Runaway Global Warming - Has Arrived pt 7

[rockdoc123]

In either case human made GHG are emitted with the potential to induce a run-away effect, which would magnify any natural trend to global warming.

Energyspin I think that this is slightly misleading, yes it is possible based on models that positive feedback could result in the runaway effects you speak of......what is somewhat irksome is that no one seems to be willing to address the potential for negative feedback which could result in the exact opposite effect....global cooling (eg. melting glaciers creates additional water vapor creates clouds blocks sunlight cools earth). We have to remember that the so-called butterfly effect can make systems change in either direction.

Point being the whole feedback argument is based on extremely poorly constrained models....if you can't define parameters for each and every one of the variables then it is pretty hard to predict with any certainty what will happen.

And again your facts on CO2 are incorrect....yes overall CO2 levels have increased by the percentage you mention. However anthropogenic CO2 accounts for only ~3% of the overall CO2 in the atmosphere (and overall CO2 accounts for only ~3% of greenhouse gases).....something else is going on as well to elevate these levels.

[EnergySpin]

In either case human made GHG are emitted with the potential to induce a run-away effect, which would magnify any natural trend to global warming.

Energyspin I think that this is slightly misleading, yes it is possible based on models that positive feedback could result in the runaway effects you speak of......what is somewhat irksome is that no one seems to be willing to address the potential for negative feedback which could result in the exact opposite effect....global cooling (eg. melting glaciers creates additional water vapor creates clouds blocks sunlight cools earth). We have to remember that the so-called butterfly effect can make systems change in either direction.

Point being the whole feedback argument is based on extremely poorly constrained models....if you can't define parameters for each and every one of the variables then it is pretty hard to predict with any certainty what will happen.

And again your facts on CO2 are incorrect....yes overall CO2 levels have increased by the percentage you mention. However anthropogenic CO2 accounts for only ~3% of the overall CO2 in the atmosphere (and overall CO2 accounts for only ~3% of greenhouse gases).....something else is going on as well to elevate these levels.

Rockdock ... I agree with your assessment of the butterfly effect, unfortunately the 3 mechansims that I wrote are real and the (-) feedback mechanisms that have been reported that would work in a corrective manner are not keeping up with what is going on (natural or human or both). Negative feedback mechanisms do not lead to runaway effects by definition, I guess you wanted to say: positive feedback mechanisms leading to cooling. However think about what you are saying now: lets burn it fast so we can approach the point where a corrective mechanism is triggered. Such rapid changes in climate , in either direction, have been associated with extintiction events in the past. Is this a prudent course?
Sounds like homeopathic medicine to me and till people come up with such mechanisms I would rather err on the safety side.

Your are making the assumption/calculation that FF only account for 3% of the total CO2 emitted in the atmosphere. Even this is true (though other members here would disagree with you) .. you have to acknowledge that there are indirect effects as well (i.e. change in land use etc) that were made possible by FFs. For example intensive agriculture leads to loss of carbon sequestration by the soil. If it had not been for FFs we would not have had modern agriculture (and this change is land use might be a bigger player than we think).

[backstop]

EnviroEngr wrote:
I've been told by some geologists and archaeologists that we're still coming out of the last Ice Age - that what we're going through now isn't a shift to a new equilibrium but a finishing off of the last cycle. True ?

EE –

On balance I’d say no its not true, at least not in a scientific sense.

Firstly, recent ice ages have been exceptional in the Earth’s history over geological time and have not run according to a fixed time period. As they’ve varied in length, it would seem rash to forecast just where we are in the cycle, or what would happen millennia hence if society were not now perverting the course of climate evolution.

However, it is generally accepted that we are in an “inter-glacial” period, on the assumption that from here on over the next 10,000 years or so the planet would, if left to its own devices, head back into an ice age.

This was the basis of two scientists’ report in the ‘70s, that we are at the mid-point between two ice-ages, assuming that this interglacial would be of similar length to the last.

That report was picked up, distorted, re-written, sensationalized and well-hyped by the press as: “We’re heading into an ice-age.”

Since then those press distortions have in turn been sicked-up by the fossil fuel lobby’s paid advocates as a means to try to smear climate scientists in general to try to prevent the public recognizing the rising hazard of climate destabilization.

To the extent that the planet is littered with fading relics of the last ice age, such as land-masses rising from where they were depressed by massive ice-sheets, and tundra lichen species still enduring in the Scottish highlands, it is of course quite reasonable to say that “we’re still coming out of the last Ice Age.”

Hope this at least gives your question some useful context.


Regards,

Backstop

[Devil]

Normally, I never look at Open Discussion because I don't have time to sort out the 0.1% wheat from the 99.9% chaff. However, I have been asked my opinion, which I'm sure is already well-known.

