Aden

With its strategic location overlooking the sea, Aden is among the most politically and economically significant governorates in Yemen. Its capital, Aden city, is the second most populous city of the country, with around 1.2 million residents, of 24% IDPs, migrants and refugees. [i]  Aden is also home to Yemen’s most important ports and oil refineries, making it an important business hub. Environmental challenges in the governorate mostly relate to the governance of natural resources such as water and fish stocks, the accumulation of waste in urban areas, and climate-induced risks such as floods and sea–level rise, all of which exert additional pressure on Aden’s population. 

With its strategic location overlooking the sea, Aden is among the most politically and economically significant governorates in Yemen. Its capital, Aden city, is the second most populous city of the country, with around 1.2 million residents, of which around 279,144 are IDPs and nearly 20,710 are migrants and refugees, mainly from Somalia, Eritrea and Ethiopia.[ii] Aden is also home to one of Yemen’s most important ports, which was built up under British colonial rule, as well as one of the country’s main oil refineries, making it an important economic centre. For two decades, Aden was the political capital of what then was called the People’s Democratic Republic of Yemen until its unification with the Yemen Arab Republic in 1990.[iii]

In early 2015, President Hadi declared Aden as the interim capital after Sana’a was captured by Ansar Allah (Houthi) forces. Shortly afterwards, Aden became a major faultline of clashes between the Houthi rebels, pro-Hadi forces, and militias of the Southern Movement, who wrangled over control of the city. While Houthi control of the city was reduced over the course of 2015, tensions between the Internationally Recognized Government of Yemen (IRGY) and the Southern Movement later formalised as the Southern Transitional Council (STC) continued to intensify. Between 2018 and 2019, several rounds of armed confrontations reshaped the balance of power, ultimately enabling the STC to consolidate its influence in the city. As a result, Aden effectively became the STC’s political and administrative power centre until January 2026.
Moreover, the governorate of Aden has remained a stronghold of Al-Qaeda in the Arabian Peninsula (AQAP) and the Islamic State of Iraq and the Levant – Yemen Province (ISIL-YP). The fragmentation of political authority and governing institutions in Aden has also led to the increased political importance of tribal loyalties and kinship ties.[iv] In May and June 2025, recurrent electricity shortages and rising socio-economic pressures on basic services, including water, triggered a new wave of demonstrations led by women in Aden, prompting a dual response of increased fuel allocations to power stations and the deployment of STC security and female militia units to restrict protest activity.[v]

The aftermath of the STC led “Promising Future – Dec 2025” operation in Wadi Hadramout and Al‑Mahra, where Southern forces rapidly advanced before being pushed back under Saudi‑supervised arrangements, has triggered significant political and security shifts in Aden. For years, Aden functioned as the principal power base of the STC, but the contested announcement of the STC’s dissolution in early January 2026 created a new configuration of authority on the ground. In the days that followed, the PLC initiated a series of measures that reshaped the city’s security landscape, beginning with the replacement of the Security Belt Forces with the Southern Giants Brigades, who later relinquished these positions to the Nation’s Shield Forces, a formation directly aligned with the PLC’s head. This restructuring was accompanied by other moves, including PLC’s order to close and confiscate STC administrative headquarters across the city, signalling a systematic effort to dismantle the STC’s institutional presence in Aden.

Although these steps did not escalate into open armed confrontation, the political tensions in Aden have risen markedly. STC supporters have regularly mobilised in protest, rejecting both the dissolution announcement and the broader political direction of the current government. The streets in Aden reflect a widespread frustration and a sense of disenfranchisement among large segments of the southern population. As a result, Aden now faces acute uncertainty, with shifting security alignments, weakened social cohesion, and mounting public tensions shaping the city’s landscape.

Topographically, Aden governorate is constituted of a mountainous region and a coastal plateau. The flat coastal area is characterised by sand dunes. Its two wadies, Wadi Al Kabeer and Wadi Al Sageer, surround the Tuban Delta, an agricultural area west of Aden, where farmers grow subsistence crops such as sorghum, millet, wheat, and maize, as well as cash crops such as fruits or cotton. The 21 islands and rocky heads of Aden are surrounded by scattered coral reefs and serve as fishing grounds.[vi] Fishing has traditionally been one of the main livelihoods at the Gulf of Aden coastline.

