Assessment of climate change over the Eastern Mediterranean and Middle East (EMME) region Dr. Christos Giannakopoulos and Dr. M. Petrakis National Observatory

Assessment of climate change over the Eastern Mediterranean and Middle East (EMME) region

Dr. Christos Giannakopoulos and Dr. M. Petrakis

National Observatory of Athens, Athens, Greece

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Global and Regional Climate Models

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Regional Climate Models

• Regional climate models add further detail to global climate analyses or simulations and study climate processes in more detail than global models allow.

•They are the best available tools so far to study regional or local climate change, as is the case of the island of Cyprus.

•Their typical horizontal resolution is 25kmx25km

25 km

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The main model used in our

climate projections is the

PRECIS regional climate

model;, the domain of the

PRECIS runs covers the East

Mediterranean and Middle

East (EMME) : 22o to 46oN &

10o to 62oE. Cyprus lies in the

centre of this domain.

Regional Models used (2)

EMME region

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Additionally six RCMs of the

EU funded ENSEMBLES

project which cover the

European domain with

Cyprus in their borders, have

also been used namely:

KNMI, METNO, CNRM, METO,

C4I and MPI. The results of

six models were used as an

ensemble mean for testing

and comparing with the

respective results of the

PRECIS RCM.

Regional Models used (3)

• The daily projections used in the present study, are derived from the PRECIS regional climate model (RCM).

• Region of interest is the East Mediterranean and Middle East (EMME) : 22o to 46oN & 10o to 62oE.

• Horizontal resolution of 25km (horizontal resolution of 0.22° latitude and longitude and 19 vertical levels), employing the IPCC SRES A1B emissions scenario.

• The control run represents the base period 1961-1990 and is used as reference for comparison with future projections of 2070-2099.

EMME region

Regional climate model data

Extreme Climate Events - IndicesExtreme Climate Events - Indices

Index Definitionwarm days daily maximum temperature is over

25o C

hot days daily maximum temperature is over 35o C

frost nights daily minimum temperature is below 0o C

tropical nights daily minimum temperature is over 20o C

wet days daily rainfall rate exceeds 1.0 mm

heavy precip. days daily rainfall rate exceeds 10.0 mm

Climate Indices 1961-1990 Differences in climate indices: future - control

Annual number of days with TX>25oC ranges from 1 month (in elevated areas) to 3 months in the N-EMME, while in the S-EMME 2/3 of the year can be considered as warm days.

Hot days at a maximum 30-50 days/year in low elevation areas of the N-EMME and less than a month in areas of higher altitudes. In the S-EMME, such days are common occurring up to 5 months/year (Gulf region).

The number of warm days is found to increase in particular in N-EMME by 50-60 additional days/year by the end of the 21st century.

Low-elevation and coastal regions in Ν-ΕΜΜΕ are estimated to experience about 1-2 extra months with TX>35oC, while S-ΕΜΜΕ are expected to face severe warm conditions with 2 additional months of hot days/year.

Climate Indices 1961-1990 Differences in climate indices: future (2021-2050) - control

In Cyprus the continental lowlands have close to two months temperatures above 35C. This decreases gradually as we approach the coastline

Low-elevation continental regions in Cyprus are estimated to experience about 1 extra months with TX>35oC, while coastal regions will see much smaller changes in the near future.


Continental (above 36οN) and high-altitude areas experience up to 150 frost days/year, while in the south the annual number of frost days does not exceed 20 days/year.

The number of frost days is found to decline within a range of 1-2 months of fewer frost days/year (in high-latitude continental and high-altitude locations).

Tropical nights (TN>20oC) are rare (up to 1 month/year) in the northern EMME, whereas in the south occur typically 1-2 months and more than 3 months/year around the Persian Gulf.

The change in the number of tropical nights translates to 1-2 additional months of tropical nights/year in the north and to 3 additional months in the southern EMME by the end of the 21st century.


More ha

Coastal regions have more. than two months with Tmin>20C but the higher elevation areas have less than 1 month.

In the near future, the western part and the higher elevation areas will see increases of 1 month while smaller increases will be evident in the rest of the island.


