CAPTURING CARBON WILL BE MOST CRITICAL CHALLENGE OF CENTURY

by Stephen Leahy

(IPS) -- Putting climate-altering greenhouse gases back in the ground where they came from is an essential part of any global plan to avoid catastrophic climate change, scientists say.

Capturing carbon dioxide emissions from coal-fired power plants and pumping the global warming gas deep underground or under the sea "may well be the most critical challenge we face, at least for the next 100 years," writes Daniel Schrag, director of Harvard University's Center for the Environment, in the journal Science Friday.

Coal is, and will continue to be, a major source of the world's energy and emissions of carbon dioxide (CO2), writes Schrag in the report "Preparing to Capture Carbon."

"By the end of the century, coal could account for more than 80 percent" of all CO2 emissions -- double the present level -- he writes.

Coal produces nearly twice as many emissions as natural gas, but coal is cheaper, and vast quantities are available and in the right places. The enormous and growing energy needs of the United States, India and China are matched by their even larger reserves of coal. It seems inevitable that thousands of new coal-fired power plants will be built.

Schrag is just one of a host of scientists, politicians, business leaders and even environmental groups who want to lower the amounts of CO2 going into the atmosphere by capturing and storing it.

"We cannot stabilise the global climate without India and China reducing their future emissions," says Robert Watson, chief scientist and director of Sustainable Development at the World Bank.

The industrialized countries will have to work with India and China on carbon capture and storage technologies, Watson said at a press conference Thursday.

Mary Griffiths, senior policy analyst at the Pembina Institute, an environmental group in Calgary, Alberta, adds, however, that "Carbon capture and storage is not our first choice for reducing emissions."

Carbon capture and storage (CCS) doesn't even come in second or third. Caps on CO2 emissions, energy efficiency, renewable energy and conservation are better ways to tackle the problem, she said.

"Avoiding dangerous climate change is a major challenge and therefore we need to use all the tools that are available," Griffiths told IPS.

And one of those tools is the much-touted -- and much-maligned -- "clean" coal technology.

Capturing CO2 from coal plants requires special processing of the coal with chemicals or through a gasification process. Both processes require extra energy and boost costs by as much as 50 percent, according to Schrag. Then the CO2 has to be pressurized, transported and pumped into a deep underground location.

Studies show there is potentially enough underground storage capacity, but there is limited data on whether such sites would leak and by how much. Schrag estimates that millions and eventually as much as 10 billion tons of CO2 per year will need to stay where they are put for "the next few millennia."

One leak-proof storage option is injecting CO2 below the sea floor but that would be very expensive.

There are no commercial-scale CCS examples but there are a few test sites demonstrating that it is technically feasible. One such site is in Norway, where about one million tons of CO2 is pumped into saline aquifers a kilometre below the bed of the North Sea.

The world's largest existing project has pumped five million tons of CO2 over four years into an old oil field in Weyburn, Saskatchewan in Canada to help pump put out more oil. The CO2 comes from a North Dakota coal gasification plant 325 kilometres away. This is a 40-million-dollar research effort funded by Canada, Europe, Japan and the United States.

There are also safety issues. CO2 is heavier than air and a large gas cloud could be lethal, as happened in a natural catastrophe at Lake Nyos in Cameroon in 1986 that killed 1,700 people.

Aside from the many environmental impacts of the coal industry as a whole, the most controversial aspect of CCS for coal power is who is going to pay for the development and additional ongoing costs.

"Governments shouldn't be making major investments in CCS, companies should be doing it," Griffiths argued.

Governments should put CO2 emissions caps in place, and that would create a market for investing in CCS, she said.

At the moment there are no such emissions caps in North America. In Europe, caps are in place, but the price of CO2 is well below the per ton costs of CCS. That, plus uncertainty about future caps and liability regarding leaks, means companies are unlikely to make the long-term investments that are needed, notes Schrag.

FutureGen is the Bush administration's much promoted effort to build the first commercial-scale near-emission-free coal power technology. Announced in 2003, the billion-dollar, public-private project has yet to find a site to build the plant.

SaskPower, a government power utility in Canada, could beat FutureGen as the world's first near-emission-free coal power plant. The 300-megawatt plant -- more than enough to supply a city of 200,000 -- could begin construction as early as this year.

However, none of these projects are guaranteed to work. Indeed energy experts still think CO2-free coal plants, if feasible at all, are well into the future.

Coal will not become carbon-free for another one or two decades, Wulf Bernotat, chief executive of the major German utility E.ON, told Reuters this week. E.ON is involved in several CCS projects around the world, but Bernotat said there are additional energy and financial requirements, as well as technical and legal problems to be overcome.

Europe's coal plants are investing in efficiency improvements first. But those five and 10 percent improvements won't be enough to avoid catastrophic climate change. The U.S. needs to encourage and sponsor 10 to 20 full-scale CCS efforts so that there will be a number of documented and verifiable CCS options available, writes Schrag.

"The United States and the world need carbon sequestration -- not right now, but soon and at an enormous scale," he said.