Oil's energy contribution has declined by about 12% since 1999. The world's economies have also declined by about 12%. (Using conventional metrics, which are time delayed determinations, this will only be seen in hind sight). The massive destruction of asset values now occurring testifies to it happening.
Peak is well behind us, world economies have peaked and will continue to decline.
Joined: Aug 03, 2007 Posts: 4609 Location: Boston Suburbs
Posted: Sat Sep 27, 2008 12:33 am Post subject: Re: Runaway Global Warming - Has Arrived
Hermes wrote:
The global average temperature has been higher than it currently is before, right? Why wasn't life extinguished from the planet at that point then?
Because the planet could still support some life, just a lot LESS than the previous climate. It would really take a lot to completely wipe out all life up to and including single celled organisms like the extremophiles that live in the ocean vents. _________________ http://doomsteaddiary.blogspot.com/
Joined: May 27, 2007 Posts: 1776 Location: The Post Peak Oil Historian
Posted: Sat Sep 27, 2008 12:37 am Post subject: Re: Runaway Global Warming - Has Arrived
"It is impossible to talk about a single temperature for something as complicated as the climate of Earth", Bjarne Andresen says, an an expert of thermodynamics. "A temperature can be defined only for a homogeneous system. Furthermore, the climate is not governed by a single temperature. Rather, differences of temperatures drive the processes and create the storms, sea currents, thunder, etc. which make up the climate".
He explains that while it is possible to treat temperature statistically locally, it is meaningless to talk about a a global temperature for Earth. The Globe consists of a huge number of components which one cannot just add up and average. That would correspond to calculating the average phone number in the phone book. That is meaningless. Or talking about economics, it does make sense to compare the currency exchange rate of two countries, whereas there is no point in talking about an average 'global exchange rate'.
If temperature decreases at one point and it increases at another, the average will remain the same as before, but it will give rise to an entirely different thermodynamics and thus a different climate. If, for example, it is 10 degrees at one point and 40 degrees at another, the average is 25 degrees. But if instead there is 25 degrees both places, the average is still 25 degrees. These two cases would give rise to two entirely different types of climate, because in the former case one would have pressure differences and strong winds, while in the latter there would be no wind.
Many averages
A further problem with the extensive use of 'the global temperature' is that there are many ways of calculating average temperatures.
Example 1: Take two equally large glasses of water. The water in one glass is 0 degrees, in the other it is 100 degrees. Adding these two numbers and dividing by two yields an average temperature of 50 degrees. That is called the arithmetic average.
Example 2: Take the same two glasses of water at 0 degrees and 100 degrees, respectively. Now multiply those two numbers and take the square root, and you will arrive at an average temperature of 46 degrees. This is called the geometric average. (The calculation is done in degrees Kelvin which are then converted back to degrees Celsius.)
The difference of 4 degrees is the energy which drives all the thermodynamic processes which create storms, thunder, sea currents, etc.
link _________________ In a time of universal deceit, telling the truth is a revolutionary act. - George Orwell
It riles them to believe that you perceive the webs they weave. - Moody Blues
Posted: Sat Sep 27, 2008 5:38 am Post subject: Re: Runaway Global Warming - Has Arrived
That was a maybe 10 g of Methane. Now multiple that by say 100 for 1 kg of Methane. Then by another 1,000 for 1 tonne of methane and then by say 3,000 for 3 million tonnes of Methane released in the Arctic this year.
So then we have 10g x 100 = 1 kg x 1,000 = 1 tonne x 3,000 = 3 million tonnes.
Anybody want to put a match to that and be anywhere near?
Joined: Nov 20, 2004 Posts: 163 Location: Land of the Tonkawa/Karankawa
Posted: Sat Sep 27, 2008 7:48 am Post subject: Re: Runaway Global Warming - Has Arrived
mos6507 wrote:
Hermes wrote:
The global average temperature has been higher than it currently is before, right? Why wasn't life extinguished from the planet at that point then?
Because the planet could still support some life, just a lot LESS than the previous climate. It would really take a lot to completely wipe out all life up to and including single celled organisms like the extremophiles that live in the ocean vents.
Joined: Nov 20, 2004 Posts: 163 Location: Land of the Tonkawa/Karankawa
Posted: Sat Sep 27, 2008 8:04 am Post subject: Re: Runaway Global Warming - Has Arrived
Cid_Yama wrote:
"It is impossible to talk about a single temperature for something as complicated as the climate of Earth", Bjarne Andresen says ...
link
Cid:
First of all thanks for answering my question. (and Mos, thanks as well... I forgot to mention.)
