Ocean Iron Fertilization - Doing the Math

I wanted to revisit the Ocean Iron Fertilization idea I mentioned in my last blog post, to run the numbers and see if it's worth the controversy. I found out some interesting things.

I compared three approaches for reducing CO2: (1) OIF, (2) replacing 100 million incandescent bulbs with compact fluorescent or LED bulbs, and (3) replacing 1 million gas-guzzling cars with electric vehicles. The results are surprising. 1,000 tons of iron seeded into oceans beats both other options combined. And that's a small amount considering scientists are thinking about seeding 200,000 tons of iron into the oceans.

How do these compare to the size of the problem at hand. Consider that in 2030 the U.S. will emit 3.3 billion tons of CO2 into the air. So 40 million tons is barely over 1%. Now think that it would take 159,000 tons of iron to sequester 100% of the U.S.'s 2030 CO2 levels, and ocean iron fertilization begins to sound very intriguing, maybe even worth the risks.

Here are the rough calculations I did:

First off, 1,000 tons of iron seeded into algae blooms could sequester roughly 21 million tons of CO2.



Replacing 100 million light bulbs with more efficient compact fluorescent or LED bulbs could save 15 million tons of CO2.



A shocking finding for me was how little CO2 would be prevented by putting a million EVs on the road. Granted, part of this is because right now a big chunk of electricity comes from burning coal. If we moved more of our electricity generation to renewables, this number might increase. But right now a million EVs would remove less than 4 million tons of CO2, the same as 200 tons of iron fertilization.



On this rough evidence, OIF is definitely worth further investigation.

Forget Iron Man, How About Iron Algae?

The Ocean Iron Fertilization (OIF) Controversy

Algae, that wonder-plant that could be the biofuel of the future, could now also help solve the energy crunch problem from another angle: carbon sequestration. Simply put: there are many areas of ocean that have all the requisite elements for algae growth except iron. From time to time dust storms blow iron-rich soil into these oceans, just enough to satisfy the algae's 106:16:1:0.001 Carbon-Nitrogen-Phosphorous-Iron ratio, and huge algae blooms spring up (like the one pictured at right). This ratio means that for every atom of iron, 106,000 carbon atoms are bound into the algae. Or 83,000 pounds of CO2 for 1 pound of iron. The idea is that then 20-30% of the algae biomass sinks below the thermocline (100-200 meters) effectively sequestering the carbon from the atmosphere for hundreds of thousands of years.

I think the idea is a wonderful one in theory. But I would urge some caution when messing around with Mother Nature. A couple of anecdotes come to mind (although I'm sure you could find your own examples by throwing a rock in the air).

First is the story of saltcedar in New Mexico. In the early 20th century they brought in this non-native, deep-rooted species to solve the erosion problems they were having near the Pecos and Rio Grande rivers. The problem was that saltcedar was so successful, and so deep-rooted, that it spread like wildfire and began drinking the rivers dry. Now New Mexico spends millions of dollars a year in a near-futile effort to remove the plants and preserve water (if they're hard for nature to erode, then they're hard for us to remove).

Another story comes from my girlfriend's hometown of Medicine Lake, Montana. In the 30s and 40s they planted crested wheatgrass, a non-native prairie grass, in the Medicine Lake Wildlife Refuge thinking that it would provide a better shelter for wildlife. It proved too successful, growing so thick and so widespread that it's preventing wildlife from nesting there, opposite of the intended effect.

Maybe ocean iron fertilization would also prove too successful, pouring billions of tons of CO2 into the oceans and poisoning fish, replacing one set of problems with another.

In the next post I'll do the math to see whether it's worth exploring.

TerraPass - Consumer Driven Change

A few years back my friend Tom Arnold founded a company called . The company has been getting a ton of press and momentum, and for good reason. I love what they do and the concept is simple. You want to be carbon neutral, so you decide to offset the CO2 you put into the air by driving, flying, or heating your home. You go to TerraPass.com, input your driving/flying/home energy habits, and buy a corresponding TerraPass. They then put your money into clean energy projects, such as wind energy, that replace enough "dirty" energy to offset what you've pumped into the air, functioning like your own personal carbon offset. Great idea.

I just offset two business flights, a weekend flight for me and my girlfriend, and my flight home for Christmas, all for just $37. Then I offset my car for a year for $30 (I know, no electric car yet, can you believe it?). Conscience clear, but even more important, CO2 clear.

They've also announced great partnerships to effect change at the point of purchase, such as the ones with Enterprise, Alamo, and National. When you rent a car through these companies you'll be given the chance to offset the CO2 from your rental. Or with Expedia, which allows customers the same option when they book a trip.

I'd love to see even more of this, such as a GreenGrocer TerraPass at grocery store checkout lanes, giving you the ability to offset CO2 involved with the manufacturing and transport of your groceries. I'm sure Whole Foods customers would jump all over that, and it'd be a great marketing move for Whole Foods. Alternatively, other grocery chains could move first to capture more of that lucrative customer segment.

And my personal favorite would be if they could put an option right at the gas pump. Pay an extra 5 or 10 cents per gallon, and your entire fill-up is carbon neutral. I'd do that. But I wonder if Exxon and co. would go for that... "hey, pay a little extra to help put us out of business!" Hmmm, somehow I think it's a tough sell to the execs. But BP just might go for it, since they're trying to position themselves as the environmentally friendly oil company.