NCAR Study - CO2 May Have Twice Or More The Effect On Global Temps Currently In Models

[hatrack]

If carbon dioxide emissions continue at their current rate through to the end of this century, atmospheric concentrations of the greenhouse gas will reach levels that existed about 30 million to 100 million years ago, according to Jeffrey Kiehl from the US National Centre for Atmospheric Research (NCAR). In a Perspective article in Science, Kiehl describes how he examined the relationship between global temperatures and high levels of carbon dioxide in the atmosphere tens of millions of years ago. Global temperatures then averaged about 16 °C above pre-industrial levels.

The article pulls together several recent studies that look at various aspects of the climate system, while adding a mathematical approach by Kiehl to estimate average global temperatures in the distant past.

The study found that carbon dioxide may have two times or more the effect on global temperatures than currently projected by computer models of global climate. The world's leading computer models generally project that a doubling of carbon dioxide in the atmosphere would have a climate feedback factor (ratio of change in surface temperature to radiative forcing) in the range of 0.5 to 1.0 °C per watts per square metre.

However, the published data show that the comparable climate feedback factor of carbon dioxide 35 million years ago amounted to about 2 °C per watt per square metre. "This analysis shows that on longer time scales, our planet may be much more sensitive to greenhouse gases than we thought," Kiehl says. Climate scientists are currently adding more sophisticated depictions of ice sheets and other factors to computer models. As these improvements come online, Kiehl believes that computer models and the paleoclimate record will be in closer agreement, showing that the impacts of carbon dioxide on climate over time are likely to be far more substantial than recent research has indicated.

EDIT

http://environmentalresearchweb.org/cws/article/news/44990

[NickB79]

1. If that's true, it's pretty much game over for us

We're already at 400ppm, and if that will actually have the same effect eventually as 800ppm in our current climate models, we're past the point of no return.

[joshcryer]

2. This is obviously assuming feedbacks.

We can still stop those feedbacks from entering a no-return phase. But barely. We don't have much time left at all.

[Nihil]

3. Errr ... "Oops"?

Looks like our best bet is to hope that he made a mistake in his calculations
or assumptions as - on the face of it - that is a pretty devastating conclusion.

:wow:

[Bigmack]

4. So much for the quaint note

that ours is a "sapient" species..... Ms Bigmack

[guardian]

5. let's see

he admits his models may be wrong by as much as 100%. Wow that inspires confidence. Of course, you'll never hear a doomer say that his model OVER estimate negative impacts. Apparently they only know how to UNDER estimate. Though it is a good technique to keep the public alarmed and the grant money rolling in.

[pscot]

6. Just for the record

Do you see anything happening around you that suggests there might be some trouble ahead for ourselves and our fellow critters? Do you deny that the place is heating up? That the oceans are a mess; That the weather is a tad unusual; that we're low on oil; that food insecurity is increasing? Do you think it doesn't matter? Do you think science in general is a scam, or just climate science? If you have anything positive to say I, for one, would love to hear it. Impugning the motives of people who do the grunt work isn't really much of an argument, is it?.

[joshcryer]

7. Record highs and lows on the temperature record? Most in the past decade.

Fun times ahead.

[hatrack]

9. Does it live under a bridge? Does it wield a club? Does it hate goats?

:rofl:

[guardian]

10. You're right

impugning the motives of researcher distracts from the key point that

his climate model is pure crap!

By his own admission it is off by 100%. This means that an objective third party will find it is off by some greater amount. If you want to pin your hopes, dreams, and fears to work like this go ahead. Me...I sleep like a baby.

[pscot]

11. Thanks for responding

You need to think more like Ray. Synthesize.

[XemaSab]

8. .

:popcorn: