Offshore carbon sequestration using renewable ocean energy as a means to meet the Paris Agreement
Date
2026
Authors
Moffat, Leslie
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Abstract
The Intergovernmental Panel on Climate Change has identified the need for negative emission technologies to limit the rise in Global Mean Surface Air Temperature (GMSAT) to 2.0°C above pre-industrial temperatures. Coupled Ocean Thermal Energy Conversion (OTEC) and Direct Air Carbon Capture and Storage (DACCS) in marine environments could create a renewable energy powered method of sequestering atmospheric CO2 to prevent surpassing, or limit overshoot, of this threshold. This research identifies the magnitude of coupled deployment required to prevent surpassing the 1.5°C and 2.0°C Paris Agreement GMSAT thresholds. Through a series of sensitivity experiments, using the University of Victoria Earth System Climate Model, the effects of the initial climate state, OTEC cold water intake depth, and deployment timeline are explored to maximize the efficiency of coupled OTEC and DACCS. Potential locations for coupled deployment are identified and used to estimate the magnitude of GMSAT reductions. Using estimates of the transient climate response to emissions and carbon emissions diagnosed from representative concentration pathways, target OTEC power production estimates were determined. By current DACCS technology standards, it was found that under low emissions scenarios, no action is required to remain below either GMSAT threshold. The potential to satisfy required power production under moderate emission scenarios varied depending on the timeline. At no point could either GMSAT threshold goal be achieved under high emission scenarios. Finally, the likelihood of remaining below the 1.5°C and 2.0°C GMSAT thresholds was significantly improved assuming an increase in the energy efficiency of DACCS technology.
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Keywords
Ocean Thermal Energy Conversion (OTEC), Direct Air Carbon Capture and Storage (DACCS), Climate modelling, UVic Earth System Climate Model, Offshore carbon dioxide sequestration, Global Mean Surface Air Temperature (GMSAT), Paris Agreement, Transient Climate Response to Emissions (TCRE), Climate change mitigation, Renewbale energy