Trying to understand what you're putting forth here: You're saying that talking about the global average temperature isn't very useful as its measurement can be deeply flawed. And furthermore you're saying that an average global temperature is probably not too useful to talk about anyways because it is such a gross oversimplification of the situation that it renders the numbers meaningless.
Did I get that right?
At the same time we are talking about Global Warming, right? The idea is everyone's trying to figure out what is going to happen to the earth when it's warmer. There needs to be some useful way that we can talk about the amount of warming, amount of C02 in the atmosphere... something in order to have a discussion about it, right?
Either people agree that global temperature isn't a useful indicator of what effects GW will have... and then these predictions of what its temperature-based effects will be are highly questionable... OR people agree that global temperature IS an indicator of what GW's effects will be and then I'm back to my question of why it is that the earth has been much warmer in the past and life has thrived through the period.
Do you follow me? _________________ Collapse-prep Intentional Community forming outside of Austin, TX. PM me if interested.
Posted: Sat Sep 27, 2008 8:05 am Post subject: Re: Runaway Global Warming - Has Arrived
Hermes wrote:
mos6507 wrote:
Hermes wrote:
The global average temperature has been higher than it currently is before, right? Why wasn't life extinguished from the planet at that point then?
Because the planet could still support some life, just a lot LESS than the previous climate. It would really take a lot to completely wipe out all life up to and including single celled organisms like the extremophiles that live in the ocean vents.
---------------------------
Mean atmospheric CO2 content over period duration:
ca. 1700 ppm (6 times pre-industrial level)
Mean surface temperature over period duration:
ca. 18 °C (4 °C above modern level)
---------------------------
And I believe life was pretty vibrant during the period, right? Including many gigantic dinosaurs and such.
What am I missing here?
What is being missed here is the rate of change. It's the ability of life to adapt to, or migrate within a changing environment that determines it's survival. This is determined by by the degree of biodiversity, the mobility of habits and the availablity of migration corridors. Even in the best case, adaptation takes time, if the rate of change is too great (or comes from multiple directions) it means extinction is the most probable outcome.
You also have to take into account the Earth today is quite different to the Earth of the Cretaceous era, plate techtonics has significantly rearraged the placement of land mass. Furthermore, the solar output has increased as the Sun matures. It's not as simple as taking the average temperature and CO2 concentration, and comparing directly with the modern Earth.
Joined: May 27, 2007 Posts: 1776 Location: The Post Peak Oil Historian
Posted: Sat Sep 27, 2008 8:21 am Post subject: Re: Runaway Global Warming - Has Arrived
Let's revisit the Cretaceous for those thst missed it.
Concentration of carbon dioxide in the Late Cretaceous atmosphere
Stable carbon isotope data from Late Cretaceous (Maastrichtian) palaeosols in India are used to estimate the concentration of carbon dioxide in the Late Cretaceous atmosphere. We show that the Maastrichtian atmosphere is unlikely to have contained more than about 1300 ppm by volume of CO2.This value agrees with an independently modeled value of CO2 in the Late Cretaceous atmosphere.
link
Gradual global warming, induced by flood basalt volcanism, may trigger the sudden release of methane hydrate and a positive feedback mechanism that in turn may cause catastrophic climate change and extinctions. This is the scenario suggested by the sharp negative d13C spike for the early Toarcian (Hesselbo et al., 2000). Methane hydrate release, first invoked to account for the late Paleocene thermal maximum (Dickens et al., 1995), has also been considered for the Permian-Triassic event (Erwin, 1993; Krull and Retallack, 2000).
link
New research challenges the generally accepted belief that substantial ice sheets could not have existed on Earth during past super-warm climate events. The study by researchers at Scripps Institution of Oceanography at UC San Diego provides strong evidence that a glacial ice cap, about half the size of the modern day glacial ice sheet, existed 91 million years ago during a period of intense global warming. This study offers valuable insight into current day climate conditions and the environmental mechanisms for global sea level rise.
A micrograph of two types of foraminifera, M. sinuosa and W. baltica used to study climate conditions during the Cretaceous Thermal Maximum, 91 million years ago.
The new study in the Jan. 11 issue of the journal Science titled, "Isotopic Evidence for Glaciation During the Cretaceous Supergreenhouse," examines geochemical and sea level data retrieved from marine microfossils deposited on the ocean floor 91 million years ago during the Cretaceous Thermal Maximum. This extreme warming event in Earth's history raised tropical ocean temperatures to 35-37°C (95-98.6°F), about 10°C (18°F) warmer than today, thus creating an intense greenhouse climate. link _________________ In a time of universal deceit, telling the truth is a revolutionary act. - George Orwell
It riles them to believe that you perceive the webs they weave. - Moody Blues
Joined: Nov 20, 2004 Posts: 163 Location: Land of the Tonkawa/Karankawa
Posted: Sat Sep 27, 2008 8:46 am Post subject: Re: Runaway Global Warming - Has Arrived
Cid:
I'm sorry, as this must be frustrating for you: you seem to have studied this matter a great deal. Thanks for your patience.
