A section of the Lagos–Calabar Coastal Highway under constrution could triger the release of more than 3.5 million tonnes of greenhouse gases and cause climate damage valued at nearly N785 billion, according to a new scientific assessment that warns the project would destroy the carbon-absorbing capacity of the Stubbs Creek Forest Reserve.
The study, conducted by Joel Benson, a greenhouse gas analyst and researcher at the University of Abuja, assessed the climate implications of the highway using satellite-based geospatial data and internationally recognised greenhouse gas accounting frameworks.
According to the findings, constructing the highway through the reserve would result in a net emission of 3,511,562 tonnes of carbon dioxide equivalent (tCO₂e) over a 20-year accounting period, driven by forest clearance, biomass removal and soil disturbance.
“This outcome reflects the transfer of a carbon-rich natural system into a net emitter through vegetation removal and soil disturbance. This observation aligns with general trends reported for tropical forest loss, where disturbances and deforestation accelerate carbon fluxes toward emission rather than sequestration,” the study stated.
The assessment showed that carbon dioxide was the dominant greenhouse gas, contributing 3,510,847 tCO₂e, largely from the removal of forest biomass and the loss of soil organic carbon. Nitrous oxide contributed 715 tCO₂e, released as forest clearing disrupted nitrogen cycles in the soil.
Although emitted in smaller quantities, nitrous oxide is 265 times more potent than carbon dioxide in terms of global warming potential, the report noted.
Stubbs Creek Forest Reserve is a legally gazetted forest reserve, established in 1930 for conservation and ecological protection. Located across Ibeno, Eket, Esit Eket and Mbo local government areas, it is the largest forest reserve in Akwa Ibom State and a key ecosystem in the Niger Delta.
However, the study noted that the reserve has suffered decades of degradation. Dense forest cover declined from 63.50 square kilometres in 1993 to 28.22 square kilometres by 2013, raising concerns that any further disturbance could lead to its complete loss.
“The reserve is effectively lost with the implementation of the project,” the report said, referring to the proposed highway alignment.
Climate damage put at N785bn
Beyond emissions, the study placed a monetary value on the climate damage associated with the proposed highway route.
Using a carbon price of $158 per tonne of CO₂ equivalent, the total emissions were valued at $554.8 million, equivalent to approximately N785 billion at the Central Bank of Nigeria’s exchange rate as of January 2026.
“The magnitude of the economic cost captured through this valuation positions SCFR as a strategic asset for climate mitigation, whose protection is critical for maintaining local, national, regional, and global climate stability, and therefore must be safeguarded at all cost,” the study said.
According to the study, the analysis was based on data from IPCC climate zones, FAO Global Ecological Zones, and the Harmonised World Soil Database (HWSD 2.0). Emissions were estimated using the Environmental Externalities Accounting Framework, applying IPCC Fifth Assessment Report (AR5) global warming potential values over a 100-year timeframe.
The study explained that forest loss would occur during a one-year implementation phase, followed by a 19-year period during which emissions would continue as disturbed soils release carbon and removed biomass decomposes.
“This implies that the reserve is effectively lost with the implementation of the project,” the report stated.
The study warned that the loss of Stubbs Creek Forest Reserve would weaken the natural resilience of the Niger Delta, a low-lying region already vulnerable to flooding, coastal erosion and sea-level rise. It noted that forests in the region provide natural protection against climate extremes while supporting fisheries and agriculture.
The Lagos–Calabar Coastal Highway and recommendations
The Lagos–Calabar Coastal Highway is a flagship federal infrastructure project promoted for its economic and transport benefits. However, the study said the climate cost of routing the road through a protected forest has not been adequately considered.
Stubbs Creek Forest Reserve was gazetted in 1930 for ecological protection, yet the proposed route would require clearing what remains of its dense forest cover. The study did not identify any publicly available justification explaining why an alternative alignment outside the reserve was not adopted.
The report also raises questions about who approved the current route and the basis on which the environmental risks were weighed against the project’s anticipated benefits.
Beyond domestic approvals, the findings appear to conflict with Nigeria’s commitments under the Paris Agreement, which require the country to reduce greenhouse gas emissions and protect natural carbon sinks such as forests. The study argues that converting Stubbs Creek into a net source of emissions undermines those commitments.
It recommended that the highway be rerouted well away from Stubbs Creek Forest Reserve and that greenhouse gas emissions and their economic value be fully integrated into infrastructure planning and appraisal.
“This analysis is intended to inform policymakers, government authorities, environmental planners, and the public that the true cost of the intervention is not only infrastructural or financial but fundamentally climatic, with potentially irreversible consequences if ignored.
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“The magnitude of the economic cost captured through this valuation positions SCFR as a strategic asset for climate mitigation, whose protection is critical for maintaining local, national, regional, and global climate stability, and therefore must be safeguarded at all cost,” the report stated.
A coalition of 70 civil society organisations had raised the alarm over the planned routing of the coastal highway through the forest reserve.
In a recent statement, Policy Alert said evidence from the Federal Ministry of Environment shows that the Environmental and Social Impact Assessment (ESIA) for the section of the highway passing through Stubbs Creek only commenced in January 2026, months after official approvals had been granted and public announcements made regarding the project’s alignment.
“Approving or advancing the project before completing a comprehensive ESIA undermines the legal intent of the Act and raises serious questions about transparency and due process,” the CSO said.
