Thread: Less CO2 in the Atmosphere during The Great Ice Age.

Why? During the Great Ice Age, remants of which are still with us, even though the planet overall has been warming over the last 10,000 years, why would there have been less Carbon Dioxide in the air?My way of thinking, there should have been more. More than we currently have in the Atmosphere. ( If I researched it properly, from Google Sites, The Great Ice Age, ), ( less CO2 ), . Same reference stated 2/3, two thirds, of the Planet Earth for 70 thousand years covered in ice. OK. No trees in Northern Hemisphere, to speak of that is, so no soaking up of CO2. No grasslands to speak of, so no soaking up of CO2. Where did the CO2 spend The Great Ice Age? westwind.

off the top of my head i'd say biomass and carbonates - the former from plants turning CO2 into organic carbon, which then gets either buried (e.g. peat) or eaten, the latter dissolving into the oceans where many organisms capture it to build their shells

The great switchovers are usually related to the coincidence of Milankovitch or other orbital or tilt type cycles and, in the very large snowball earth type events, tectonic plate movements.

The Himalayas rising due to the collision between the Indian plate and the Asian plate are the reason for one big CO2 loss event. The exposed rocks react with or absorb CO2, get weathered and washed down by rain and by snowmelt and the streams and rivers empty into the sea. Oceanic little thingies incorporate the carbon compounds, die and fall to the sea floor where they eventually merge into sediments and become rocks after thousands of years. And that carbon never sees the atmosphere again unless tectonic and volcanic processes combine to throw them back out again or clever primates find ways to dig it up and burn it.

This will happen again when Africa and Europe eventually collide. The Alps will become the new Himalayas. But that's going to take a while. Your atlas won't be out of date for a good many thousand years yet.

And remember, it doesn't take much cooling to get an ice age. The last big one was only 2 or 3 degrees C less than our temperature was in the mid 20th century.

psst
we're still in an ice age
this is just an interglacial period
enjoy it while you can
The ice will return, driving the great armies of the north countries before it

CO2 may be the atmospheric gas less capable of warming the atmosphere
but it might help, so gas up the suv honey, we got a planet to save, and please, don't forget to fart

why would there have been less Carbon Dioxide in the air(during the ice age)?

The short answer is solubility of CO2 in the colder oceans increases, thus taking up more of the atmosphere's; a similar mechanism is probably responsible for the lag of CO2 levels after astronomically driven temperature changes.

Originally Posted by Lynx_Fox

why would there have been less Carbon Dioxide in the air(during the ice age)?

The short answer is solubility of CO2 in the colder oceans increases, thus taking up more of the atmosphere's; a similar mechanism is probably responsible for the lag of CO2 levels after astronomically driven temperature changes.

added to the which is that with the glaciers capping the land, no ghg, etc (products of microbial decay including C02) were entering the atmosphere

And always remembering, you can't actually have a full-blown ice age if CO2 concentration is above about 180ppm.

The CO2 gets absorbed, sequestered or relocated out of the atmosphere first and then the ice sets in. (Though Milankovitch cycles can make it easier or harder for this to happen in the first place, they're not enough to break the system out of the snowball earth configuration when it's fully established. For that, only CO2 can do the job.)

Originally Posted by adelady

And always remembering, you can't actually have a full-blown ice age if CO2 concentration is above about 180ppm.

The CO2 gets absorbed, sequestered or relocated out of the atmosphere first and then the ice sets in. (Though Milankovitch cycles can make it easier or harder for this to happen in the first place, they're not enough to break the system out of the snowball earth configuration when it's fully established. For that, only CO2 can do the job.)

You know that snowball earth is a very controversal theory and I would rather guess that there didn't exist an earth which had been covered by snow to 100%.

Another thing I want to add is the geological carbon cycle, earth mantle could be relevant for this.

geological carbon cycle, earth mantle could be relevant for this.

I understood that it was exactly that. CO2 gets absorbed by exposed rocks, washed down and eventually finishes up in the ocean where it gets absorbed into the bodies of little and large creatures which die and fall to the ocean floor and become silts. Sooner or later, whether or not they've had time to get compressed into rock forms, they get transferred into the mantle by subduction and are only ever returned to the atmosphere by way of vulcanism.

As for snow on a snowball earth - there wouldn't be a lot of ' snow', that's just a name for (super)extensive glaciation and frozen sea surface. With so much ice it's a bit too cold for evaporation, so the water vapour available to form snow would be a bit harder to come by.

Originally Posted by adelady

geological carbon cycle, earth mantle could be relevant for this.

As for snow on a snowball earth - there wouldn't be a lot of ' snow', that's just a name for (super)extensive glaciation and frozen sea surface. With so much ice it's a bit too cold for evaporation, so the water vapour available to form snow would be a bit harder to come by.

ok, let me correct me I meant snow and ice

Originally Posted by adelady

And always remembering, you can't actually have a full-blown ice age if CO2 concentration is above about 180ppm. ...

why 180?

180 ppm?

That's the way it seems to work. Right now I don't have the reference - my hard drive's blown up so I'm using my husband's computer which doesn't have my handy dandy list of nifty videos. I'll try and find it later today and post it.

There's also a nice list of papers about the relationship between ice ages/ hot periods and less/more atmospheric CO2. Have to track that down as well.

Ho hum. (At least I can't complain about being bored for lack of things to do for the next little while.)

this is my 5th computer, so much we depend on these things for, and with each one I've lost parts of books i was writing, pictures, and countless links to sites of interest

every tool is a crutch which helps us but limits our motion

really excellent that we have better and better memory storage devices---------we live in an age of technological miracles