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It's reasonable to assume, if we have also already assumed that the correlation is true, and we have also exhausted alternate means to explain a correlation due to some mutual causal factor, that, over similarly ludicrously large periods of time, human increases in Co2 will produce an effect in temperature. It would not be reasonable to expect that the trend would respond quickly.

You're missing something though. Assuming that one of either CO2 or Temperature must be the causal factor in their mutual correlation, why do you assume it's CO2?

Temperature changes precede CO2 change in the ice core readings we have. Every single time. Effect cannot precede cause. Therefore, if one of the two is the causal factor (and not some third factor), then it must be temperature, not CO2.

It's absolutely false to assume that this historical correlation between CO2 and temperature at all supports the idea that increasing CO2 rates will increase temperature. Surely you can see this.

Does temperature rise cause CO2 rise or the other way around? A common misconception is that you can only have one or the other. In actuality, the answer is both.

Milankovitch cycles - how increased temperature causes CO2 rise

Looking over past climate change, scientists have observed a cycle of ice ages separated by brief warm periods called interglacials. This pattern is due to Milankovitch cycles - gradual, regular changes in the earth's orbit and axis. While there are several different cycles, the dominant climate signal is the 100,000 year eccentricity cycle as the Earth's orbit changes from a more circular to a more elliptical orbit (Petit 1999, Shackleton 2000).

The eccentricity cycle causes changes in insolation (incoming sunlight). When springtime insolation increases in the southern hemisphere, this coincides with rising temperatures in the south, retreating Antarctic sea ice and melting glaciers in the southern hemisphere (Shemesh 2002). As temperature rises, CO2 also rises but lags the warming by 800 to 1000 years (Monnin 2001, Caillon 2003, Stott 2007).

How does warming cause a rise in atmospheric CO2? As the oceans warm, the solubility of CO2 in water falls (Martin 2005). This causes the oceans to give up more CO2, emitting it into the atmosphere. The exact mechanism of how the deep ocean gives up its CO2 is not fully understood but believed to be related to vertical ocean mixing (Toggweiler 1999).

The greenhouse effect - how increased CO2 causes temperature rise

When there's more CO2 in the atmosphere, the earth absorbs more heat. Shortwave radiation from the sun passes straight through our atmosphere and is absorbed by the earth. The earth reemits it as longwave (infrared) radiation which is partially absorbed by atmospheric CO2. This is the greenhouse effect. CO2 lets energy in, doesn't let as much get out.

CO2 warming explains how the relatively weak forcing from Milankovitch cycles can bring the planet out of an ice age. It begins with the high southern latitudes (eg - Antarctica) warming and releasing CO2 from the oceans. The CO2 mixes through the atmosphere, amplifying and spreading the warming to northern latitudes (Cuffey 2001). This is why warming in the southern hemisphere precedes warming in the northern hemisphere (Caillon 2003). This is confirmed by marine cores that show tropical temperatures lag southern warming by ~1000 years (Stott 2007).

Climate sensitivity - how CO2 amplifies temperature increase

Climate sensitivity is defined as how much global temperature increase if we doubled CO2. Studies of past CO2 and temperature records have helped quantify how sensitive our climate is to changes in CO2.

Temperature and various forcings (including CO2) over the past few centuries shows a climate sensitivity between 1.5 to 6.2°C (Hegerl 2006). One study combines the results from various paleontological studies to narrow climate sensitivity to around 2.5 to 3.5°C (Annan 2006). Basically, multiple studies covering many different periods of earth's history confirm that when CO2 is doubled, global temperatures go up around 3°C.

So what does the CO2 lag tell us? The behaviour of CO2 in the past confirms the amplifying effect of CO2 in the atmosphere. Sharp temperature rises in the past indicate how sensitive climate is to change. Our past history shows how our climate is prone to "tipping points" where warming can lead to positive feedbacks sparking a warming effect.

As for CO2 causing warming - it is a greenhouse gas. No one seriously debates that.

We have one forum poster who seems to indicate that it isn't - who literally said we will asphyxiate on CO2 before it raises temperature.

The real place climate skeptics can attack is the significance of the CO2 amounts which we put into the atmosphere - but at this point you've gone to computer simulations. It is one of many competing factors, all of which need to be accounted for.

Vastly? According to who? Were you going to provide numbers or cites? Is this like you saying "absolutely" and I should take it to mean "Not at all because I have no idea what I'm talking about"?

Right. "Fall back on". Gotcha.

According to who? You?

Hehehehe... Ah, you.

The points I was responding to don't require links to prove them anymore than me saying "No. 5 is greater than 1" requires a link.


It's irrelevant anyway. We all know what your response will be to any link I do post. You've defined "legitimate climate scientist" as those who agree with the global warming hype, which provides you a convenient label and dismissal of anyone who disagrees, no matter what fields they are in, how many of them they are, how much experience they have, how respected they were before this thing became a political animal, and ultimately how much more sense they're making than the guys at the IPCC.

Ah, Me? What does that mean exactly? I'm right, but you don't want to acknowledge it?

Just one of a zillion sites out there discussing the problems with Global Warming

And while I'm at it: Here's one discussing the whole CO2/Temperature relationship

Please tell me that this isn't a reference to me. I didn't say that at all. I was responding to someone who said that it wasn't just about temperature, but CO2. My response was that the only reason we worry about CO2 is because it may cause the temperature to rise via a greenhouse gas effect.

Actually, what I was hinting at there is that really high concentrations of CO2 will cause asphyxia in humans. Not because the gas is poisonous, but because we can't actually breathe it. Too much CO2 means there's too little O2 and Nitrogen, which is what we need. CO2 is bad for us in more or less the same way that water is. We can't breathe it. That's really it.

Link

But they won't allow Christmas Trees.

And anyone else notice that it always seem to take 5+ of you to argue against Gbaji.

Edited, Dec 6th 2009 8:35pm by ThiefX

And anyone else notice that it always seem to take 5+ of you to argue against Gbaji.

And anyone else notice that it always seem to take 5+ of you to argue against Gbaji.