Iceland has long been a pioneer in the battle against global warming, tapping its unique combination of volcanoes, geysers and thundering waterfalls to produce all the electricity, heat and hot water it needs while protecting the environment.
But this remote island nation is now planning to test another natural resource — its basalt rocks — to see if they can be used to safely bury carbon dioxide gas emissions before they harm the atmosphere. And if the experiment works, it also could prove useful in much bigger countries that also have basalt, such as the United States, India, Brazil and Russia.
"Action on global warming cannot be delayed," said Wallace Broecker, a professor at Columbia University who is joining Iceland scientists in the study.
"The availability of cheap coal and the desire by developing countries for more energy virtually guarantees that, despite our best efforts, CO2 production will continue to rise. If we are to succeed in capping the rise, we will need to supplement conservation and renewables with CO2 capture and burial," Broecker said.
Scientists around the world have known for more than 50 years that the natural chemical weathering of rocks consumes some atmospheric C02.
In countries such as Iceland, rain pulls a small amount of C02 out of air. When the rain hits rocks, the chemical weathering begins, dissolving solids such as calcium. The water reacting with the rocks then absorbs even more C02 from the atmosphere.
Rivers that capture this water carry the dissolved C02, plus chemical constituents from the weathering process, to the ocean. There, the calcium and dissolved C02 combine and form solid calcium carbonate, similar to the material in sea shells, and it sinks to the bottom.
Using chemical reactions
This is a natural process that has been under way for millions of years. But the chemical weathering of basalt, the natural rock of Iceland, is fast compared to other rock types and it contains a lot of calcium, which can combine with C02 to form calcium carbonate.
That is one reason the experiment by U.S. and local scientists is being planned in Iceland. Another is that this country has the scientific environment and the experience needed to bury captured C02 deep beneath the land's surface and see what happens to it.
Icelandic, U.S. and French scientists have been studying chemical weathering and water rock interactions in nature and in laboratories for decades. The use of geothermal energy also has made Icelanders skillful in drilling and understanding chemical reactions among gases, water and rocks in their country's geothermal systems.
"We hope to show the world in this pilot study that a natural process can be used to transform CO2 emissions into a solid state and to safely store them underground for thousands, if not millions, of years," said Sigurdur Reynir Gislason, a research professor of geology at the University of Iceland in Reykjavik, who is involved in the project.
"We also believe this process could not only be possible in Iceland but in other countries that also have basaltic rocks," he said in an interview in his office.
The Earth Institute at Columbia University is raising the $4-5 million needed for the pilot project. Scientists, Iceland's government and local power companies hope to finalize the plan in June and to launch the experiment next year, Broecker said.
Eileen Claussen, president of the Pew Center on Global Climate Change in Washington, said she is encouraged by such projects.
"The Pew Center, along with many others, believe that carbon capture and storage underground in geological formations can be a significant part of the solution to climate change," she said in an interview. "Investment in these technologies illustrates the magnitude of the challenge and the lengths people are willing to go in order to change the dangerous path we're on," said Claussen, who has no connection with the Iceland experiment.
Other capture projects
The Iceland project wouldn't be the only one involving the disposal of C02.
For 10 years, Statoil, a Norwegian oil and gas company, has been separating C02 contained in natural gas that it takes from beneath the North Sea. The C02 is then liquefied and pumped into a well that was dug into sandstone 3,300 feet below the sea bed for that purpose.
Four companies — BP, Conoco Phillips, Shell, and Scottish and Southern Energy — are developing a project off Scotland where they would take North Sea natural gas, convert it into C02 and hydrogen gas. The hydrogen would be burned in a power station to generate electricity. The C02 would be pumped through an existing gas pipeline to an aging oil field in the North Sea, where it would be permanently stored.
But the experiment in Iceland could prove it is possible for many countries to safely deposit captured C02 in their natural resources, not just in empty oil wells.
One option in the Iceland experiment would be to import C02 from Statoil in a liquid form and pump it down deep into the basaltic rocks. The chemical weathering would occur in the rock, calcium would be extracted from the basalt, combine with the C02 and form solid calcium carbonate. Then it would be monitored to see if it remains safely stored with no time limit.
If the experiment works, countries such as Iceland, the United States, India, Russia and Brazil could theoretically be able to capture C02 before it is released from factories, industries and coal mines and bury it out of harm's way.
"Iceland won't save the world, even if this process works," said Sigurdur.
"No one has the capacity to capture all the C02 that is being burned in fossil fuel. But more and more evidence suggests the climate is warming up. We have to do something," he said.
That also is true in Iceland, where Europe's biggest glacier, Vatnajokull, still covers about 10 percent of the country.
Icelanders have been harnessing the energy in the water rushing from the glaciers and mountainsides for nearly 100 years and turning it into all the electricity they need. This is called hydropower, a renewable energy supply that emits no greenhouse gases.
Geothermal energy — produced from hot water and steam captured from beneath Iceland's surface — provides clean, safe and pollution-free hot water and inexpensive space heating to more than 90 percent of Icelandic homes, as well as its swimming pools and greenhouses.
But like many other countries, Iceland still imports the fossil fuels that its cars, trucks, large fishing fleet, airplanes and some industries need, meaning it's difficult to meet the emission targets the nation agreed to under the Kyoto Protocol.