Carbon sequestration and the precautionary principle

From Gristmill, a few highlights from a guest essay from Peter Montague, executive director of the Environmental Research Foundation: In response to a relentless stream of bad news about global warming, a cluster of major industries has formed a loose partnership with big environmental groups, prestigious universities, philanthropic foundations, and the U.S. federal government -- all promoting a technical quick-fix for global warming called "carbon sequestration."

"Carbon sequestration" is a plan to capture and bury as much as 10 trillion metric tonnes of carbon dioxide deep in the ground, hoping it will stay there forever. (A ton is 2,000 pounds; a metric tonne is 2,200 pounds; ten trillion is 10,000,000,000,000.) Though the plan has not yet received any substantial publicity, it is very far along....

If we accept this estimate of the carbon reduction needed -- cutting 80% from current levels -- then the allowable leakage must be reduced accordingly:

• if 25% of remaining fossil carbon is sequestered, any leakage above 0.16% (about one-sixth of one percent) of the total per year could eventually result in runaway global warming;
• if 75% of remaining fossil carbon is sequestered, then leakage greater than 0.05% (one-twentieth of one percent) of the total per year could eventually produce runaway global warming.

Can humans bury several trillion tons of carbon dioxide in the ground with complete confidence that 0.05% of it will not leak out each year? Never leak out? The leakage could begin at any time in the far distant future because the danger would lie buried forever, waiting to escape, a perpetual threat...

Clearly, these "experts" have their minds made up. But many common-sense questions remain:

• Given that there are many good alternatives, why would humans accept even a "very, very small" risk of making their only home uninhabitable?
• Given that the stakes are exceptionally high, shouldn't we approach this with a little humility and ask, "What if the experts are wrong? What if they are fallible and haven't thought of everything? What if their understanding is imperfect?" After all, geology has never been a predictive science, and humans have no experience burying lethal hazards in the ground expecting them to remain there in perpetuity.
• Since everyone alive today -- and all their children and their children's children far into the future -- could be affected, shouldn't we have a vigorous international debate on the wisdom of carbon sequestration versus alternative ways of powering human economies? Don't we have an obligation to develop a broad international consensus before proceeding -- especially among the nations most likely to be harmed if carbon sequestration fails? [4, 5, 6, 7, 8].
• And finally, given the exceedingly high stakes, the irreversible nature of carbon sequestration, and the substantial and irreducible uncertainties involved, isn't this a decision that cries out for application of the precautionary principle?