Investor Presentaiton
More high temperature extremes
FIGURE 3: Percentage of hot days ('heat stress'),
1900-2100
120-
Little change in extreme rainfall
FIGURE 4: Contribution to total annual rainfall from very
wet days ('extreme rainfall' and 'flood risk'), 1900-2100
60-
60
Percentage of hot days (%)
100
60
40
40
20
0
1900
1950
2000
Year
2050
2100
% total annual rainfall from very wet days
10-
40
30-
20-
50
50
1900
1950
2000
Year
2050
2100
The percentage of hot days is projected to
increase substantially from about 10% of all
observed days on average in 1981-2010. Under
a high emissions scenario, about 95% of days
on average are defined as 'hot' by the end-of-
century. If emissions decrease rapidly, about
75% of days on average are 'hot'. Note that the
models overestimate the observed increase
in hot days (about 25% of days on average in
1981-2010 rather than 10%). Similar increases
are seen in hot nightsd (not shown).
FIGURE 5: Standardized Precipitation Index
('drought'), 1900-2100
The Standardized Precipitation Index (SPI) is
a widely used drought index which expresses
rainfall deficits/excesses over timescales ranging
from 1 to 36 months (here 12 months, i.e. SPI12).
It shows how at the same time extremely dry and
extremely wet conditions, relative to the average
local conditions, change in frequency and/or
intensity.
Under a high emissions scenario, SPI12 values
are projected to decrease to about -0.6 on
average by the end of the century (2071-2100),
with a number of models indicating substantially
larger decreases and hence more frequent
and/or intense drought. Year-to-year variability
remains large with wet episodes continuing to
occur into the future.
NOTES
The proportion of total annual rainfall from very
wet days (about 30% for 1981-2010) shows
little change on average by the end-of-century
although the uncertainty range is somewhat
larger (about 10% to almost 50% under a high
emissions scenario). Total annual rainfall is
projected to decrease under a high emissions
scenario (see Figure 2).
I
3.0
1.5-
index 0.0
-1.5
-3.0
1900
1950
2000
Year
2050
2100
very dry
very wet
a Model projections are from CMIP5 for RCP8.5 (high emissions) and RCP2.6 (low emissions). Model anomalies are added to the historical mean and
smoothed.
b Observed historical record of mean temperature and total precipitation is from CRU-TSV3.26. Observed historical records of extremes are from
JRA55 for temperature and from GPCC-FDD for precipitation.
d
Analysis by the Climatic Research Unit, University of East Anglia, 2018.
A 'hot day ('hot night') is a day when maximum (minimum) temperature exceeds the 90th percentile threshold for that time of the year.
The proportion (%) of annual rainfall totals that falls during very wet days, defined as days that are at least as wet as the historically 5% wettest of all days.
f SPI is unitless but can be used to categorize different severities of drought(wet): above +2.0 extremely wet; +2.0 to +1.5 severely wet;
+1.5 to +1.0 moderately wet; +1.0 to +0.5 slightly wet; +0.5 to -0.5 near normal conditions; -0.5 to -1.0 slight drought; -1.0 to -1.5 moderate drought;
-1.5 to -2.0 severe drought; below -2.0 extreme drought.
Dominican Republic
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