PORE-SPACE OWNERSHIP AND SITE-ASSEMBLY LAWS

Geological storage requires legal rights to the underground rock spaces that receive carbon dioxide. A pore-space law states who owns those spaces, how the interest may be sold or leased and how it relates to surface and mineral rights. A site-assembly procedure, often called unitisation or amalgamation, can combine the many parcels above one storage reservoir after a stated consent threshold is met and compensation is provided to non-consenting owners. The lever clarifies property and assembles a usable site. It does not establish injection safety, long-term liability or ownership of the stored carbon, which require separate rules.

Ownership may follow the surface estate, mineral estate or state, and the choice affects bargaining power and compensation. Site assembly needs a credible consent threshold, advance notice, an independent hearing, access to valuation evidence and a lawful way to determine and pay just compensation before compulsory use begins. The law needs to address severed rights, Indigenous and public land, mineral development, reservoir migration, title recording and appeals. Constitutional property protections differ between jurisdictions, so copying oil and gas unitisation without testing whether injected carbon creates a compensable occupation can make the mechanism unusable.

Clear ownership gives developers and lenders a chain of title for the storage reservoir. Voluntary leases can then be negotiated against known rights, while a constitutionally sound assembly process can prevent a small number of holdouts from blocking a reservoir that crosses many parcels. Compensation or royalties can give landowners a direct stake in the project. The effect is strongest where fragmented ownership is the remaining obstacle, since the law does not prove geological suitability or replace storage permits and infrastructure.

A statutory ownership choice can transfer value and prompt litigation. Weak notice, low consent thresholds or compensation decided after occupation can violate property rights and delay projects for years. A generous holdout position can also make assembly impractical. Conflicts between storage, minerals, groundwater and Indigenous rights may persist despite clear pore-space title. Developers may mistake an assembly order for proof that the reservoir is safe or socially accepted.

Evaluation should examine voluntary consent rates, time and cost required to assemble sites, compensation, objections, appeals and constitutional challenges. Comparisons between projected and actual reservoir boundaries can reveal whether the legal unit matches the geology. Persistent disputes should inform thresholds, valuation rules and hearing protections before more sites rely on the procedure.

Property owners, Indigenous rights-holders, mineral owners and prospective storage operators should test how title, valuation and compulsory inclusion work in realistic parcels. Regulators, courts, land registries and constitutional experts need a workable hearing and appeal process. Communities should be able to distinguish property assembly from the separate decision on environmental safety and project approval.

National legislatures can define property rights and compulsory site assembly where land law is national. States or regions can do so where constitutions devolve property, mineral or storage law, as in the United States. Either level may operate independently, although storage and environmental regulators must align their proceedings. International and supranational rules may influence cross-border storage, but they do not normally determine title to domestic onshore pore space. Municipalities, companies and philanthropies cannot bind non-consenting owners through general law.