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HOME > PAST ISSUE > May-June 2011 > Article Detail

FEATURE ARTICLE

Global Energy: The Latest Infatuations

In energy matters, what goes around, comes around—but perhaps should go away

Vaclav Smil

Technical Fixes to the Rescue?

2011-05SmilF6.jpgClick to Enlarge ImageNew energy conversions are thus highly unlikely to reduce CO2 emissions fast enough to prevent the rise of atmospheric concentrations above 450 parts per million (ppm). (They were nearly 390 ppm by the end of 2010). This realization has led to enthusiastic exploration of many possibilities available for carbon capture and sequestration—and to claims that would guarantee, even if they were only half true, futures free of any carbon worries. For example, a soil scientist claims that by 2100 biochar sequestration (essentially converting the world’s crop residues, mainly cereal straws, into charcoal incorporated into soils) could store more carbon than the world emits from the combustion of all fossil fuels.

Most of these suggestions have been in the realm of theoretical musings: Notable examples include hiding CO2 within and below the basalt layers of India’s Deccan (no matter that those rocks are already much weathered and fractured), or in permeable undersea basalts of the Juan de Fuca tectonic plate off Seattle (but first we would have to pipe the emissions from Pennsylvania, Ohio and Tennessee coal-fired power plants to the Pacific Northwest)—or using exposed peridotites in the Omani desert to absorb CO2 by accelerated carbonization (just imagine all those CO2-laden megatankers from China and Europe converging on Oman with their refrigerated cargo).

2011-05SmilF7.jpgClick to Enlarge ImageOne of these unorthodox ideas has been actually tried on a small scale. During the (so far) largest experiment with iron enrichment of the surface ocean (intended to stimulate phytoplankton growth and sequester carbon in the cells sinking to the abyss) an Indo-German expedition fertilized of 300 square kilometers of the southwestern Atlantic in March and April 2009—but the resulting phytoplankton bloom was devoured by amphipods (tiny shrimp-like zooplankton). That is why the best chances for CCS are in a combination of well-established engineering practices: Scrubbing CO2 with aqueous amine has been done commercially since the 1930s, piping the gas and using it in enhanced oil recovery is done routinely in many U.S. oilfields, and a pipeline construction effort matching the extension of U.S. natural gas pipelines during the 1960s or 1970s could put in place plenty of links between large stationary CO2 sources and the best sedimentary formations used to sequester the gas.

But the scale of the effort needed for any substantial reduction of emissions, its safety considerations, public acceptance of permanent underground storage that might leak a gas toxic in high concentrations, and capital and operation costs of the continuous removal and burial of billions of tonnes of compressed gas combine to guarantee very slow progress. In order to explain the extent of the requisite effort I have been using a revealing comparison. Let us assume that we commit initially to sequestering just 20 percent of all CO2 emitted from fossil fuel combustion in 2010, or about a third of all releases from large stationary sources. After compressing the gas to a density similar to that of crude oil (800 kilograms per cubic meter) it would occupy about 8 billion cubic meters—meanwhile, global crude oil extraction in 2010 amounted to about 4 billion tonnes or (with average density of 850 kilograms per cubic meter) roughly 4.7 billion cubic meters.

2011-05SmilF8.jpgClick to Enlarge ImageThis means that in order to sequester just a fifth of current CO2 emissions we would have to create an entirely new worldwide absorption-gathering-compression-transportation- storage industry whose annual throughput would have to be about 70 percent larger than the annual volume now handled by the global crude oil industry whose immense infrastructure of wells, pipelines, compressor stations and storages took generations to build. Technically possible—but not within a timeframe that would prevent CO2 from rising above 450 ppm. And remember not only that this would contain just 20 percent of today’s CO2 emissions but also this crucial difference: The oil industry has invested in its enormous infrastructure in order to make a profit, to sell its product on an energy-hungry market (at around $100 per barrel and 7.2 barrels per tonne that comes to about $700 per tonne)—but (one way or another) the taxpayers of rich countries would have to pay for huge capital costs and significant operating burdens of any massive CCS.

And if CCS will not scale up fast enough or it will be too expensive we are now offered the ultimate counter-weapon by resorting to geoengineering schemes. One would assume that a favorite intervention—a deliberate and prolonged (decades? centuries?) dispensation of millions of tonnes of sulfur gases into the upper atmosphere in order to create temperature-reducing aerosols—would raise many concerns at any time, but I would add just one obvious question: How would the Muslim radicals view the fleets of American stratotankers constantly spraying sulfuric droplets on their lands and on their mosques?

These are uncertain times, economically, politically and socially. The need for new departures seems obvious, but effective actions have failed to keep pace with the urgency of needed changes—particularly so in affluent democracies of North America, Europe and Japan as they contemplate their overdrawn accounts, faltering economies, aging populations and ebbing global influence. In this sense the search for new energy modalities is part of a much broader change whose outcome will determine the fortunes of the world’s leading economies and of the entire global civilization for generations to come. None of us can foresee the eventual contours of new energy arrangements—but could the world’s richest countries go wrong by striving for moderation of their energy use?

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