While many countries have made pledges to reduce their carbon emissions over time, according to the United Nations Environmental Program (UNEP), at our current pace we will exceed 3℃ of global warming. This increase is much higher than the Paris Agreement’s goal of limiting warming to below 2℃ and striving for only 1.5℃. In order to avoid the worst of the consequences of climate change, the UNEP states that we must remove 10 billion tons of CO2 from the atmosphere by 2050.

We need to capture such a large amount of atmospheric carbon to slow global warming, we must also employ other methods in addition to natural ones. Fortunately, teams of scientists are inventing various methods to solve this problem. Let’s walk through two promising solutions that give us hope for the future and remind us of the importance of scientific research.

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Research in Oman

The Oman Drilling Project employs over 200 scientists to study a unique feature of the Oman desert: the oceanic crust of the earth and the underlying mantle rocks have been brought to the surface through tectonic plate movement. Some of the project’s scientists are investigating how this feature could help combat climate change.

Atmospheric carbon dioxide reacts with rocks from the earth’s mantle, forming “carbonate” materials. This process captures the carbon dioxide and stores it in a solid form.

A group of scientists working for the Oman Drilling Project have found that cooking limestone releases CO2 – which can be stored or used – and calcium oxide (CaO). Then, they put the CaO out in the weather and it absorbs more carbon dioxide, creating limestone. This relatively simple process is repeated over and over again. The scientists have found that they can convert 75% of CaO into limestone in less than two weeks, just by exposing the limestone to air in their lab. They claim that this is the lowest peer-reviewed cost estimate of any Direct Air capturing method.

Start-ups, such as Heirloom Carbon Technologies in California, are beginning to harness this method. They have committed to removing one billion tons of CO2 from the air by 2035. Another start-up in Oman called 4401.Earth plans to remove carbon from the air and store it below the surface as solid carbonate materials.

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Research in Japan

Scientists at the Institute for Integrated Cell-Material Sciences (iCeMS) at Kyoto University have been studying a method of carbon capture that turns CO2 into useful chemicals. The CO2 is converted into structures called metal-organic frameworks (MOFs), which can be used as biosensors and catalysts.

They start by bubbling CO2 at 25℃ at a pressure of 0.1MPa through a solution with an organic molecule called piperazine. The MOF emerges as white microcrystalline powder that is then dried and collected.

The team of scientists is investigating how to harness this reaction to convert CO2 from industrial fumes emitted from fossil fuel plants into MOFs. If successful, this conversion process has the potential to turn a greenhouse gas that contributes to climate change into a scientifically useful material.

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One Last Thing

All forms of carbon capture and storage – natural and human-made – are important in the fight against the climate crisis. We look forward to seeing what methods scientists come up with in future.