Nature-Based Solutions as a Decarbonization Strategy

Abstract In the context of practical climate change action, cost effective measures to tackle emissions, either directly or through carbon sequestration, are urgently needed. This paper introduces a novel nature-based solution for wastewater treatment that also offers significant carbon sequestration benefits, and provides considerable savings over conventional approaches. This innovative solution was proposed for an unconventional gas field Mega-Project within the Middle East. As part of the sustainability requirements of the Mega-Project, a new screening tool was developed to rapidly appraise over 370 initiatives, focusing on sustainability and decarbonization across the construction and operations phase of the project. Key themes identified included water conservation, energy efficiency, and renewable power production. A resulting comprehensive circular sustainability strategy was developed, utilizing renewables for water heating, composting for food waste, treating sanitary waste and process wastewaters via a Reed Bed, and a native tree plantation area to utilize the treated water and compost. The solution aligns with the green/circular economy ideals and offers significant multiple benefits. The proposed Reed Bed design consists of 12 × 1,000 m2 of Vertical Flow Wetlands cells, and 3 × 9,000 m2 of Surface Flow Wetlands cells. Once operational, this nature-based solution will facilitate the reclamation of over 16 million m3 of treated water, to be used for tree plantations. The 1,000 hectares of plantations would additionally be fenced off to facilitate natural rangeland regeneration and as a barrier to increasing desertification. Based on this proposal, it was estimated that the combination of the fenced rangeland, plantations, and reed beds would sequester approximately 1.25 MtCO2 over 25 years. This initiative additionally presents a biodiversity value of over US $400 million. Further significant benefits of the scheme includes a site footprint reduction of over 800,000 m2 and a cost saving of around US $100 million. Besides these economic and environmental benefits, reed beds provide a host of other sustainability benefits. This project will result in a strategic shift within the client organization resulting in the widespread adoption of nature-based solutions to replace conventional wastewater treatment and disposal, representing significant organizational decarbonization benefits. All of the Client's processing facilities will be evaluated for the suitability of deploying similar reed bed based solutions. This paper presents the first in-country and in-company deployment of a novel constructed wetland systems and marks a strategic shift for the oil and gas industry. We demonstrate how the adoption of nature-based solutions over conventional wastewater treatment offers significant decarbonization benefits, cost savings, and environmental advantages. The combined benefits present a new pragmatic option for the industry's toolbox of decarbonization and waste treatment solutions.