In natural cycles, why does warming cause big releases of CO2?

[XemaSab]

-Question from a friend of XemaSab.

[Viva_La_Revolution]

1. gases trapped in frozen tundra and ice

are released when it melts. I don't think that's the whole answer though. :shrug:

[jgraz]

2. For another contributor, look at San Diego tonight

Warmer weather means more fires. They not only release tons of CO2, but they reduce the carbon sink as well. Much of the Amazon is on fire as well.

[DeSwiss]

3. I'm no scientist.......

.....but this is what I've learned and read. The "natural cycles" of which you speak took thousands of years to complete. And large natural CO2 releases in our prehistoric past, have been attributed to meteors striking the earth and the resulting fires and smoke they caused, and also huge volcanic eruptions which rained not only fire, but its own compliment of gases and smoke, including CO2. Which was further exacerbated by long periods where the sun's heat couldn't penetrate to the surface (because of the filtering effect of the smoke) as well, which in turn caused a resulting ice age. And these have occurred a number of times over millennia. During those periods, the earth's surface wasn't the same as it is now. So the absorption rates for CO2 were different as well.

But the vegetation covering the earth's surface during these periods was unchecked. Because there was no human activity then, and so vegetative growth was everywhere. This biomass was buried into the tundra and under the icesheets of the polar regions and northern and southern hemispheres during those past ice ages. These areas we're talking about here then covered much of the top and bottom quadrants of the hemisphere. So we’re talking about a very large portion of the earth’s arable land mass during those times. But as the skies cleared and the earth warmed, the ice receded in these areas, and vast releases of a number of gases, including CO2 and methane occurred. As it is doing right now.

It should also be understood that the periodic "blips" of long and continued warmth or cold during the development human civilizations, aren't part of these natural cycles. A few decades of altered temperatures - up or down - don't constitute a period or cycle in that sense. Its one of the more difficult things for many people to grasp, particularly those with doubts about global warming’s effects, when trying to understand these issues. Geological time, which covers thousands of years, cannot be compared to anything we experience now. But what is happening now is that the process has been accelerated. And even if we stopped using fossil fuels tomorrow, the process of what has begun wouldn't be altered for quite some time.

So a natural cycle of the past, would have begun at some point and ended several thousand years later. That's why vast amounts of CO2 are released as well - it had uninterrupted time to do so. The connection isn't as clear when one is "right in the soup so to speak." It can only be discerned when standing back and looking at it over long periods of time, with the study of climate as evidenced in the geological record.

So when one adds human activity to this mix, with our own CO2 discharges into the atmosphere, what we've done is to "tip the scales" beyond the earth's natural cyclical ability to adjust to "normal" releases of these gases. And the feedback loop that is caused by our continued use of fossil fuels, raises the temperature further and then speeds up the process exponentially.

There may be someone with a better grasp on the issues than me who can verify what I've read on this matter. But that's the way its been explained to me. :)

[lvx35]

4. see this:

I asked a similar question, here is one interesting answer
http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=118112&mesg_id=118117
and this:
http://www.democraticunderground.com/discuss/duboard.php?az=show_mesg&forum=115&topic_id=118053&mesg_id=118053

[skids]

5. let me count the ways...

1) Reduced CO2 solubility in warmer oceans
2) Forest fires
3) Permafrost methane release
4) Ocean methane hydrate release

[greenman3610]

6. think of a cold, fizzy coke, then think of a warm flat one

cold water holds more CO2, warmer water holds less

[AlecBGreen]

7. ding ding ding

lots of great answers to this question, but I think this is the most important fact:

Cold water holds more CO2 than warm water.