IMNSHO, climate change is for real and is caused by a combination of many tens of factors, some anthropogenic, some natural. The premafrost problem is just one of many results.

However, I invite sceptics to consider two things:
1. delta T/delta t
As far as is known, there has never been a natural global temperature change as fast as this one, short of some very major catastrophic event. Why should this be, when there is no factor to explain it?
2. The coincidence of the anthropogenic GHG concentration curve with the temperature curve.



It can be seen from these curves that natural forcing over recent years should have actually produced a negative temperature tendency. This has been countered by the 5 billion tonnes of carbon we are adding to the atmosphere each year ONLY from burning fossil fuel, of which 3 billion tonnes are "sticking" cumulatively. It is this that has caused CO2 concentrations to rise 43% from 280 ppm to 400 ppm over the last 150 years and never has the rate of rise been so great. Even more alarming, CH4 levels have risen 125% from 800 ppb to 1800 ppb in the same time, again from anthropogenic sources, especially from natural gas exploitation, rice paddies (countered by marsh drainage) and enteric fermentation.

I don't have time to write a book on the subject here, any more than you have the time to read it, but you can see some of my views in a series of essays at http://www.cypenv.org/ .

In particular, I draw your attention to the worst fossil fuel of the lot at http://www.cypenv.org/world/Files/methane.htm . This essay is not yet finalised, but the facts are there.

Finally, on a UK netlist, a member recently posted a comment on the "new" US "policy" on climate change. You can see his message and my response at http://www.bnellis.com/phpBB2/viewtopic.php?t=19 with a list of the measures which I think will be necessary to at least stabilise the carbon cycle.

Note that I shall not be monitoring any replies on this forum.

[Specop_007]

Ludi –

........
At the point where all the feedback loops’ combined output swamped the planet’s cleansing ability (~2.3Bn Ts C /yr), the loops would become effectively self-fuelling and entirely beyond any human remedy. Given the momentum of the massive elemental forces in play, we may already be committed to that condition – each day wasted in the status quo’s prevarication makes it more likely.
.......
Regards,

Backstop

Man, I dunno how serious that is, but it sure does sound frickin scary.

[Liamj]

Shocking news. Whats to say? When liars still lead.

[Ludi]

Backstop, I'm afraid I don't share your optimism about Washington. This news should be the top story in all papers and news shows. Is it? Probably not.

To me, this news about the permafrost is devastating, far scarier than peak oil. But I've posted this story at other sites and, guess what -

nobody cares.

They just argue about if it is anthropogenic or not, and say "well, the Earth has been through other climate changes."

They don't realise that civilized man has never been through a major climate change. Even the "little ice ages" were extremely hard on civilized societies, with widespread famine, and those were quite mild events.

Ignorance is bliss and unfortunately the majority of Americans are hopelessly ignorant and determined to stay that way. And that's just the way those in power want them to be.

[Z]

However anthropogenic CO2 accounts for only ~3% of the overall CO2 in the atmosphere (and overall CO2 accounts for only ~3% of greenhouse gases).

Would you like to try to backup your claims with some source, please ? And no, websites from lobbysts with an obvious agenda don't count.

CO2 concentration has risen 36% since the end of the 19th century, and reached levels not seen for a very long time ( records indicate that since 400,000 years the maximum concentration reached was 300ppm, compared to today's 380 ppm and rising ). Gee, I wonder what changed between several 100,000's years ago and the last 100 years ?

Here are the numbers I got concerning the effects of greenhouse gases on the overall greehouse effect :

H2O - 55% caused by 0.3% of atmosphere
CO2 - 40% caused by 0.038% of atmosphere
CH4, N2O, O3 - 2% caused by 0.00018%, 0.00003%, 0.000003% of atmosphere

Different gases have different impacts on the greenhouse effect. Even if CO2 was 3% of greehouse gases ( more like 10% actually ), it does not follow that CO2 accounts for 3% of the greenhouse effect.

Even if anthropogenic CO2 only account for 3% of overall emissions, the Earth biosystem cannot absorb more than half of that extra emissions. This CO2 will accumulate in the atmosphere and strengthen the greenhouse effect. Even if anthropogenic CO2 is such a small part of overall CO2 emissions, man's activities still can result in an increased greenhouse effect in the long term.

[americandream]

I'm doing a poll on what the breakdown is between those who see climate change as likely, those who don't, those who don't know and those who are downright sceptical of the notion........

.........in a nutshell are we, in running the civilisation we are, heading for the cliff edge climatically?

Thanks for your time.

[Peak_Plus]

How do you define "terminal?"

[MadMarcus]

How do you define "terminal?"

I'm with Peak_Plus. While I answered the question I really have no faith in my answer without knowing how you define terminal.

I do not think climate change will render the Earth uninhabitable

[Doly]

I'm assuming that "terminal" in this context means a change big enough to cause havoc with our current crops.

