Comments on: Feedback Assumptions Finally Being Challenged

By: maxwell

maxwell — Thu, 04 Feb 2010 15:55:17 +0000

Maj. Combs, where does the forcing due to one CO2 molecule come from? I get the use of Steffan-Boltzmann equation, but how does one calculate the forcing due to CO2 molecule by molecule? I’m not asking to be nit-picky, I’m just curious. From a molecular perspective, it seems like something that is hard to quantify because it depends on the density of other molecules, inter-molecular collision rates and even chemistry if it’s happening. Thanks.

By: FollowFacts

FollowFacts — Wed, 03 Feb 2010 19:26:50 +0000

Putting the CO2 effect by itself into context:

Doubling CO2 has about the same effect (in average temperature) as moving from Boston, MA to New York City, NY. And that is using the high end of the estimate for CO2 doubling (1.5 C).

CO2 doubling has about half the effect of moving from Boston to Washington, DC.

The rest of the bogeyman is feedback and its net sign.

By: Michael B. Combs, Major USAF Retired

Michael B. Combs, Major USAF Retired — Wed, 03 Feb 2010 02:13:31 +0000

Maxwell – If nothing changes other than temperature, the response is straightforward. Emissions in general are proportional to the fourth power of temperature, and on Earth, with surface temperatures of about 288K and emissions to space of about 240 W/m2, we get about 0.3C for each W/m2 forcing. You can nail that down more carefully, but it does correspond closely to what you get with a radiation transfer calculation. It’s called the “Planck response” in climate science. Converting forcing units, this corresponds to about 1.1C per doubling of CO2.
Recent periods of greater warming than present, the Medieval Warm Period (800 to 1300 AD) being the most recent, did not trigger out-of-control warming. On the contrary, the Medieval Warm Period was followed by the Little Ice Age (1300 to 1850 AD), following the pattern of alternating warming and cooling observed several times since the end of the Ice Age just over 10,000 years ago. In none of these temperature fluctuations was CO2 a factor, and if anything, the feedbacks to rising temperature apparently were net effect negative, not positive. The proof? No runaway warming.
In terms of catastrophes, the warm periods exhibited the greatest advances in human civilization, and the cold (best documented: the Little Ice Age and, to a lesser extent, the Dark Ages) were characterized by crop failures, famine, violent storms, disease and pestilence, glaciation, and other adverse effects of cooling to vex mankind.
The greater warming experienced during the Medieval Warm Period requires no examination of tree rings or ice cores, only the observation of natural phenomena: Vineyards flourished in England where they can’t today. Greenland Viking farms are still in permafrost today. Tree lines were 1,000 feet higher. Glaciers were less extensive. The Little Ice Age reversed all that.
Hundreds of climate studies by thousands of researchers in over 40 countries and on all continents have also established the Medieval Warm Period as global and as warmer than the present. They just confirm what Mother Nature so abundantly and clearly demonstates – climate change is natural, and the peer review is all around us.

By: Harrywr2

Harrywr2 — Tue, 02 Feb 2010 22:21:45 +0000

Restiches,

“How can forests absorb less or give off more CO2? ”

At some point trees become heat stressed and die off, of course their rotting corpses give off ‘green house’ gas.
There have been differing studies on this. There was a study just today that East Coast trees are loving the new environment, there has also been a study that west coast trees hate it.

Orginal Topic
“Of course, because if this factor goes down, they will just shore up their forecasts and keep them them high with some other plug variable.”

I think there is a scramble to identify ‘why it’s not warming as much’ at the moment. Better to toss out of few papers ‘correcting’ the trend then let the trend completely falsify the ‘previous’ research.

By: Alan D. McIntire

Alan D. McIntire — Tue, 02 Feb 2010 01:10:49 +0000

In response to Wally:

Some data I picked up surfing the internet:

“Glaciation
For a number of reasons, the volume of glacial ice near the poles
waxes and wanes over time. As a result, water is alternately taken from or added to the world oceans. This can result in sea-level oscillations of up to 200 meters. For example, modern continental glaciers are 1.5 to 2.5 km thick and have a total estimated volume of 33 million km3. If we assume the maximum volume of Pleistocene glaciers to have been 71.3 million km3, Flint, 1971 then the difference is 38 million km3. Using the assumption that glacial water volume is 91.7% of the volume of sea water from which it is derived, a sea-level drop of 106 m can be accounted for by Pleistocene glaciation. Melting of the present Greenland and Antarctic glaciers would produce a sea-level rise of approximately 60 meters.

