Switching from fossil fuels to renewable energy is key to international energy transition efforts and the move
toward net zero. For many nations, this requires decommissioning of hundreds of oil and gas infrastructure in the marine environment. Current international, regional and national legislation largely dictates that structures must
be completely removed at end-of-life although, increasingly, alternative decommissioning options are being
promoted and implemented. Yet, a paucity of real-world case studies describing the impacts of decommissioning
on the environment make decision-making with respect to which option(s) might be optimal for meeting in�ternational and regional strategic environmental targets challenging. To address this gap, we draw together
international expertise and judgment from marine environmental scientists on marine artificial structures as an
alternative source of evidence that explores how different decommissioning options might ameliorate pressures
that drive environmental status toward (or away) from environmental objectives. Synthesis reveals that for 37
United Nations and Oslo-Paris Commissions (OSPAR) global and regional environmental targets, experts consider
repurposing or abandoning individual structures, or abandoning multiple structures across a region, as the op�tions that would most strongly contribute toward targets. This collective view suggests complete removal may
not be best for the environment or society. However, different decommissioning options act in different ways and
make variable contributions toward environmental targets, such that policy makers and managers would likely
need to prioritise some targets over others considering political, social, economic, and ecological contexts.
Current policy may not result in optimal outcomes for the environment or society
