1. Ocean Iron Fertilization
Evaluating the Potential of a Geoengineering Strategy for Climate Change
Heather McKee
April 29, 2008

2. Iron in the Oceans Sources of naturally occurring iron
Volcanic coastal shelves
Dust in blown in from land
Upwellings
Role in ecosystems
Key nutrient that helps
plants take up nitrogen

3. “Give me a few oil tankers full of iron, and I’ll give you an ice age
– John Martin, WHOI Scientist

4. Iron = Ice Age?
Ocean sediment cores suggest correlation between increased dust in air, decreased carbon dioxide, and ice ages

5. Ocean Iron Fertilization
More dust deposited (iron) = more phytoplankton =
more carbon sequestration = cooler temperatures

6. Cashing in on Carbon Offsets
Climos taking over with $3.5 million in funding
Planktos bottom up after Galapagos proposal

8. Speeding Up the Biological Pump
Climos claims:
Iron fertilization will increase overall phytoplankton
The increase in phytoplankton will speed up eating, pooping, dying by everyone
All the eating, pooping, and dying will remove and store carbon long-term

9. OIF: Good Climate Change Mitigation Strategy?
Does iron fertilization increase plant blooms?
Do those plant blooms effectively sequester carbon?
Do potential side effects of iron fertilization outweigh the benefits?

10. Does Iron Fertilization Increase Phytoplankton Blooms?
12 iron-seeding experiments conducted worldwide
Southern Ocean shows significant increased phytoplankton growth in response to iron fertilization

11. Do Phytoplankton Blooms Effectively Sequester Carbon?
3 studies out of 12 reported any carbon sequestration
One ton iron = Only 1,000 tons carbon
Could sequester 1.4% of global carbon emissions
Long-term effectiveness unknown

12. Do Potential Side Effects of OIF Outweigh the Benefits?

13. What Side Effects Could We Predict?
Large die-offs of phytoplankton will likely create
anoxic or hypoxic conditions on the ocean floor
Iron sulfide complex
could increase
ocean acidity

14. What Effects Do We Know About?
Silicaceous diatoms increase at greatest rate
Hard shells sink; desirable for carbon storage
Increases in methyl bromide and isoprene related to blooms
Not so great for eating

15. Salps: Carbon Vacuums? Will eat silicaceous diatoms
Fecal pellets sink 1000 meters
One of the only creatures that can survive in hypoxic or even anoxic conditions

17. What Precautionary Principle?
“This is an incremental thing. If you start to see that it’s going wrong, then you can roll back. Taking the first step does not inevitably mean that you have to go the whole road.”
-Watson of Planktos

19. What’s Driving OIF Research?
Iron ore costs $69/ton (+shipping, staff, sulfate costs)
1 ton iron = 1,000 pounds carbon sequestered
Currently limited to voluntary offset market at $5/ton
Maximum profit of $4,931 per ton of iron dumped, nearly a 70x return on initial cost of materials