I really don't know. I used to think it was unlikely, but recent informations seem to point that it is a real possibility. I wish things were clearer.

[Rincewind]

Hmm Terminal sounds very final

Life is a lot more resilent than we generally think. I was once told that about the only way to wipe out on Earth was for the sun to go Nova, as there are bacteria living happily in the crust.

So for me their is a heirarchy something like:

1 End of current world order (you know the US, EU, Russian Fed, China dominated world)
2 End of technocratic civilisation (hygiene, easy information transfer)
3 End of humans as the dominant species (Yes I know the bacteria really run the planet but you know what I mean)
4 Human species extinct
5 Chordates extinct (things with backbones)
6 Invertbrates extinct (cockroaches)
7 Life extinct

On this scale the worst I can conceive of as a result of climate change is about level 3 basically back to a population of under 1 million dominated by hunter/gather and slash and burn subsistance agriculture (but this would take centuries/millenia). 1 I think is inevitable and 2 is [highly] possible.

Rincewind

[americandream]

"Terminal" here meant a point at which the climate soup flips over into a rapid imbalance that is no longer friendly to life.........the underlying notion being.....that there are drivers present today with uniquely intensive co2 output profiles, namely, this civilisation.

Does anyone know of an equivalent open ended co2 input mechanism in past planetary history.

[Tanada]

"Terminal" here meant a point at which the climate soup flips over into a rapid imbalance that is no longer friendly to life.........the underlying notion being.....that there are drivers present today with uniquely intensive co2 output profiles, namely, this civilisation.

Does anyone know of an equivalent open ended co2 input mechanism in past planetary history.

As a matter of fact, yes. During the great glaciation "snowball earth" period 400 million years ago the ice sheets met at the equator and rainfall effectively stopped. Without rainfall the CO2 in the air was not absorbed by condensation drops and mixed with the surface waters of the earth, instead it continued to build up from volcanic sources for millenia, perhaps even a million years or more. Once the greenhouse effect grew intense enough to melt the equatorial portion of the ice sheet the surface waters rapidly warmed by absorbing solar energy. A feedback loop took effect and within less than a millenia all the surface ice on Earth melted from pole to pole. The open surface water released water vapor into the air and it started raining again, washing the CO2 out of the air into the surface waters and ocean. This resulted in a very thick limestone layer world wide, which is popular in geology field trips relating this scenario.

Do a search on the "snowball Earth" threory to see if I messed up any of the details from memory.

[smallpoxgirl]

Does anyone know of an equivalent open ended co2 input mechanism in past planetary history.

In all fairness, it's not open ended. These are fossil fuels. Every drop of gasoline was once a plant or something. Life survived on earth then, and it will continue into the forseable future. I like Rincewind's scale, and I would agree. #1 almost certain. #2 likely #3 maybe #4 unlikely.

[grabby]

People will be people.

[Ibon]

Think about bogs, swamps, river deltas, ocean bottoms or any such places where oxygen deprives organic matter from decomposing and it builds up hundreds or thousands of feet thick. Add time and pressure and it works just like heat and pressure on olives making olive oil.

[bobcousins]

So for me their is a heirarchy something like:

1 End of current world order (you know the US, EU, Russian Fed, China dominated world)
2 End of technocratic civilisation (hygiene, easy information transfer)
3 End of humans as the dominant species (Yes I know the bacteria really run the planet but you know what I mean)
4 Human species extinct
5 Chordates extinct (things with backbones)
6 Invertbrates extinct (cockroaches)
7 Life extinct

Great scale! A little non-linear of course, the jump from 6 to 7 is a lot bigger than 1 to 2, but useful.

#2 and possibly are #3 are inevitable anyway, even without global warming. In a few thousand years when the next glacial period starts (ice age in lay speak), civilisation is pretty much doomed. There will be 1km thick ice sheets covering much of Northern Europe for example. At the turn of the last ice age, it is speculated there were as little as 75,000 humans, based on genetic variations.

Even a current spell of up to +2 deg human induced warming pales into insignificance compared to the +12/-12 variation over the history of the Earth.

[americandream]

I guess to the extent that we tend to largely measure anything in terms of our presence on this planet...terminal here would mean liveability for the present ecosystem which has brought humankind to this point in its evolution.

Looking at the broader cosmic picture, I've no doubt that this planet has many an interesting detour to take before this particular solar system reaches its term.

In the presence of a co2 open ended civilisation such as ours.....(unlike many I'm not awfully sure that we have the ability to limit our drawdown of co2 from the planets reserves).......the question that comes to my mind is how long will the present ecosystem prevail before it flips to a state no longer friendly to the current crop of inhabitants. With an exponentially expanding co2 intensive global economy, it seems that time is not on our side.