EMERGING ISSUE: Potential CO2 leaks from carbon capture and storage projects, like this one at the Mountaineer coal-fired power plant in West Virginia, could simply postpone global warming, experts warn.
Image: David Biello
Seepage of carbon dioxide from long-term carbon capture and storage projects may lead to delayed global warming unless the gas can be tightly controlled, according to a new study.
Unless the seepage rate of sequestered carbon dioxide can be held to 1 percent every 1,000 years, overall temperature rise could still reach dangerous levels that cause sea level rise and ocean acidification, concludes the research published yesterday in Nature Geoscience.
The delayed warming resulting from escapes of gas would occur gradually for hundreds of years, but could be problematic and expensive for future generations who would have to figure out how to recapture the C02 from the atmosphere, said study author Gary Shaffer, a professor at the University of Copenhagen and the University of Concepción in Chile.
"It may be a useful thing to carry out this carbon sequestration, but there are dangers, and the best thing would be to decrease emissions in other ways that make it unnecessary," said Shaffer.
Carbon capture and sequestration, or CCS, has never been proved at scale. It envisions grabbing C02 from an industrial process or a power plant stack, piping the gas to a suitable storage spot and injecting it deep beneath the Earth's surface.
The technology is considered critical for the survival of coal in a carbon-constrained world, considering that the fossil fuel produces almost 50 percent of U.S. electricity and about a third of the nation's carbon dioxide emissions.
What if 1 percent leaked?
Billions of dollars are committed to research and deployment of CCS globally, but the commercial operation of equipment on all the nation's coal plants could be decades away. Engineers also are considering deploying the technology on other sources of emissions, such as natural gas plants.
Shaffer examined several leakage scenarios of roughly 3,000 gigatons of stored C02, which would take two centuries globally to accumulate after multiple underground injections. He then examined how the world's temperatures would fare if that amount of gas leaked at rates of 1 percent every 10, 100, and 1,000 years.
"The whole reason for doing this study is because C02 in the atmosphere has a very long lifetime," Shaffer said.
A leakage rate of 1 percent every decade could be "very serious," he said, and would eventually lead to temperature spikes of about 3 degrees Celsius in the next century and a rise close to 4 degrees Celsius over the following 2,000 years. Many scientists have argued that warming needs to stay within the range of 2 degrees Celsius above pre-industrial temperatures.
Stored gas leaking at 1 percent every 100 years would keep the temperature rise close to 2 degrees Celsius, Shaffer said. Storing gas underneath the ocean floor is a "poor choice," he said, since gas leaking at the same rate could spur acidification and harm corals and other sea life.
A 1 percent leak rate every 1,000 years would keep warming levels "manageable," Shaffer said. The study predicts, for example, that warming would hover below the 2 degrees Celsius threshold for the next 20,000 years at that rate.
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Reply | Report Abuse | Link to thisIf you have to collect it in order to sequester it, doesn't that mean you would already own the gear necessesary to also recapture and reinject future leaks?
Just feed it to the plants.
Reply | Report Abuse | Link to thisNo. At this time the CO2 is extracted from the power plant exhaust, not from the atmosphere. No economically feasible means has yet been found to extract CO2 from the atmosphere.
Reply | Report Abuse | Link to thisHydrocarbons can be pyrolysed to seperate the carbon and hydrogen. The hydrogen can then be safely burnt producing water, and the carbon stored in land-fill sites. This is cheap, as pyrolysis is an exothermic reaction, and carbon is inert. So oil and gas can provide energy, but coal has no future.
Reply | Report Abuse | Link to thisSee www.eprida.com for information on pyrolysis.
Forest carbon sequestration is best approach to store carbon from the atmosphere.
Reply | Report Abuse | Link to thisIs there any study done regarding Change in Carbon storing capacity of Forest in this changing climate(Business as usual scenario).
This article is based on the false premise that we have 200 yrs of fossil fuels left! Facts are we don't. While the US has probably 200 yrs worth at the rates we are using it, a good amount is not recoverable. The rest of the world has far less, about 40 yrs or so.
Reply | Report Abuse | Link to thisOil to burn is probably less that 30 yrs worth before it gets too expensive for that.
Next CO2 become liquid at pressures 1000' down or more so unlikely to come back up. But most will be put in NG, oil wells which holds NG at 3000psi+ so again unlikely to escape.
But all that is too expensive as RE is far cheaper. Here is another post on after the coal is gone,
First we will never run out of oil, coal or most anything else, it will just get too expensive to extract.
Facts are for most energy, solar PV/ CSP, wind and eff, conservation can serve most needs. Now add biomass, river/tidal kinetic, inherently safe, smaller nukes solves most of the rest.
But what a world will we have if we burn most of the oil, coal? Even assuming no GW, the oceans will be dead from CO2 acidification and pollutions from them will make life not very good.
What we need to do now is put the full cost of oil, coal in them and the above RE which are about competitive now will be the cost effective choices.
It only takes $500 to build a 2kw windgen that puts out about 15-20kwhrs/day in many places that can supply a family both home and transport energy if well designed, not really anymore costly, in fact cheaper than fossil fuels even now. And lasts 50+ yrs.
PV panels are now $2k/kw retail if shopped well which is cost effective with coal.
Solar CSP is just a 5hp steam engine with 200sq' of a trough collector that provides 15-25kwhrs/day of electric and 45-75kwhrs of heat. It can be built for under $5k retail in mass production.
I drive my EV's every day that get 250 and 600mpg equivalent. They can be built for under $10k and $6k. They use no more material, labor than NEV's now built for that.
There is no shortage of energy, it's a political problem, not technical. We just need to get big coal, oil out of the way and stop subsidizing them and the rest will fall into place, hopefully before we kill our planet!