Which action best fits sequester?

Isolating a substance so it stays apart from its surroundings. Exactly. Sequestration involves separation or isolation; it does not necessarily involve destruction.

Why is monitoring part of carbon storage?

It provides evidence about containment after injection. Exactly. Monitoring checks whether the injected carbon dioxide stays contained over time.

Where does the carbon dioxide stored at Sleipner come from?

It is separated from produced natural gas. Exactly. Sleipner's process separates carbon dioxide from the production stream before injecting it underground.

Today's connection

Set apart, then keep apart

When does moving something away count as solving the problem?

01 · Word

Sequester

Pronounced sih-KWES-ter

verb

To isolate or set something apart; in carbon storage, to keep carbon from entering or remaining in the atmosphere.

Examples

The archive sequestered damaged records while conservators assessed them.
The project aims to sequester carbon dioxide in rock formations underground.

Origin

From Latin sequestrare, to place in safekeeping, associated with a third party holding disputed property. The common thread across its uses is separation and custody.

02 · Idea

Storage is a continuing claim

Geological carbon storage works only if the injected carbon dioxide stays underground. Site selection and monitoring therefore belong to the same job as capture and injection.

The British Geological Survey describes monitoring methods that track underground carbon dioxide and look for possible leakage. The Sleipner project provides a long-running example of observing a storage site over time.

Carbon storage depends on keeping the gas underground.

Limits

Storage does not destroy carbon dioxide or make every associated activity emissions-free. Its climate benefit depends on how much stays stored and how much is emitted during capture, transport, and storage.

03 · Moment

Carbon dioxide below the North Sea

Sleipner field, Norwegian North Sea; storage began in 1996

At Sleipner, carbon dioxide separated from produced natural gas began being injected into a geological formation beneath the North Sea in 1996. Instead of releasing that separated gas to the atmosphere, the operation placed it in the Utsira formation.

Start: 1996
Formation: Utsira
Method: Injection beneath the seabed

The caveat

Sleipner captures carbon dioxide from a natural-gas stream, not directly from ambient air. Burning the natural gas that is sold still produces emissions, and storage sites vary in suitability.

Repeated seismic surveys have helped researchers track the carbon dioxide's movement within the storage formation.

The connection

Separation works only while the boundary continues to hold.