Climate Aids in Study Face Big Obstacles

http://www.nytimes.com/2014/01/17/science/earth/climate-aids-in-study-face-big-obstacles.html

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Some of the technologies cited in the latest draft report by United Nations climate experts face significant obstacles before they can be widely put in effect to limit the impact of climate change.

The technologies, including a method of energy production that permanently removes carbon dioxide from the air, are still in their infancy, with few projects operating around the world.

The report from the Intergovernmental Panel on Climate Change refers to bioenergy with carbon capture and storage, or Beccs, as a possible mitigation technology. Beccs involves using biomass — often waste from crop or forest production — to produce energy.

Vegetation removes carbon dioxide that is currently in the air through photosynthesis and stores the carbon in its tissues. When the vegetation is burned, carbon dioxide is released. With Beccs, this gas is captured and injected deep underground. The net effect is permanent removal of carbon dioxide from the atmosphere.

Fossil fuels form from vegetation that is millions of years old, so capturing the carbon released by burning does not reduce current atmospheric concentrations.

Some studies have suggested that the technology, if widely adopted, could result in the removal of about 10 billion metric tons of carbon dioxide a year by 2050. (Energy producers and industry currently emit about 30 billion metric tons of carbon dioxide a year.)

But there are many challenges to widespread adoption of Beccs, and while there have been a few small demonstration projects overseas, there is only one in the United States, in central Illinois.

Financed by a $99 million grant from the federal Department of Energy in 2009, the project is storing carbon dioxide, captured from a nearby plant that produces ethanol from corn, in a formation 7,000 feet underground. In 2012 it stored 317,000 metric tons of carbon dioxide; the goal is one million tons a year until the project ends in 2016.

A 2012 report by the Global Climate and Energy Project at Stanford University noted some of the economic obstacles that Beccs faces. For one thing, the report said, emissions-trading plans do not recognize so-called negative emissions, so there are few financial incentives to develop such projects. And scaling up to the point where Beccs could have a meaningful impact on carbon dioxide levels would require an enormous financial investment.

There are technical hurdles as well. Existing power plants that burn biomass without capturing the carbon are far less efficient than coal-burning plants; adding carbon-capture technology reduces efficiency even further.

Questions have also been raised about the long-term effectiveness and safety of underground carbon storage. A 2012 study by two Stanford researchers suggested that, as with wastewater from oil and gas production, pumping carbon dioxide into rock formations could induce earthquakes. Though it is unlikely the quakes would cause significant damage on the surface, they might create pathways for the carbon dioxide to escape back into the atmosphere, the study suggested.