“I take it as a given that globally we’re going to be dealing with carbon management issues for a long time,” WHOI marine policy analyst Hauke Kite-Powell told participants at the WHOI conference. “And we will probably be dealing with them in the context of some combination of policies including carbon taxes, emission caps,” and other economic incentives.
Large-scale iron fertilization is unlikely to be commercially feasible unless nations start to charge carbon emitters and make room for iron fertilization in regulated markets. Otherwise, iron fertilization companies would be limited to volumes they can sell on the voluntary market, which according to Neeff traded 24 million tons of carbon dioxide equivalents (6.5 million tons of carbon) last year—less than 1 percent of the oceans’ projected sequestration potential. Even so, tens of millions of tons is equal to hundreds of millions of dollars, a strong incentive for some companies to move forward on ocean iron fertilization proposals.
Presenting an economic analysis of the value of iron fertilization over the coming century, Kite-Powell formalized the seesawing relationship between the cost of carbon emissions and the true costs of conducting iron fertilization, verifying its effects, and coping with its environmental side effects. Kite-Powell’s model projected that fertilizing one-fifth of the oceans’ high-nutrient, low-chlorophyll waters each year could generate a value of $100 billion in atmospheric carbon dioxide mitigation over the next century. But that’s only if ocean iron fertilization can be shown to be effective, without significant side effects, and amenable to monitoring and verification (“auditing” in carbon credit jargon) at reasonable cost.
By comparing a range of possible costs for iron fertilization with published projections of economically optimal future carbon prices, Kite-Powell arrived at an economic timetable for the iron fertilization industry and calculated its potential role in reducing net global additions of carbon dioxide to the atmosphere. When Kite-Powell entered a price on the low end of possible iron fertilization costs—$30 per ton of carbon sequestered (about $8 per ton of carbon dioxide)—his model suggested iron fertilization could be economically feasible by 2015 and could offset 100 million to 200 million tons of carbon per year—a few percent of global emissions of greenhouse gases.
But the difficulties associated with monitoring iron fertilization’s effectiveness and its side effects mean the actual cost per ton is probably much higher than $30, and this would push back the date when carbon emissions prices would make it profitable. With a cost of $60 per ton of carbon, for example, Kite-Powell’s model predicts iron fertilization wouldn’t be economically worthwhile until at least 2035. And by then, with an extra 20 years of emissions collected in the atmosphere, iron fertilization’s contribution to global emissions reductions would fall.
Despite the urgency of dealing with the carbon problem, Kite-Powell sees a benefit to postponing commercial implementation of iron fertilization, since the delay gives scientists time to work out the procedure’s many unknowns and regulators time to decide how to include ocean iron fertilization in carbon markets and international laws.
“It’s an understatement to say that the remaining uncertainties about all aspects of this are huge,” Kite-Powell said. “But the potential value of the option is also not insignificant, assuming that it works, and assuming that the side effects are minimal, and assuming that we can figure out how to do verification in an affordable way. To my way of thinking at least, this warrants additional work on the problem.”