The specific latent heat of fusion of ice at 0 ºC, for example, is 334
kJ.kg-1. This means that to convert 1 kg of ice at 0 ºC to 1 kg of water at 0 ºC, 334 kJ of heat must be absorbed by the ice. Conversely, when 1 kg of water at 0 ºC freezes to give 1 kg of ice at 0 ºC, 334 kJ of heat will be released to the surroundings.

“The total mean mass of the atmosphere is 5.1480×1018 kg with an
annual range due to water vapor of 1.2 or 1.5×1015 kg depending on
whether surface pressure or water vapor data are used; somewhat
smaller than the previous estimate. The mean mass of water vapor is
estimated as 1.27×1016 kg and the dry air mass as 5.1352

A 4C rise or higher this century would see the world warm almost as
much in 100 years as it did during the 15,000 years since the end of
the last ice age.”

Putting it all together, 71.3 million k3 ice *0.917 vol ice/vol
water= 65.3821 million cubic kilometers of water.

1 cubic meter= 1000 kg.
1 cubic km = 10^12 kg
65.3821 million cubic km= 65.3821*10^18 kg

Total heat to melt glaciers =65.3821 *10^18 *1000*334 kj=2.18*10^25
joules

Cp air= 1.012 joules/gram K
1012 Joules/kg K * 5.148^10^18 =5.209776 *10^21 joules

4degree increase=2.0839 *10^22 joules

So about 1000 times as much heat went into melting the glaciers at
the end of the Pleistocene as went into heating the atmosphere. Figure that the ice had to start melting before temperatures went up, and that there would be positive feedbacks due to changes in Earth’s albedo after the continental glaciers melted, CO2 must have had only a negligible feedback effect. Tilde Guillemet and Hans Erren have demonstrated that the AGWers who originally hypothesized a 1C increase for a 10 ppm increase were incompetent pseudoscientists- A. McIntire

- A. McIntire

By: Chris

Chris — Mon, 01 Feb 2010 22:24:29 +0000

Off topic, but this is interesting

http://bastardoldholborn.blogspot.com/2010/02/bbc-and-climate-change.html

By: Wally

Wally — Mon, 01 Feb 2010 21:30:45 +0000

Can someone please explain to me how the authors get around the whole problem of correlation doesn’t mean causation? There might have been forces driving CO2 and warming together, thus CO2 may not drive temperature, and any multiplier is not causal but just a correlation factor. For example, the front wheels of my car always lead the back wheels while in drive, but the front wheels are not actually providing the energy to move the back wheels forward. Its actually the engine in my car driving both sets of wheels, there is just a positional lag (distance between) the front and the back wheels.

By: Hans Erren

Hans Erren — Mon, 01 Feb 2010 21:29:50 +0000

Me first, me first:
i wrote this already in 2002 !!

“The response of co2 on temperature is approximately 10 ppm/degC

Quick and dirty approach:

Vostok ice core:
minco2 183.9 ppm
maxco2 299.5 ppm
mintemp -8.49 degC
maxtemp 3.26 degC

temprange 11.75 degC
co2range 115.6 ppm

response 9.838298 ppm/degC”

http://members.casema.nl/errenwijlens/co2/howmuch.htm

By: Tilde Guillemet

Tilde Guillemet — Mon, 01 Feb 2010 04:01:48 +0000

The number they came up with for CO2 release against temperature has been obvious for a long time.

Vostock Ice cores show a temperature range of -8C to +2C between ice-age and warm period (roughly).

CO2 range is 180ppmv to 280ppmv. So 100 ppmv difference for 10C means a multiplier of 10ppmv per degree C.

Can I have my Nobel Prize now please?

By: aqz

aqz — Mon, 01 Feb 2010 03:32:25 +0000

re: Restiches.

Plants use photosynthesis to store energy, as sugars and starches, a process which absorbs carbon dioxide.

Plants respire to use the stored energy, a process which emits carbon dioxide.

The stored energy is used for tissue and cell growth.