The Arab region is currently warming approximately twice as fast as the global average, and engineers designing its future nuclear power plants know this. An IAEA source mentions 15 reactors proposed by 2040; the official program currently published focuses notably on a first plant with two units, in a region where, under a very high emissions scenario, daily maxima exceeding 55°C are projected in certain Gulf zones by the end of the twenty-first century. The question concerns the physical conditions of cooling: will they still be met to ensure the operation of these reactors?
The Essentials
- The Middle East is warming twice as fast as the global average, with a possible increase of 5°C by the end of the century (UN News, May 2026).
- Saudi Arabia aims for 16 nuclear reactors by 2040, in a region that has virtually no permanent watercourses available for cooling.
- In France, reactors shut down temporarily as soon as river temperatures exceed 25-26°C, which illustrates the vulnerability of the classical nuclear cooling cycle.
- Barakah, the Emirates nuclear power plant cooled by seawater, already avoids 22.4 million tonnes of CO₂ annually and demonstrates that a technical alternative exists.
- Decision-makers must identify which energy systems remain thermodynamically viable when temperatures exceed the engineering limits of available technologies.
The Middle East Warms Faster Than the Rest of the Planet
According to the WMO, 2024 was the hottest year observed in the Arab region and its warming rate is approximately twice the global average. Under SSP5-8.5, an average increase of approximately 5.3°C is projected for the Arabian Peninsula by the end of the century, compared to 1981-2010. Under high emissions scenarios, daily maxima exceeding 55°C are projected in certain Gulf zones toward the end of the twenty-first century.
Heat constitutes an engineering constraint, not merely a matter of human comfort. Nuclear power plants, like all thermal power plants, produce heat that must be dissipated. This dissipation relies on a heat transfer fluid—river or seawater—that must remain sufficiently cold to absorb the residual heat from the fission cycle. As water warms, efficiency can decline and environmental limits may impose power reduction, operational adaptation, or in some cases, temporary shutdown.
Europe learned this lesson painfully during the heat waves of 2003 and 2022. In France, EDF must adjust production when specific temperature limits or temperature rise thresholds set for each site risk being exceeded; there is no general French rule at 25-26°C. These restrictions can reduce availability during hot episodes; they can complicate grid balance, but France’s annual consumption peaks occur primarily in winter. This mechanism, designed for a European temperate climate, illustrates a structural vulnerability that takes on another dimension in a region where 26°C is a January nighttime temperature.
The Thermal Limits of Classical Nuclear Energy: The French Example
France produces approximately 70% of its electricity through nuclear power, making it the world’s most dependent country on this energy source. France has 57 reactors in operation; many are cooled by rivers, but 15 are on the coast and others use the Gironde estuary. This historical choice, dictated by geography and freshwater availability, exposes the French fleet to a constraint that had not been fully anticipated in construction decisions made in the 1970s.
In summer 2022, heat and drought affected several sites, particularly on the Rhône, Garonne, and Gironde estuary; EDF and authorities applied adaptations and temporary exemptions according to each site. The combination of drought, which lowered river flows, and heat, which raised their temperature, created conditions that engineers qualify as a cooling constraint. The European grid compensated, but the episode illustrated vulnerability to extreme hydrometeorogical conditions whose probability should increase with climate change absent sufficient adaptations.
What the French experience teaches Saudi planners is simple to state: a reactor cooled by a water source whose temperature and flow vary with climate is a reactor whose availability depends on weather conditions. In a region without permanent rivers, this lesson takes on an even more direct form. Adapting infrastructure to climate already exceeds budgeted envelopes in several countries: integrating cooling costs into forty-year projections is not a secondary precaution.
Barakah Shows That a Path Exists, But at What Cost
One hundred sixty kilometers west of Abu Dhabi, the Barakah nuclear power plant has operated since 2021 with its four APR1400 reactors, designed by South Korea. Its distinguishing feature lies in its cooling method: water from the Persian Gulf, drawn directly from the sea, circulates in the cooling system before being discharged slightly warmed. Seawater is not subject to the same regulatory constraints as freshwater from rivers. Its volume is nearly unlimited. Its temperature, though high in the Gulf, remains technically compatible with current reactor operations.
