Vincent Fournier/The New York Times Pooled spring water that has bubbled up through Oman’s rocks reacts with CO2 in the air to produce an ice-like crust of carbonate.
How Oman’s rocks may save the planet
Scientists looking to harness reaction that cleans air of CO2
CLIMATE CHANGE
IBRA, Oman — In the arid vastness of this corner of the Arabian Peninsula, rocks form the backdrop practically every way you look.
But the stark outcrops and craggy ridges are more than just scenery. Some of these rocks are hard at work, naturally reacting with carbon dioxide from the atmosphere and turning it into stone.
Veins of white carbonate minerals run through slabs of dark rock like fat marbling a steak. Carbonate surrounds pebbles and cobbles. Even pooled spring water that has bubbled up through the rocks reacts with CO2 to produce an ice-like crust of carbonate.
Scientists say that if this natural process, called carbon mineralization, could be harnessed, accelerated and applied on a huge scale — admittedly some very big “ifs”
— it could help fight climate change. Rocks could remove some of the billions of tons of heat-trapping carbon dioxide that humans have pumped into the air since the beginning of the Industrial Age.
And by turning that CO2 into stone, the rocks in Oman — or in a number of other places around the world — would ensure that the gas stayed out of the atmosphere forever.
“Solid carbonate minerals aren’t going anyplace,” said Peter Kelemen, a geologist at Columbia University’s Lamont-Doherty Earth Observatory who has been studying the rocks here for more than two decades.
Capturing and storing carbon dioxide, the most prevalent greenhouse gas, is drawing increased interest.
The Intergovernmental Panel on Climate Change says that deploying such technology is essential to efforts to rein in global warming. But there are fewer than 20 large-scale projects in operation around the world, and they remove CO2 from the burning of fossil fuels at power plants or from other industrial processes and store it as gas underground.
What Kelemen and others have in mind is removing carbon dioxide that is already in the air, to halt or reverse the gradual increase in atmospheric CO2 concentration.
Direct-air capture, as it is known, is sometimes described as a form of geoengineering — deliberate manipulation of the climate.
Although many researchers dismiss direct-air capture as logistically or economically impractical, some say it may have to be considered if other efforts to counter global warming are ineffective.
A few researchers and companies have built machines that can pull CO2 out of the air, in relatively small quantities, but adapting and enhancing natural capture processes using rocks is less developed.
Kelemen is one of a handful of researchers around the world who are studying the idea. At a geothermal power plant in Iceland, an energy company is injecting modest amounts of carbon dioxide into volcanic rock, where it becomes mineralized.
Dutch researchers have suggested spreading a kind of crushed rock along coastlines to capture CO2. And scientists in Canada and South Africa are studying ways to use mine wastes, called tailings, to do the same thing.
If billions of tons of CO2 are to be turned to stone, there are few places in the world more suitable than Oman, a sultanate with a population of 4 million and an economy based on oil and, increasingly, tourism.
The carbon-capturing formations here consist largely of a rock called peridotite. The rocks are so extensive, Kelemen said, that if it was somehow possible to fully use them they could store hundreds of years of CO2 emissions.
IBRA, Oman — In the arid vastness of this corner of the Arabian Peninsula, rocks form the backdrop practically every way you look.
But the stark outcrops and craggy ridges are more than just scenery. Some of these rocks are hard at work, naturally reacting with carbon dioxide from the atmosphere and turning it into stone.
Veins of white carbonate minerals run through slabs of dark rock like fat marbling a steak. Carbonate surrounds pebbles and cobbles. Even pooled spring water that has bubbled up through the rocks reacts with CO2 to produce an ice-like crust of carbonate.
Scientists say that if this natural process, called carbon mineralization, could be harnessed, accelerated and applied on a huge scale — admittedly some very big “ifs”
— it could help fight climate change. Rocks could remove some of the billions of tons of heat-trapping carbon dioxide that humans have pumped into the air since the beginning of the Industrial Age.
And by turning that CO2 into stone, the rocks in Oman — or in a number of other places around the world — would ensure that the gas stayed out of the atmosphere forever.
“Solid carbonate minerals aren’t going anyplace,” said Peter Kelemen, a geologist at Columbia University’s Lamont-Doherty Earth Observatory who has been studying the rocks here for more than two decades.
Capturing and storing carbon dioxide, the most prevalent greenhouse gas, is drawing increased interest.
The Intergovernmental Panel on Climate Change says that deploying such technology is essential to efforts to rein in global warming. But there are fewer than 20 large-scale projects in operation around the world, and they remove CO2 from the burning of fossil fuels at power plants or from other industrial processes and store it as gas underground.
What Kelemen and others have in mind is removing carbon dioxide that is already in the air, to halt or reverse the gradual increase in atmospheric CO2 concentration.
Direct-air capture, as it is known, is sometimes described as a form of geoengineering — deliberate manipulation of the climate.
Although many researchers dismiss direct-air capture as logistically or economically impractical, some say it may have to be considered if other efforts to counter global warming are ineffective.
A few researchers and companies have built machines that can pull CO2 out of the air, in relatively small quantities, but adapting and enhancing natural capture processes using rocks is less developed.
Kelemen is one of a handful of researchers around the world who are studying the idea. At a geothermal power plant in Iceland, an energy company is injecting modest amounts of carbon dioxide into volcanic rock, where it becomes mineralized.
Dutch researchers have suggested spreading a kind of crushed rock along coastlines to capture CO2. And scientists in Canada and South Africa are studying ways to use mine wastes, called tailings, to do the same thing.
If billions of tons of CO2 are to be turned to stone, there are few places in the world more suitable than Oman, a sultanate with a population of 4 million and an economy based on oil and, increasingly, tourism.
The carbon-capturing formations here consist largely of a rock called peridotite. The rocks are so extensive, Kelemen said, that if it was somehow possible to fully use them they could store hundreds of years of CO2 emissions.