Researchers have proposed a radical method to slash carbon dioxide levels in the atmosphere.

A new study suggests liquid CO2 could be injected beneath the seafloor, where it could form hydrates that create a ‘cap’ that prevents it from leaking into the ocean.

The scientists in China simulated the method under 22 different scenarios, with variations in pressure and temperature to mimic real world conditions.

Researchers have proposed a radical method to slash carbon dioxide levels in the atmosphere. A new study suggests liquid CO2 could be injected beneath the seafloor, where it could form hydrates that create a ‘cap’ that prevents it from leaking into the ocean

Carbon sequestration, or the process of capturing carbon from the atmosphere and storing it, is one of many methods scientists have turned to in hopes to keep global warming from getting out of hand.

This isn’t the first time it’s been suggested that carbon can be injected into deep-sea sediments, the researchers explain in the new study published to the journal Science Advances.

But, it could finally help to overcome some of the challenges faced by previous research.

‘CO2’s buoyancy has posed problems, as it can escape back into the ocean and atmosphere through pathways within the sediments,’ the authors explain.

The new study builds on previous investigations that have shown liquid CO2 under high pressure and low temperatures spurs the production of hydrates.

Under certain conditions, these hydrates create an impermeable barrier to keep the CO2 in its place, they say.

‘The results show that low buoyancy and high viscosity slow down the ascending plume and the forming of the hydrate cap effectively reduces permeability and finally becomes an impermeable seal,’ the authors write in the study, ‘thus limiting the movement of CO2 toward the seafloor.’

Eventually, the researchers say, the both the liquid and hydrate CO2 dissolve into sediment pore fluids.

The researchers say cold temperatures and deeper injection are key.

‘Under a deep-sea setting, the high density and viscosity of CO2 result in a small footprint and, thus, high storage efficiency,’ the authors wrote in the study.

Carbon sequestration, or the process of capturing carbon from the atmosphere and storing it, is one of many methods scientists have turned to in hopes to keep global warming from getting out of hand. File photo

WHY ARE CLIMATE MODELS DIFFICULT TO PREDICT? The main problem with climate models is uncertainty. In particular, something called the 'equilibrium climate sensitivity' measure has been causing scientists a headache. This is a highly influential measure that describes how much the planet will warm if carbon dioxide doubles and the Earth's climate adjusts to the new state of the atmosphere. Studies have found a wide range of possibilities for this key measure — somewhere between 1.5 and 4.5°C, with 3°C. Most scientists try to constrain ECS by looking at historical warming events. For the last 25 years, the UN's Intergovernmental Panel on Climate Change (IPCC), the ultimate authority on climate science, has settled on a 'likely' range of 1.5°C to 4.5°C (2.7°F to 8.1°F). Warming less than 1°C is 'extremely unlikely' and more than 6°C is considered 'very unlikely', the panel has concluded. However, some scientists dispute this figure. Advertisement

‘This ensures great storage potential due to the wide distribution of deep-sea sediments globally.

‘Compared with terrestrial sequestration, less lateral expansion reduces the possibility of CO2 reaching a potential permeable pathway to the seafloor.

‘The generation of a hydrate cap and the possible negative buoyancy make this option free from reliance on the caprock in terrestrial storage. In our assumption, the unconsolidated marine sediment is intact.’

They’re now calling for real world tests to see how the method would perform outside of the simulations.