The Promise and Limitations of Carbon Capture
Advances in a new technique known as carbon capture will be critical as carbon-based energy supplies continue to be used around the world.
Published June 1, 2003
By Chris Michaud
Academy Contributor

How long can earth’s carbon-based energy supplies be sustained in the face of rising global demand? Can the environmental challenges that such energy sources pose be effectively mitigated?
To address these questions, Columbia University Professor Klaus S. Lackner told an April 17, 2003, Environmental Sciences Section gathering at The New York Academy of Sciences (the Academy) it is necessary “to destroy some preconceived notions.”
“Our problem is not that we are running out of energy,” Lackner told the audience. Rather, he posited that the problem lies in finding environmentally acceptable means of utilizing existing carbon resources to meet the world’s rising energy requirements. “Whether we like it or not,” he said, “we will have to look at carbon as a resource, see whether we have enough of it, and use that for the foreseeable future – in an environmentally acceptable manner.”
Now the Ewing-Worzel Professor of Geophysics at Columbia’s Earth Institute, Lackner’s opinion is based on 18 years of research at the Los Alamos National Laboratory, in New Mexico, where he worked on finding environmentally acceptable technologies for the use of fossil fuels. Fossil fuels provide 85 percent of all energy used in the world today. Contrary to common popular belief, Lackner said carbon-based resources continue to be both plentiful and relatively inexpensive.
Noting that the level of atmospheric carbon dioxide has risen from about 315 parts per million in 1958 to about 370 parts per million today, Lackner said the dilemma lies in the fact that “fossil carbon has caused environmental problems that need to be fixed,” adding that “we really cannot go on like that indefinitely.”
Demand for New Energy Innovations
Nevertheless, he noted that the continuing global desire for economic growth and development demands new energy innovations. Displaying a series of detailed charts and graphs showing historical energy consumption and GDP (gross domestic product) projections for the coming decades, Lackner said, “we are clearly creating an enormous shortage” by removing fossil carbon energy sources from the energy picture.
Due to increasing evidence of global climate change, Lackner said many people now believe the world must reduce its reliance on carbon energy sources. Adding credence to this argument is the “common wisdom,” which holds that “these are finite resources and we are bound to run out – it’s just a question of time.” Although “strong arguments have been made that we might run out of oil,” Lackner said, “that is not the same as running out of carbon,” and noted that coal reserves are plentiful.
The ultimate answer, Lackner said, lies in capturing carbon dioxide and utilizing the carbon resource without allowing excess carbon to escape into the atmosphere where it stays for about 100 years, possibly driving climate change.
The current challenge, he added, is “the technology issue of capturing carbon dioxide and putting it away, if for no other reason than there’s a huge resource sitting out there, and even if we try to be good about it and not use it, the temptation will be there until the day when we find another energy option that is even cheaper.”
Solutions

Using the world’s oceans for carbon deposits is not feasible, Lackner added, because carbon dioxide, an acid, changes the oceans’ pH level. And energy conservation, while laudable and helpful, is not going to solve the energy problem alone. In addition, it is difficult and expensive to collect carbon dioxide emitted by mobile sources, such as cars and airplanes, which generate a significant proportion of it. “We have a gap,” Lackner said, and new ideas and technologies are needed soon – within the next two decades.
Lackner proposed a couple of solutions: one is an artificial tree, a giant carbon-capturing device that he amusingly described as looking like a goal post covered with Venetian blinds; the other one is designed as a huge cooling tower. While the designs are still in an “early exploratory stage,” with various versions looking vastly different from each other, he said they all essentially aim to collect carbon dioxide directly from the air using wind as the transport agent.
Capture from air is rarely considered a viable option because carbon dioxide in the air is very dilute, a seemingly huge obstacle, but Lackner believes the technologies capable of capturing more dilute substances can be developed. He hopes for a pilot demonstration of one of the devices, which could lead to its commercial manufacture and implementation.
A Radical Alternative
Carbon dioxide capture from the air would provide a radical alternative to currently debated options for mitigating climate change, Lackner said. He estimated that about 250,000 of the artificial trees would be needed to take care of all of the world’s carbon dioxide emissions. But time, he added, is of the essence. International accords such as the Kyoto Protocol are also key to the effort.
“We need to do it soon,” so that the carbon capturing devices could be put into use by about 2020. “The building blocks are all working now,” he said. “But we are under severe time pressure. There is enormous demand for growth in developing countries. And we are kidding ourselves if we think we can get carbon dioxide emissions to go down over the next 20 years…Sometime around 2050 we will hit a brick wall, effectively having doubled the CO2 in the atmosphere…People will be aware of that by 2020,” he predicted.
Also read: How One Mozambican Researcher Hopes to Mitigate the Climate Crisis through Coffee