict based on
global temperatures
The response of Ice Sheets and Glaciers is much more◦ The response of Ice Sheets and Glaciers is much more
difficult to predict:
◦ 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 might
underestimate future sea-level rise.

17. Increased frequency?Increased frequency?
Increased intensity?
Increase in Hurricane season length?Increase in Hurricane season length?
Change in path/tracks?
Difficult to determine via modelsDifficult to determine via models
◦ resolution too coarse...
◦ Interactions with ENSO
Combined impacts of changes in
storm/h rricane characteristics and sea le elstorm/hurricane characteristics and sea-level
rise
◦ Changes in Storm Surge Incidence◦ Changes in Storm Surge Incidence

18. Estimate future changes in primary climateEstimate future changes in primary climate
variables using a combination of observed
data and global and regional model scenariosdata and global and regional model scenarios
Combination of global and regional climate
model data allows us to maximise the datamodel data allows us to maximise the data
available to us
◦ Regional models maximise the spatial detail andRegional models maximise the spatial detail and
realism in the models
◦ Global model projections allow us to compare
multiple models to give an uncertainty range

19. Projections from GCMs indicate:Projections from GCMs indicate:
◦ Increases in temperature of around 0.3-1.3˚ by
2030s and 1.2 to 3.5 by 2090s2030s and 1.2 to 3.5 by 2090s
◦ Most models indicate decreases in rainfall –
projections range from -35% to +17% in annual
rainfall by 2030s, and -65% to +22% by 2090s.
◦ We may see an accelerated response in climate
extremes compared with the meanextremes compared with the mean
We still have to analyse the downscaled
regional climate model outputs to look atregional climate model outputs to look at
impacts at destinational scale.

21. Climate Variables
Temperature, Precipitation, Evaporation ,
Humidity, Wind speed, Sea Surface Temperature, Cloud
cover (sunshine hours)
Hurricane frequency and intensity, Sea-Level rise
Physical Impacts andPhysical Impacts and
Vulnerabilities
Human health
Agriculture and fisheries
Linking Variables
Storm Surge
Water quality and availability
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