Barakah’s balance sheet is tangible. The four units in service avoid 22.4 million tonnes of CO₂ emissions annually, equivalent to removing nine million cars from circulation according to the United Arab Emirates. In an economy still largely dependent on hydrocarbons, this represents a concrete contribution to decarbonizing the national electricity mix. The plant currently supplies approximately 25% of the Emirates’ electricity demand.
But Barakah is also a reference project whose constraints must be read honestly. Its construction took fifteen years. Its final cost exceeded initial estimates. It required massive knowledge transfer to Emirati engineers trained over a decade. And its coastal location, within reach of the Persian Gulf, is a geographic datum that Saudi Arabia cannot replicate identically for its sixteen envisaged reactors, some of which could potentially be located in interior zones or on less accessible coasts.
Seawater solves the volume and temperature problem, up to a point. The Persian Gulf itself is warming. In 2024, surface temperatures exceeding 35°C were measured in certain Gulf zones during summer months; such temperature can reduce margins and require specific design, but no universal technical threshold of 35°C applies to all nuclear equipment. Designers will need to define thermal margins adapted to climate projections and the specific characteristics of the Saudi site; a general comparison with temperate latitudes is not established.
Sixteen Reactors in Twenty Years: Saudi Arabia’s Bet Against Its Real Constraints
Saudi Arabia cooperates with or has requested technical data from suppliers in the United States, Russia, France, South Korea, and China; a safety agreement with the United States is documented, but the complete list of agreements signed with all these countries is not established by consulted sources. A proposal cited by the IAEA concerns 15 reactors by 2040; the current official published program is less precise and includes a first plant with two reactors. Saudi Arabia operates no commercial reactors; any construction pace comparison should be documented by international historical analysis and begin from a confirmed construction objective. By comparison, France built its 56 reactors over a twenty-five-year period with an already trained nuclear workforce and a mature engineering industry.
The program is designated SNAEP and mainly involves Saudi nuclear institutions, including K.A.CARE and the nuclear safety authority NRRC; SEZA is not established as co-pilot of the nuclear program. Its energy ambition is coherent with Vision 2030: diversifying the electricity mix to reduce hydrocarbon combustion within the country, thereby freeing additional volumes for export. Each barrel of oil not burned domestically for electricity production is a barrel sold on international markets at significantly more favorable prices.
This economic logic is sound. It does not resolve the thermal question. Saudi Arabia’s geographic situation implies that several envisaged nuclear sites could be located on the Red Sea or Persian Gulf coasts, or resort to closed cooling systems or air-cooled towers consuming large quantities of water in a country already extremely constrained in water resources. Desalination, which produces a significant portion of water consumed in the kingdom, is itself an extremely energy-intensive industry: coupling a nuclear program and a desalination program raises questions of large-scale systemic optimization.
UNIDIR and other bodies have emphasized the security and non-proliferation issues raised by such an ambitious nuclear program in a geopolitically tense region. Riyadh has not ratified the Additional Protocol of the International Atomic Energy Agency (IAEA), and the question of uranium enrichment remains a point of friction in its negotiations with Washington. These political dimensions interact with technical and climate challenges to define the real feasibility conditions of the program.
Technical Solutions Facing Climate Constraints
The thermal constraints of nuclear cooling are not a technical fatality. They are an engineering variable that existing solutions allow to address, at different costs and with different compromises depending on choices made.
Certain fourth-generation reactors, including some small modular reactors (SMRs), are designed with heat transfer fluids and thermodynamic cycles different from light water reactors, potentially allowing dry cooling or reduced water dependence. Some models use helium gas as a heat transfer medium and do not need water for primary cooling. Others use molten salt or liquid sodium. These technologies can significantly reduce water dependence, but dry cooling remains sensitive to ambient air temperature. Several projects are in industrial demonstration phases in the United States, Canada, China, and the United Kingdom, with first commercial deliveries expected in the 2030s.
