A new Ice Age?

Question

My biology teacher told me today that when he was at a convention his step brother was giving a speach about a new ice age. During it he mentioned the tons of iron coming from Norway to the U.S, and concluded by saying ,"Give me an Iron barge bound for the U.S and I'll make a new ice age."
My teacher tried to explain before the bell and said that if an iron barge sunk at the right place in the North Atlantic it could trigger a new ice age. To me it seems insanly farfetched so is it true? If it is can you explain how?

Answer 1

That is actually a famous quote. The oceanographer John Martin first said it.

John Martin studied the relationship between various oceanic nutrients and phytoplankton growth. It was found that iron is one of the major nutrient limits. There have been experiments conducted where iron has been purposefully released into the ocean... all experiments resulted in massive growth of algae which then proceeded to suck all the rest of the nutrients out of the ocean and air.

What does this have to do with the ice age, you ask? Phytoplankton is one of the major players in the oxygen cycle (if not the biggest). If, for some reason, phytoplankton amounts were to increase, we'd see a global increase in oxygen in the atmosphere, and a corresponding decrease in carbon dioxide. Without carbon dioxide, much of the heat the Earth retains would be radiated back into space, and global temperatures would drop precipitously.

So your biology teacher may have been right. Of course, we don't really know if one shipload of iron would be enough by itself to cause an ice age, but the possibility certainly exists. Let's hope that we never find out!

Answer 2

There is an enormous "river" at the bottom of the ocean that circles the world known as the great ocean conveyor belt. Its formed as warm water flows north into the polar regions and sinks as it cools. The water then flows south to be warmed. If the conveyor is turned off, the major south to north currents, e.g., the Gulf Stream, will stop flowing and the regions at higher latitudes that depend on it for warmth will become frozen. I assume your teacher's barge or ship's sinking will somehow turn the conveyor off. How? You'll have to ask him.

Answer 3

Fermie probably had it right. Usually they talk about iron seeding of the antartic ocean where iron is lowest due to lack of dust blowing from land masses. I think it is pretty silly to think only a barge of iron would have much of an effect even if it was powderized and spread on the antartic ocean.

Answer 4

I, like jim z, am kind of skeptical of this notion. I mean, if it were true and scientists are so scared of global carbon dioxide levels, why don't they just drop a bunch of buckets of iron fillings into the ocean and see what happens?

This sounds like a job for Mythbusters... time to submerge an iron barge! If an ice age happens, oops. :-)

Answer 5

Sounds like your teacher should try out for an episode of The Twilight Zone.

Answer 6

may be
but no idea

Answer 7

He is lying.