Hope rises for 'carbon sinks'

Posted: 1 December 2008

Author: Mallika Nair

As of November 24, 2008, the CO2 concentration in the atmosphere is up to nearly 388 ppm, the highest it's been for at least 650,000 years, and the rate of increase is ever accelerating. Scientists believe that these devastating figures could signal that the earth's natural capacity to absorb billions of tons of CO2 each year is being lost.

Although in order to contain global warming, reducing greenhouse gas emissions is still essential, improving information about and technology for carbon capture and storage is likely to be an important part of the climate change solution. Scientists worldwide are working to increase their understanding of the materials and conditions with the best potential to store carbon, and are beginning experiments to test these carbon 'sinks'.

Carbon storage, Norway
Carbon storage, Norway
The Sleipner A project injects carbon dioxide into saltwater aquifers deep beneath the sea floor off the Norwegian coast. Photo © Statoil
Carbon sinks are places where carbon dioxide is absorbed and stored for an indefinite period of time, and can be naturally occurring or man-made. There are two main natural mechanisms for carbon capture: photosynthesis by plants and algae, and the absorption of carbon dioxide from the atmosphere by oceans.

We already know that the loss of forests is one of the largest contributors to climate change. Previous research on carbon absorption by oceans suggested that changing winds, currents and temperatures associated with global warming might decrease the carbon storage capacity of the oceans.

Southern Ocean still able to store carbon

However a recent study on the Southern Ocean, also known as the Antarctic Ocean, the world's largest carbon sink, showed heartening data that although the ocean had undergone some changes it had maintained its ability to capture and store carbon. According to one of the researchers of the report published this week in Nature Geoscience, Steven Rintoul of the Center for Australian Weather and Climate Research, "It's a positive thing. It's one thing it looks like we don't have to worry about as much as we thought".

So for now, it appears that the Southern Ocean's status as a massive natural carbon sink is still intact. Simultaneously, the importance of developing man-made carbon storage techniques is gaining international recognition for the role it could play to minimize climate change. Just last week, the United States Department of Energy awarded $67 million to The Big Sky Regional Carbon Sequestration Partnership to co-fund a test project to store more than 2 million tons of carbon dioxide underground in Wyoming.

The U.S. DOE is involved in funding seven large-scale carbon storage projects like this one, and is hoping to develop the technology of carbon sequestration so that it is a marketable industry and feasible way to reduce the country's greenhouse gas emissions. Carbon sequestration, the storage of carbon dioxide in a solid material, involves injecting compressed carbon dioxide into deep geological basins with the capability to store that CO2 gas indefinitely.

There are some downsides to carbon sequestration. The technology can be very costly, and if improperly applied it can also be potentially dangerous. Although great care should be taken to find appropriate site to inject the carbon, there is always some level of risk of the carbon leaking out. If this were to happen, the liquefied carbon could mix with and contaminate drinking water supplies making them toxic. Alternatively, carbon that makes its way out to the ocean's floor or earth's surface could upset the balance of the ecosystem there, killing off plant and animal life.

Wyoming Project

While these scenarios are sobering, the climate change situation is too urgent to ignore the great potential of carbon sequestration. In the Wyoming Project, carbon sequestering wells will be drilled, and liquefied CO2 will be injected about 11,000 feet underground into sandstone formations that contain a saline solution that does not currently contain CO2. This eight-year project is one of many promising experiments in the growing field of carbon storage technologies. Other recent advances in the field include a new software tool developed by MIT engineers to calculate how much CO2 a given basin can store, using factors like the basin's porosity, temperature and pressure. This tool could be very helpful in increasing the safety of future projects.

There is a lot of hope and promise in carbon storage technology. There is also a lot of work and research needed to make sure it is completely safe and reliable. The responsibility to develop and spread this technology falls to the world's industrialized countries; not only do they have the resources to do so, but they can be some of the world's largest emitters of greenhouse gases.

Data from a UN report last week revealed that between 2000 and 2006 there was actually an increase of 2.3 per cent in the collective greenhouse gas emissions of 40 industrialized nations that signed the Kyoto Protocol. Still, we appear to be at the dawning of a new age of environmental awareness. Using innovative solutions to both reduce emissions and store the carbon we do produce, in accord with careful maintenance of natural carbon 'sinks', we will make progress in stabilizing our earth's climate.

- Source: Planet2025 News Network