Let me put things another way...
I fully accept that GW will (in conjunction with PO) almost certainly wipe out 95% of the world's human population. I also believe that GW will wipe out a number of non-humans as well. I get that.
The piece I'm trying to figure out now is if it's truly "Runaway GW" at this point.
During this earlier period when it was a full 10 degrees C warmer than today wouldn't a really PROFOUND amount of methane have been released into the atmosphere also? And wouldn't that amount of methane have quite easily wiped out all life on earth?
Yet it didn't.
Is having methane being locked away under the earth a geologically new thing? Like has it only occurred over the past few million years? That must not be the case right, b/c of the assumption of methane release triggering the P/T extinction event, yes?
When the 4GT methane burp happened back during the P/T extinction event, triggering more methane release and bringing the global average temperature up 30 degrees F... why did it stop at 60 degrees? Why didn't it keep going to some far higher temperature?
Is the assumption that there was far less methane around to be released? or what?
Thanks again. _________________ Collapse-prep Intentional Community forming outside of Austin, TX. PM me if interested.
Posted: Sat Sep 27, 2008 8:54 am Post subject: Re: Runaway Global Warming - Has Arrived
Hermes wrote:
Something I'm missing in this, which hopefully someone can help me put together:
The global average temperature has been higher than it currently is before, right? Why wasn't life extinguished from the planet at that point then?
What am I missing?
A couple of points, the current methane release we are seeing is not from the continental shelf clatherates. They will require a huge amount of additional heating before about 1km of water is heated enough that they start melting. What we are seeing at the moment is the melting of shallow water clatherates in the arctic ocean. The arctic has been ice covered for the past 3 million years when the Panama Ismuth closed. Clatherates form when ice on the sea bed traps the natural release of methane from bacteria. The current existance of such shallow clatherates on the arctic floor may not be all that old. Before the forming of the icecap it is possible that it was too warm for clatherates to form that shallow.
It did cause a mass extinction though. It seems to take a confluence of factors to cause something along the lines of the Permian Triassic extinction. Some people are arguing that we have a similar confluence.
Posted: Sat Sep 27, 2008 9:02 am Post subject: Re: Runaway Global Warming - Has Arrived
Hermes wrote:
During this earlier period when it was a full 10 degrees C warmer than today wouldn't a really PROFOUND amount of methane have been released into the atmosphere also? And wouldn't that amount of methane have quite easily wiped out all life on earth?
Yet it didn't.
Clatherates are temperature sensitive. So if the overall globall temperature is 10C warmer, the seas will be warmer and the clatherates will have to form much deeper. A reasonably slow change in temperature will slowly melt clatherates. This will be a minor event as methane decomposes in the atmosphere very quickly. What seems to trigger the 'burrps' is a rapid change in climate temperature where the methane melts so quickly it can build up in the atmosphere.
Joined: May 27, 2007 Posts: 1776 Location: The Post Peak Oil Historian
Posted: Sat Sep 27, 2008 9:18 am Post subject: Re: Runaway Global Warming - Has Arrived
When the 4GT methane burp happened back during the P/T extinction event, triggering more methane release and bringing the global average temperature up 30 degrees F... why did it stop at 60 degrees?
You are confused.
The 4 GT and 30-60 F figure is the estimate for the end of the ice age 15,000 years ago, not the Permian-Triassic extinction.
No methane cascade happened at that time as the release was relatively minor and the planet was in an ice age at the time.
Let's revisit the Permian-Triassic Extinction:
The most accepted view(and the one supported by the geological record) is that widespread vulcanism in the Siberian Traps released massive amounts of carbon dioxide causing global warming which triggered a release of subsea methane, initiating runaway global warming.
This massive release of carbon into the atmosphere reduced atmospheric oxygen from 35% to 12%.
This combined with ocean acidification caused by the high carbon levels created an anoxic ocean.
Sulphate-reducing bacteria in the anoxic ocean produced hydrogen sulphide which combined with low atmospheric oxygen levels intitiated a catastrophic release of hydrogen sulphide into the atmosphere.
Fungi were the dominant life form on the planet for the next several millions of years. _________________ In a time of universal deceit, telling the truth is a revolutionary act. - George Orwell
It riles them to believe that you perceive the webs they weave. - Moody Blues
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