Arab Climate Change Assessment Released

SMHI joined UN-ESCWA (UN Economic and Social Commission for Western Asia) and the League of Arab States (LAS) in releasing the Arab Climate Change Assessment Report in Beirut on September 26. This was a big moment for the Arab region as this is the first time that a climate change assessment has been done for the entire region.

The assessment report is the main result from the long-going cooperation of partners within the RICCAR Project (Regional Initiative for the Assessment of Climate Change Impacts on Water Resources and Socio-Economic Vulnerability in the Arab Region). It provides a consistent climate change assessment across 21 of the 22 Arab countries (Comoros is excluded due to its southern latitude). LAS has long strived after such a study as results from this region in all IPCC (IPCC – Intergovernmental Panel on Climate Change) reports to date have been based on unconnected studies over different sub‑regions.

Important role for SMHI in the RICCAR Project

SMHI is a core partner in the RICCAR Project that produced the Arab Climate Change Assessment Report. SIDA (Swedish International Development Agency) and GIZ (Deutsche Gesellschaft für Internationale Zusammenarbeit – German Cooperation) provided support for the project that officially began in 2011. SMHI performed both the regional climate modelling (RCM) and the regional hydrological modelling (RHM) work done over the entire region, which are key components of the report.

SMHI is a core partner in the RICCAR Project that produced the Arab Climate Change Assessment Report.

– Given SMHI’s expertise in both climate modelling and hydrological modelling, together with our computing capability and ability to manage large datasets, it was natural that SMHI had a major role in these aspects of the project. Regional scientists with more in-depth knowledge on regional processes were key partners in the cooperation, providing critical inputs to the modelling and analysis work done, says Phil Graham, project leader for RICCAR at SMHI, International Projects Manager and Senior Researcher.

Both the RCA climate model from the Rossby Centre and the HYPE hydrological modelfrom the Hydrological Research Unit were used. An additional hydrological model was also used – the VIC model – to help assess robustness of results. At an early stage, the RCM efforts within RICCAR led to establishing the MENA RCM modelling domain within CORDEX (Coordinated Regional Climate Downscaling Experiment), which prescribes international standards for RCM research cooperation.

Changing climate will affect the Arab region

The assessment has confirmed that the Arab Region stands to be strongly affected by changing climate. According to results from the RCA Model, increasing temperatures over the coming century will likely be more pronounced during summer months for many areas.

A big moment for the Arab region.

– Temperature extremes, such as the number of days exceeding 40ºC, show larger increases than mean temperature change. Although the projected change in precipitation varies across the region, there are many areas that show decreasing precipitation. This will of course have a strong impact on water resources. According to results from the HYPE Model, even areas that experience some increase in precipitation may still experience decreases in river flow due to increasing evapotranspiration.

All of these effects are shown to be much more severe for the case of higher greenhouse gas emissions (RCP 8.5) versus a milder emissions case (RCP 4.5) – RCPs (Representative Concentration Pathways are the emissions scenarios used internationally for creating climate projections).

– It has been challenging in many regards to work in this region. The climate is highly variable and the scarcity of water resources is a well-established fact. Our models are challenged by these conditions, which is exasperated by the lack of observed climate and water data. You simply have to do the best you can with the knowledge and resources available. On top of that, you also have the dynamics of change that swept through the region in recent years and ongoing crises with devastating humanitarian impacts. And yet our regional partners continue their work as they know that a changing climate is a factor that will affect them, regardless of changes in social constructs, Phil continues.

The High Level Conference on Climate Change Assessment

Although ensuing crises in the Arab region have at times affected progress, the assessment report was well-received at the High Level Conference on Climate Change Assessment in the Arab Region in Beirut. More than 180 participants representing most Arab countries, UN agencies active in the region and WMO (World Meteorological Organization) attended the three day event.

SMHI’s project leader Phil Graham (to the right) and Joel Dahné (to the left) were present in Beirut.

– It is impressive how positive and engaged all the assembled regional actors are. We have had many interesting discussions and I expect the results will have a long life as the countries look more deeply on how their areas will be affected. They will use the RICCAR projections to further study impacts on sub-regional, national and river basin levels. We anticipate a potential RICCAR II initiative as there is great need, both on further development of climate information and training in climate analyses for regional scientists, says Phil Graham.