The New Iron Age
In our first radio show, Phil brought up an idea for combating the greenhouse gas CO2 that I hadn't heard before - seeding the oceans with iron. The August edition of Popular Science details several different methods for dealing with Global Warming, but the "iron-the-oceans" idea looks like the most promising. For the record, the other methods discussed are:
- Store CO2 Underground (which is already being done in small amounts).
- Filter CO2 From The Air.
- Turn CO2 To Limestone.
- Enhancing Cloud Cover.
- Deflect Sunlight With A Space Mirror.
According to the article, the average American puts 25 tons of CO2 into the atmosphere annually. One-half pound of iron strategically seeded in the right part of the ocean could encourage the growth of sufficient plankton to sequester the typical American's annual output.
At a lecture more than a decade ago, [oceanographer John Martin] declared: “Give me a half-tanker of iron, and I will give you an ice age.” He was alluding to the fact that the Southern Ocean is packed with minerals and nutrients but strangely devoid of sea life. Martin had concluded that the ocean was anemic—containing very little iron, an essential nutrient for plankton growth. Adding iron, Martin believed, would cool the planet by triggering blooms of CO2-consuming plankton.
This idea has now been tested.
On January 5, 2002, Revelle, a research vessel operated by the Scripps Institution of Oceanography, left New Zealand for the Southern Ocean—a belt of frigid, stormy seas that separates Antarctica from the rest of the world. There the scientists dumped almost 6,000 pounds of iron powder overboard and unleashed an armada of instruments to gauge the results.
The experiment proved that small amounts of iron can encourage the growth of huge plankton blooms.
Some scientists are concerned that cultivating plankton blooms in the South Seas could devour nutrients essential to life in other parts of the ocean. We'd have a nice cool planet with a dead ocean.
Probably every method that Popular Science discussed for reducing atmospheric CO2 has the potential for dangerous unintended consequences. Our planet is such a complicated system, that it may be impossible to know with 100% certainty all effects that any method for reducing CO2 could have.
To prevent unintented consequences on a massive scale, plankton cultivation should be incrementally implemented. If at any point the practice begins to cause a problem, the amount of plankton cultivated could be reduced. And, before beginning, I'm sure the scientific community would want to do extensive modeling with Japan's Earth Simulator.
Of all the solutions for global warming discussed in the article, only the "iron-the-ocean" solution harnesses life to do the work for us. All the other solutions would require the expenditure of massive amounts of energy - often by burning fossil fuels. But here, we would be using the energy of the sun (via photosynthesis) to cool the planet. This solution to global warming is simply too feasible to be ignored.
“Even if the process is only 1 percent efficient, you just sequestered half a ton of carbon for a dime.”