Aden’s water supply mainly relies on groundwater from about 30 reservoirs, extracted through close to 100 water wells, which are distributed over three main fields; Bir Nasser (46), and Bir Ahmed (29)Manaserah (16).[vii] While the Bir Nasser well field is geographically located in Lahj governorate, it is reported to be effectively under the command of Aden’s administration.[viii] As of 2020, this water collection, treatment, and distribution network extended to over 1,100km and reached about 86% of Aden city’s population. The system has been largely operational since 2015, but there have been significant damages to pumps and treatment facilities. [ix]

Its location at the Gulf provides Aden with hot, arid climate, with average yearly rainfall rates between 10-100 mm. Over the course of the year, temperatures typically vary from 24°C to 35°C. Over the past decades, average yearly temperatures have been following an upward trend, which is expected to continue according to projections under CMIP6 SSP2-4.5 (see fig. 1). Annual rainfall in Aden governorate has fluctuated significantly and does not show any clear trend according to available historical climate data. However, projections forecast an intensified rainfall trend in Aden, with the cross-year average of annual rainfall rates approaching 200 mm (see fig. 2), and average rainfall during the year’s wettest days expected to increase by about 40 mm until the year 2100.[x]

The most important climate- and environment-related security risks in Aden lie in the degradation of marine resources and coastal landscapes through unsustainable fishing practices, sea-level rise, and flooding, as well as the impacts that this will have on the livelihoods of fishers. Tensions and insecurity are also driven by the pollution and deterioration of groundwater and challenges in providing water supply to the governorate’s large population. Additional grievances are caused by pollution through war remnants, as well as wastewater and solid waste, particularly in Aden City, and could contribute to additional dissatisfaction and unrest among Aden’s population.

• Rainfall and flash floods: Aden is known for its dry summers and general lack of rain, but in recent years, it has repeatedly experienced torrential downpours leading to flash floods. In April 2020, a flash flood in Aden resulted in at least 7 deaths, numerous injuries, and large-scale damage to houses and infrastructure,[xi] and the governorate was again affected by floods in the following year.[xii] The Al Burayqah and Dar Sad districts are highlighted due to their high flooding risk.[xiii] In focus group discussions (FGDs) conducted by the European Institute of Peace in 2023, participants from Aden also highlighted that such floods, paired with a lack of maintenance, are leading to the deterioration of irrigation facilities and contribute to soil erosion[xiv] Such effects, alongside the impacts of the conflict and government negligence, have left Aden with a weak infrastructure and a worn-out sewage and waste management system[xv]With heavy rainfall events projected to increase further, these risks will likely become more pressing in the years to come. This may have implications for stability in the governorate, with losses suffered from such events adding to existing grievances. These insights are reflected in our latest survey results showing that 46 percent perceive conflicts related to the environment and natural resources.
• Marine degradation and sea level rise: Unsustainable fishing practices are exerting significant pressure on marine species inhabiting Aden’s coast. Already now, Yemen’s fish stocks are harvested at levels above the Maximum Sustainable Yield, with illegal fishing and coral collection in the Gulf of Aden exacerbating the trend.[xvi] Climate-induced pressures, particularly sea level rise, add to this risk. Government projections foresee the sea level at Aden’s coast to rise between 0.14 and 0.25 metres by 2050, and 0.3-0.54 metres by 2100, compared to a 2008 baseline. This would translate to an inundated area of up to 45 km², equating to six per cent of the governorate’s surface. The airport, located in the coastal area, is expected to be particularly impacted. Aden’s ecosystems at the sandy coastline, wetlands, and underground aquifers are highly susceptible to the effects of sea level rise, which include land erosion and more frequent floods, with the storm-prone area expected to extend to most of the governorate’s coastal plain.[xvii] These environmental risks are further compounded by the deteriorating security situation in the Red Sea, where sustained Houthi attacks on maritime traffic since 2023 have heightened the strategic importance of Aden’s port and increased its exposure to regional maritime tensions. Provided the importance of fishing for Aden’s economy, this trend is likely to further destabilise the governorate, contributing to decreases or losses of livelihood and hence dissatisfaction among the population. It could also contribute to tensions and direct confrontations between fishers about fishing grounds, as well as grievances relating to forced displacement due to the depletion or complete loss of housing and livelihoods in concerned areas.
• Water availability and access: The governorate is also facing major issues with ensuring supply of clean water for drinking and household activities, as well as water to feed its agriculture. The prognosed SLR levels are likely to cause saltwater intrusion into aquifers, which will render boreholes increasingly brackish and unproductive. Due to ongoing unregulated and excessive groundwater extraction, the main water supply areas of Bir Ahmed and Bir Naser are expected to shift from low to high vulnerability, with brackish conditions projected by the end of the century. [xviii] The governorate’s important aquifer Bir Ahmed, whose extraction levels are already exceeding its recharge rate, has been found highly vulnerable to such consequences.[xix] In 2022, the annual inflow from the northern highlands was estimated at 125 MCM, yet only 15% reached the lower delta near Aden, limiting freshwater availability, altering soil conditions, and reinforcing reliance on groundwater for farming and daily use.[xx] [xxi] [xxii] Moreover, Aden’s water security is highly fragile because the city depends on groundwater sources located in neighbouring governorates especially the Abyan basin and the Bir Nasser well field in Lahj over which it has limited control. This external dependence, combined with recurring political friction with Abyan, leaves Aden vulnerable to supply disruptions and deepens inter‑governorate tensions. This degradation of natural resources poses security risks, with water, land, energy, and other resources already being a driver of competition and tensions between the two governorates. [xxiii]
• Waste and pollution: Ensuring waste and wastewater management for Aden’s large population is a difficult task, and the war has put additional pressure on existing infrastructure. Aden hosts several major dumpsites, including a landfill close to Aden city centre, which is estimated to receive around 650 tons of waste per day.[xxiv] More recent observations indicate that Aden’s waste generation has increased substantially; according to a CCIF representative, the city’s daily waste production grew from approximately 670 tons in 2011 to over 1,400 tons in 2024.[xxv] Located on porous and permeable sediments, these dumpsites risk the transmission of leachate into underlying groundwater resources.[xxvi] Meanwhile, according to an assessment conducted in 2015, out of a total fleet of 118 waste collection trucks in Aden, only 20 were operational.[xxvii] Since then, some improvements have been initiated, including Japan’s donation of 13 new garbage trucks[xxviii] and Kuwait’s funding for the construction of the Al-Arish Wastewater Pumping Station[xxix]; but these efforts have still not been sufficient to substantially improve waste management services in the city. Solid waste, including explosive remnants of war[xxx], and wastewater are accumulating in the streets, contaminating drinking water, and often entering the sea. Rainfall, especially where it results in floods, aggravates this problem by washing pollutants towards the coast. The heavy pollution of Aden’s marine environment is exacerbated further by desalination plants, refineries, oil spills, and industrial activities, which have shown to contribute to the concentration of heavy metals and other toxic substances around the Port[xxxi] Next to the potential harm that this may cause to marine ecosystems and the larger environment[xxxii] it also risks impeding fisheries and affiliated livelihoods[xxiii] hence contributing to grievances and tensions around natural resources and sources of livelihood.