The number of wet days ranges from 200 days/year in high altitudes and approximately 100 days/year in N-EMME to less than 40 days/year in S-EMME.

In the N-EMME the number of wet days may decrease by 10-30 days/year.

In the W-Balkan Peninsula and other high-elevation areas heavy precipitation occurs maximum 40-50 days/year. Heavy precipitation days are unusual in the S-EMME region.

Ιn N-EMME the number of days with heavy precipitation is likely to decrease in the high-elevation areas by 15 days/year by the end of the 21st century.


More than 5 months of wet days in the western part and higher elevation areas but less than 3 in the eastern part.

Greater decreases in the eastern part of the island where we already have drier conditions.

Cooling energy requirements

•We use the concept of degree-days, defined as the difference (in oC) of the diurnal mean temperature compared to a base temperature

•Here, we use 25oC for CDDs of particular interest for this region

•An illustrative view of the increasing cooling demands in the region is provided by the mean number of days/year during which cooling will need to exceed 5oC (CDD>5oC), comparing the control and mid-century periods. It indicates the additional strong cooling needed to provide comfortable living conditions and cope with heat waves.

Cooling energy requirements

•Left Figure shows that during the control period the no of days with CDD>5oC in the northern and coastal parts is typically less than a few weeks to one month, while this is 2-3 months in the southern desert areas and up to 5 months around the Gulf.

•The projected change in the 2040-2069 period appears to be quite drastic, with 3-6 weeks in the northern and coastal areas, one month around the Gulf, up to 2 months in parts of Syria, southern Israel, Jordan, parts of Saudi Arabia, Egypt and Libya.


More than one month of heavy cooling is required for continental lowlands.

An additional month of heavy cooling for continental lowlands.

Population Discomfort

•Heat effects on human comfort (or discomfort) is assessed by computing the humidex, an index employed to express the temperature perceived by people.

•Humidex is applied in summer and generally warm periods and describes the temperature felt by an individual exposed to heat and humidity.

•Six humidex categories have been established, to inform the general public for discomfort conditions:< 29oC: no discomfort 30-34oC: some discomfort 35-39oC: discomfort; avoid intense exertion 40-45oC: great discomfort; avoid exertion 46-53oC: significant danger; avoid any activity > 54oC: imminent danger, heatstroke

•Humidex of 38oC has been chosen as threshold in this study.

Population Discomfort

•In the control period, most parts of Greece and Western Turkey have around a month of thermal discomfort days for the population. This value reaches 3 or more months for North Africa and south parts of the Arabian peninsula. Interestingly, coastal and island regions are equally vulnerable.

•For coastal regions in the Eastern parts of Greece, Crete, western/central Turkey and Cyprus, the duration of the period with humidex>38oC is projected to increase by as many as 50 days in 2040-2069.Even larger increases of 70 days are projected for the Arabian peninsula. Smaller changes are evident in mountainous areas (eg. Balkans, Anatolia) i.e. their cool summer climate should be maintained.


The continental interior has currently the highest number of discomfort days – around 80

Greater increases (more than 1 month) along the south coast and inerior

Trend analysis of long-term temperature time series at 18 cities in the study area over the period 1901-2100.

Future Climate–Trends T

Trends: large positive trends approaching 0.40oC per decade are found for Doha and Nicosia. For minimum temperatures, the trends are higher. These trends indicate that the region warms much more strongly than the global mean of 2.8°C until the end of the century – estimated relative to pre-industrial conditions –for the A1B scenario.

The anticipated rapid warming in the EMME in the 21st century, combined with a general drying tendency, and the greater frequency of extreme climate events can have adverse impacts.

The region’s economy is especially vulnerable because of the range of potential impacts1. Direct economic impacts (agriculture, tourism and energy systems)2. Social impacts (deteriorating air quality, human health, spreading of vector borne diseases)3. Indirect impacts (availability of fresh water, biodiversity loss - terrestrial and marine ecosystems)

Documents

Assessment of climate change over the Eastern Mediterranean and Middle East (EMME) region Dr. Christos Giannakopoulos and Dr. M. Petrakis National Observatory