Companies like NuScale Power in the United States, Terrestrial Energy in Canada, and Kairos Power are developing these architectures. China is advancing with the HTR-PM reactor, a high-temperature gas-cooled reactor whose first modules started at Shidaowan in 2023. Closed cooling systems through towers are already widely deployed; the maturity level depends on the specific advanced technology targeted.
Dry cooling towers, already used in some plants in arid zones, offer another path. They do not need watercourses and function through air convection. Their disadvantage is lower efficiency in hot weather, but hybrid architectures combining wet and dry cooling allow optimization of the thermal balance according to seasons. Concentrated solar power plants in Saudi Arabia and the Emirates already use variants of this system in analogous climate conditions.
The question of how to make low-carbon ambition and climate adaptation coexist is now part of all serious energy policies: Saudi Arabia’s nuclear program illustrates it from a particularly concrete angle.
Physics Dictates Energy Choices at the 2050 Horizon
This constraint extends beyond nuclear alone and concerns the entire energy architecture of the region. In a Middle East 5°C warmer, decision-makers will need to determine which production systems remain thermodynamically viable at acceptable cost.
Natural gas power plants, which currently provide much of Saudi Arabia’s electricity, also suffer from heat. The efficiency of gas turbines declines when inlet air temperature exceeds design nominal values. In certain Gulf zones, plants already operate at efficiencies below their original specifications during summer months. Additional warming of several degrees would worsen this phenomenon.
Photovoltaic solar energy is, on this point, less vulnerable. Panels lose efficiency in extreme heat, approximately 0.4% of power per degree above 25°C according to manufacturer data, but this degradation remains limited compared to constraints suffered by thermal cycles. Saudi Arabia benefits from among the world’s highest solar insolation, and projects like NEOM or the Al-Shuaiba solar park show that the kingdom takes this resource seriously. The difficulty is storage: a heavily solar system requires significant flexibility and storage resources, some of whose long-duration solutions must still be widely deployed; it does not depend solely on batteries and current technologies are already used at large scale.
The complementarity between nuclear and renewables takes on an operational meaning here. Solar covers daytime needs with low marginal cost. Nuclear or other dispatchable sources ensure nighttime baseload and supply security in winter or during cloudy episodes. This combination, provided that deployed reactors are adapted to local climate conditions, could constitute a coherent mix for a region undergoing profound transition.
The decision window is narrow. Reactors built today will be in service in 2060 or 2070. Their cooling systems must be designed with relevant climate projections in mind during the installation’s operating life, according to site and regulatory requirements. This means choosing technologies and sites while anticipating conditions that do not yet exist.
Saudi Arabia is studying and developing a nuclear program, but it does not yet operate sixteen reactors. Historical objectives have mentioned up to sixteen reactors, while a recent IAEA publication mentions a proposal of fifteen reactors by 2040. Nuclear cooperation agreements and commercial negotiations with constructors may not fully integrate this constraint in their clauses.
A signal to watch will be publication of thermal feasibility studies for selected sites. They should be made public and, where national law requires, be attached to the file submitted to the national safety authority, not the IAEA as the licensing authority. If these studies integrate climate assumptions at a 2060 horizon, Saudi planners will have shown they take the constraint seriously. If they account only for historical or current climate, they risk underestimating future vulnerability to droughts, heat, and cooling constraints. The parallel with decisions to plan withdrawal from environments that have become unmanageable imposes itself: in both cases, deciding too late costs infinitely more than deciding too early.
The Middle East’s nuclear program is not condemned by climate change. But pressurized water reactors can meet climate constraints if their cooling design and margins are adapted to site conditions; the extent of adaptations depends on the project. The coming period, during which contracts will be signed and first concrete poured, will determine whether Saudi Arabia’s future reactors will be reliable assets in 2060 or installations constrained to operate below nominal capacity precisely when air-conditioning demand reaches its peaks.
Sources
- UN News, May 2026, Climate Warming in the Middle East
- WMO State of Arab Climate Report 2024, World Meteorological Organization
- UNIDIR, report July 2026, Nuclear Energy and Regional Security in the Middle East
- IEA World Energy Investment 2026, International Energy Agency
- Emirates Nuclear Energy Corporation (ENEC), Barakah Production Data