Potential entry points to tackle these challenges while preventing and resolving tensions relating to environmental issues are:

• Promote the transition from traditional surface irrigation to drip irrigation. This can be complemented by awareness-raising campaigns on water-saving practices, the introduction of drought-and salt-tolerant crop varieties, and the rehabilitation of wetlands. In the longer term, options such as greywater reuse, rehabilitation of the Al-Tawelah Tanks, sustainable water use management and nature-based solutions such as green tree planting and mangrove cultivation can support water security and reduce pressure on shared resources.
• Supporting cooperative and locally-led water and waste management, e.g. developing joint water management plans, establishing community-level water management committees, or supporting the development of water sharing agreements between communities. This should be done in coordination with the responsible national and local authorities (e.g. Ministry of Local Administration (MoLA), National Water Resources Authority (NWRA), Ministry of Water and Environment (MWE), local corporations), as well as local tribal and religious leaders. Groups which are typically excluded from political decisions, such as women or youth, can play a major role such initiatives.
• Raise awareness about the risks implied in sea level rise, and support communal adaptation planning to prevent tensions arising in the context of displacement and loss of livelihoods induced by sea level rise.
• Promoting more sustainable fishing practices, including through leveraging the legal instruments promoted by the Regional Organization for the Conservation of the Environment of the Red Sea & Gulf of Aden (PERSGA).
• Supporting the build-up of local conflict resolution mechanisms (e.g. committees, councils, individual mediators) and developing the capacity of existing mechanisms to deal with resource-related conflicts (land tenure, water use, etc.).
• Enhancing resilience through livelihood diversification measures, for instance, by creating additional employment opportunities and training programmes in the waste management or wastewater treatment sectors.