More than 300 guests gathered in Esbjerg, Denmark, in early March to attend what was billed as the First Carbon Storage event.

They had been invited by energy companies Ineos and Wintershall Dea to witness the inauguration of the demonstration phase of Project Greensand, the world’s first cross-border offshore carbon dioxide storage development, which includes a crucial seismic monitoring component.

The Project Greensand pilot represents a first technology step in proving one method of storing large volumes of CO₂ beneath the ocean floor — not just offshore Denmark, but potentially worldwide.