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M. A. S. Abdel Monem and I. A. El Ghandour
2.2 At the Regional Level
According to the latest IPCC assessment, the Near East and North Africa (NENA)
region is one of the most vulnerable regions to climatic change. The Region is
predicted to become even hotter and dryer than what it already is. A temperature rising
up to 4 °C is expected by century’s end. Rainfall may decline up to 40% by 2050 (and
up to 60% in a 4 °C scenario), with an increase of severe drought and floods frequency
and intensity. Sea level rise of about 0.1–0.3 m is also expected by the year 2050,
augmenting seawater intrusion to coastal groundwater resources. It is anticipated that
such a climate change scenario would reduce crop yield up to 30%. The livelihoods of
a large segment of the region’s population, particularly those depending on small scale
rainfed agriculture, will be at great risk. The environment will be impacted as well
due to the anticipated increase of desertification, land degradation and biodiversity
losses. Ultimately, people migration will be accelerated.
The demand for a close observation on the impact of climate change on the
Region has materialized through the establishment of the ‘Regional Initiative for
the Assessment of the Impact of Climate Change on Water Resources and SocioEconomic Vulnerability in the Arab Region’ [6].
Within the RICCAR project, future climate change data are generated through
downscaling projections from three global circulation models, EC-EARTH, CNRM
-CM5, and GFDL-ESM, exercised on the region using the regional climate model
RCA4 to provide higher-resolution information (50 km). The two considered climate scenarios are based on selected Representative Concentration Pathways (RCP),
specifically RCP 4.5 (moderate-case scenario) and RCP 8.5 (worst-case scenario).
The projected climatic and hydrological variable considered (max and min temperature, and precipitation, runoff and evapotranspiration) are presented as the change
between the twenty-year periods of 2046–2065 (mid-century) and 2081–2100 (endcentury) with reference to the baseline period of 1986–2005. Here we highlight some
relevant findings for temperature, precipitation and evapotranspiration.
Change in maximum temperatures: The change in maximum temperature to the
middle of the century shows a varied increase between 0.3 and 2.4 °C in RCP 4.5 and
from 1.1 to 3.4 °C under RCP 8.5. The higher increase is shown in the non-coastal
areas, with the greatest increases projected in the Maghreb region, the south of Nile
Valley, and the central and western parts of the Arab peninsula. Towards the end of
the century, the change shows an increase between 1 and 3 °C in RCP 4.5 and from
2 to 5 °C with RCP 8.5. The areas showing higher increases are almost the same as
in the scenarios of midcentury.
Change in minimum temperatures: The general change in annual average minimum temperatures to the middle of the century also shows a varied increase under
RCP 4.5 that goes from less than 1 °C at the Mediterranean coasts to more than
2 °C in the Sahara desert, the Atlantic mountains and Euphrates-Tigris basin. Under
RCP 8.5 the rise exceeds 1 °C almost everywhere in the Arab region and reaches
3–3.5 °C in some areas of the Sahara desert. The change of minimum temperatures
is clearly more evident towards the end of the century increasing between 1 and 3 °C
M. A. S. Abdel Monem and I. A. El Ghandour
2.2 At the Regional Level
According to the latest IPCC assessment, the Near East and North Africa (NENA)
region is one of the most vulnerable regions to climatic change. The Region is
predicted to become even hotter and dryer than what it already is. A temperature rising
up to 4 °C is expected by century’s end. Rainfall may decline up to 40% by 2050 (and
up to 60% in a 4 °C scenario), with an increase of severe drought and floods frequency
and intensity. Sea level rise of about 0.1–0.3 m is also expected by the year 2050,
augmenting seawater intrusion to coastal groundwater resources. It is anticipated that
such a climate change scenario would reduce crop yield up to 30%. The livelihoods of
a large segment of the region’s population, particularly those depending on small scale
rainfed agriculture, will be at great risk. The environment will be impacted as well
due to the anticipated increase of desertification, land degradation and biodiversity
losses. Ultimately, people migration will be accelerated.
The demand for a close observation on the impact of climate change on the
Region has materialized through the establishment of the ‘Regional Initiative for
the Assessment of the Impact of Climate Change on Water Resources and SocioEconomic Vulnerability in the Arab Region’ [6].
Within the RICCAR project, future climate change data are generated through
downscaling projections from three global circulation models, EC-EARTH, CNRM
-CM5, and GFDL-ESM, exercised on the region using the regional climate model
RCA4 to provide higher-resolution information (50 km). The two considered climate scenarios are based on selected Representative Concentration Pathways (RCP),
specifically RCP 4.5 (moderate-case scenario) and RCP 8.5 (worst-case scenario).
The projected climatic and hydrological variable considered (max and min temperature, and precipitation, runoff and evapotranspiration) are presented as the change
between the twenty-year periods of 2046–2065 (mid-century) and 2081–2100 (endcentury) with reference to the baseline period of 1986–2005. Here we highlight some
relevant findings for temperature, precipitation and evapotranspiration.
Change in maximum temperatures: The change in maximum temperature to the
middle of the century shows a varied increase between 0.3 and 2.4 °C in RCP 4.5 and
from 1.1 to 3.4 °C under RCP 8.5. The higher increase is shown in the non-coastal
areas, with the greatest increases projected in the Maghreb region, the south of Nile
Valley, and the central and western parts of the Arab peninsula. Towards the end of
the century, the change shows an increase between 1 and 3 °C in RCP 4.5 and from
2 to 5 °C with RCP 8.5. The areas showing higher increases are almost the same as
in the scenarios of midcentury.
Change in minimum temperatures: The general change in annual average minimum temperatures to the middle of the century also shows a varied increase under
RCP 4.5 that goes from less than 1 °C at the Mediterranean coasts to more than
2 °C in the Sahara desert, the Atlantic mountains and Euphrates-Tigris basin. Under
RCP 8.5 the rise exceeds 1 °C almost everywhere in the Arab region and reaches
3–3.5 °C in some areas of the Sahara desert. The change of minimum temperatures
is clearly more evident towards the end of the century increasing between 1 and 3 °C