Burying CO2 'no silver bullet' for global warming

TRONDHEIM - Energy firms are stepping up projects to bury greenhouse gases but storage will not be a silver bullet to stop global warming, an International Energy Agency (IEA) expert said this week.

Capturing and pumping carbon dioxide underground at a cost of about US$35-US$55 ($57-$90) a tonne is too expensive to make sense for most industries, Kelly Thambimuthu, chairman of the IEA's greenhouse gas technologies research programme, said.

"It's expensive ... this can be one solution among many to global warming [but] it's not going to be a silver bullet," he said during a carbon dioxide conference in Trondheim, Norway.

Still, a handful of companies are getting involved in burying carbon, mostly in cases where it makes economic sense to filter and clean natural gas before sale from wells that naturally include high levels of carbon dioxide. Three existing schemes - by Statoil in Norway, EnCana in Canada and BP in Algeria - bury three million tonnes a year, he said.

Other planned energy schemes, by Chevron in Australia, Statoil and Royal Dutch Shell in Norway and by BP in Scotland and California would bury a further 12.5 million tonnes a year.

The figures are a pinprick in world emissions of greenhouse gases from human activities of more than 25 billion tonnes. A 500MW coal-fired power plant emits about three million tonnes a year.

Some experts say burying carbon dioxide could prove an easy way to offset global warming. And the gas can be pumped underground into a subsea oil reservoir, for instance, to keep up the pressure and force oil to the surface.

"If you look at the grand scheme of things ... [the planned carbon storage projects] are going to kick-start things, they're going to tell us a lot about carbon dioxide storage," Thambimuthu said. "But the real test in emissions reductions has to be in power generation and ... the transport sector. Those are the big hitters," he said.

Companies needing to buy permits to pollute on Europe's carbon trading market have to pay about €15 ($31) per tonne. Thambimuthu said this was not enough to encourage investment in storage.

"You need to have a threshold of at least about US$30 ($48) a tonne or higher."

He said Governments could cut carbon dioxide allocations to industries to push prices higher if they were serious about fighting climate change, or give tax breaks or other incentives.

Thambimuthu said burying carbon dioxide would raise electricity generation costs from coal-fired power plants by 50 per cent.

"At the same time the public demands cheap electricity," he said.

- REUTERS