IPCC High-End Estimate Of Temperature Increase - 4.5C (8.1F) At 550 PPM - AFP

[hatrack]

Earth's surface temperature could rise by 4.5 C (8.1 F) if carbon dioxide levels double over pre-industrial levels, but higher warming cannot be ruled out, according to a draft report under debate by the UN's top climate experts here Tuesday. The draft -- being discussed line by line at the four-day meeting of the Intergovernmental Panel on Climate Change (IPCC) -- grimly states that the evidence for man-made influence on the climate system is now stronger than ever.

And carbon dioxide (CO2) pollution spewed out this century will stoke global warming and sea-level rise "for more than a millennium," given the time it takes for fossil-fuel pollution to degrade, it says. Among other things, the document declares it "very likely" that heatwaves and pounding rain will become more frequent, snow cover is projected to contract -- and typhoons and hurricanes will become less frequent but more powerful.

Before the Industrial Revolution, levels of CO2, the principal greenhouse gas, stood at around 280 parts per million (ppm). Today, CO2 concentrations are around 380 ppm and are rising between two and three ppm per year as big energy-gobbling countries, such as China and India, pursue their economic rise.

EDIT

In this latest assessment, the draft forecasts what temperature rise can be expected according to the CO2 scenario, but without mentioning the 2100 timeframe. With CO2 at 550ppm, average global temperatures would be between 2 and 4.5 C (3.6-8.1 F) higher than pre-industrial times, "with a best estimate of about 3 C (5.4 F)," says the report. It warns, though, that "values substantially higher than 4.5 C (8.1 F) cannot be excluded" if CO2 concentrations also rise significantly.

EDIT

http://www.terradaily.com/2006/070130141342.sks9ba1i.html

[kestrel91316]

1. Wonder how soon we'll have a new record high of 127 here in

Los Angeles County.......................

OMG

[NNadir]

2. I cannot believe we are even discussing 550 ppm.

That is purely insane.

[Systematic Chaos]

3. Insane, yes. Likely, um... yes.

And by that time Vegas will be seeing the 140's in low-lying areas of the valley and 130+ at the airport.

In other words, this will be a real cool ruin to come visit between November and April, nothing more.

[Dead_Parrot]

4. How do you mean, insane?

On the grounds it's a foregone conclusion we'll hit at least 600, you mean?
:shrug:
There was a thread in GD a week or so ago, with a prediction of of a 3ppm hike for this year: keep that up and it's only ~50 years to 550.

My daughter's gonna be annoyed. Hopefully, If I'm still around, I'll be too pissed and senile to notice.

:(

[Dogmudgeon]

5. The speed of the increase is itself increasing

I think the current rate of increase is over 2 ppm per year, double the rate in the 1990s, and it is accelerating. We're in terra incognita now.

We could be at 550 ppm in a decade or two. However, I strongly suspect that there will be negative feedback mechanisms kicking in, real hard and nasty. It almost sounds like a porn movie, right? However you look at it, it will be obscene.

A couple of degrees of temperature isn't a big deal. The big deal comes from what all that energy in the atmosphere will do to our ability to stay warm, dry, and fed.

--p!

[Dead_Parrot]

6. Umm, Pid...

It's a couple of degrees average, not a couple of degrees everywhere.



Goodbye rainforests, hello starvation and death. And the Hadley CM3 is starting to look like the essence of optimism...

[phantom power]

7. You just did that with air-brushing.

It's a joke, right? A funny...
:puke:

[Nihil]

8. _ _ _ _!

(Fill in the missing letters.)