mozzaok wrote on Apr 15^th, 2010 at 11:23am:

You mean speculation:

The amount of methane being released from permafrost in the Siberian Arctic could rival that being vented from the entire world ocean, suggests new research. The study confirms what scientists have suspected for some time — that substantial quantities of the potent greenhouse gas are being released from sub-sea sites as the Arctic warms.

freediver wrote on Apr 13^th, 2010 at 7:22am:


Just in case anyone didn't get this, I will rephrase.

Higher temperatures can cause natural GHG emissions. GHG emissions (whether natural or unnatural) cause temperature increases. The truth of one does not invalidate the other. They are both true. Thus, the fact that in the past GHG concentrations lagged temperature does not mean anything by itself.

The sun causes the warmth. Greenhouse gases retain a portion of it in the atmosphere. We all know that. But you are suggesting that the percentage of retention is somehow hard wired in to the atmosphere, and is thus absolute. What nonsense! Obviously, the forcing rate can change, will change, and has changed as the composition of the atmosphere changes. To suggest that it can't is ridiculous, and there is defintively no evidence in support of it.

Soren wrote on Apr 15^th, 2010 at 11:12pm:


Your understanding is slightly flawed. In a nutshell (this is simplifying it quite a bit)

Greenhouse gases "reflect" radiation coming from the Earth and stop it from being lost into space (there is your primary cause). This causes the Earth's temperature to be higher than it would be without greenhouse gases. The name for this is the "greenhouse effect."

Most greenhouse gases are natural - water vapor is the most common, and causes most of the greenhouse effect on Earth. Other greenhouse gases in order of importance are carbon dioxide, methane, nitrous oxide and ozone. A natural greenhouse effect is not bad. Without greenhouse gases, the earth would be 15 to 30 degrees Celsius colder, and life would probably not be possible here.

It follows that if we add more Greenhouse gases, that retained heat increases even more and the average global temperature increases.

In a nutshell, we (the world's population) are adding too much more greenhouse gases to the atmosphere. This has caused the planet's average temperature to rise. The most important greenhouse gas that humans add to the atmosphere is carbon dioxide, of which there is much less then 1% in the atmosphere, but after water vapour, it's still the most important Greenhouse gas that we emit. We can quantify the warming effect very easily.

And as we've said before, increasing the CO2 will lead to additional heat capture, and increasing the temperature will increase global moisture content thus amplifying the warming effect.

Carbon dioxide is released when people burn fossil fuels, like oil, coal, and natural gas. It's also released when we breath, but the latter is an insignificant amount.

You could think of this analogy. On a cold day, you put on a teeshirt. You feel warmer. If you put on a jumper on top of that, it causes you to be even warmer - possibly too warm. Adding the jumper is a bit like like increasing the CO2 in the atmosphere..

So tell me something I don't understand Muso...  
Quote:


http://www.abc.net.au/catalyst/stories/2867591.htm

I don't have a problem...  alarmists do.

Don't be too hard on Muso Soren, he's working in a nutshell and trying to keep things simple so he's picked one Greenhouse Gas out of all the atmospheric gases, then decided that the small part of that that man produces is  to blame for global temperature rises even though it doesn't initiate the temperature change and doesn't rise in concentration till 800 years after the "unknown" temperature driver has been active.

At least that's what I think he's doing.