AuthorTopic: Climate Science Questions  (Read 2862 times)

Offline JRM

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Climate Science Questions
« on: February 19, 2014, 02:52:08 PM »
Quote
“If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from [current levels] to at most 350 ppm.”
Dr. James Hansen

Quote
"Since the beginning of human civilization, our atmosphere contained about 275 ppm of carbon dioxide. That is the planet “on which civilization developed and to which life on earth is adapted.”  350.org website


I've been wondering of late just how -- and when -- Earth's climate system might stabilize at another global average temperature ... or maybe begin to cool?

Most climatologists and climate activists seem to be saying that if we were to radically reduce CO2 and other anthropogenic greenhouse gas emissions, thus reaching a plateau in the graph line of atmospheric GHG emissions -- and declining from there -- we should expect to avoid worst case scenarios.

Trouble is, there are some positive feedbacks already at work. For example, the Arctic sea ice albedo - http://en.wikipedia.org/wiki/Ice-albedo_feedback .

And

Quote
"Dissolution of CO2 into the oceans is fast but the problem is that the top of the ocean is “getting full” and the bottleneck is thus the transfer of carbon from surface waters to the deep ocean. This transfer largely occurs by the slow ocean basin circulation and turn over (*3). This turnover takes 500-1000ish years. Therefore a time scale for CO2 warming potential out as far as 500 years is entirely reasonable (See IPCC 4th Assessment Report Section 2.10)."

 ~ from
http://www.skepticalscience.com/co2-residence-time.htm

I'm wondering how long it should be expected to take -- under the ideal hypothetical condition of a complete and sudden cessation of all anthropogenic GHG -- for, say, the current (e.g.) atmospheric CO2 concentration of roughly 400 ppm to lower to the ostensibly safe target of 350 ppm?

Should this be expected to require centuries? And if so, what prevents global average temperatures from going up and up and up ... far beyond anything life as we know it can tolerate?

There appear to be more known positive feedback mechanisms than negative ones, with the known negatives being, apparently, much too weak to counteract the positives.

So I'm perplexed.  Scientists and climate activists say there is urgent work to be done to avert the worst.  But I'm not sure, as a purely scientific question, how even the best possible emissions scenario (zero anthropogenic emissions) could prevent an ever heating planet.

Help?!

(Folks in here may or may not know enough to provide the help I'm asking for. But maybe you know of folks who could?)

=============

Some recent news on Arctic sea ice and albedo:

Arctic thaw significantly worsens global warming risk

Excerpt:

Quote
"Melting ice is cooking the planet. Shrinking Arctic sea ice means the ocean is absorbing more energy from the sun, and it's now clear the effect is twice as big as thought – adding significantly to heating from greenhouse gases.

Arctic temperatures have risen 2 °C since the 1970s, leading to a 40 per cent dip in the minimum summer ice coverage in the Arctic Ocean. Open water soaks up more sunlight than ice, so as the ice retreats the ocean absorbs more energy, warming it and causing even more melting."
http://www.newscientist.com/article/dn25072-arctic-thaw-significantly-worsens-global-warming-risk.html#.UwU5VH3A-XM

« Last Edit: February 19, 2014, 03:17:27 PM by JRM »
My "avatar" graphic is Japanese calligraphy (shodō) forming the word shoshin, meaning "beginner's mind". --  http://en.wikipedia.org/wiki/Shoshin -- It is with shoshin that I am now and always "meeting my breath" for the first time. Try it!

Offline JRM

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Re: Climate Science Questions
« Reply #1 on: February 19, 2014, 03:26:37 PM »
A very strange statement on the 350.org website ...

Quote
"Right now we’re at 400 ppm, and we’re adding 2 ppm of carbon dioxide to the atmosphere every year. Unless we are able to rapidly turn that around and return to below 350 ppm this century, we risk triggering tipping points and irreversible impacts that could send climate change spinning truly beyond our control."
  (from http://350.org/about/science/)

How possibly could 350 ppm be reached "this century" -- even if we did EVERYTHING humanly possible, short of geoengineering? (And what sort of geoengineering methods could possibly work which would not also make matters worse?)

HELP?!

=========

Here's a recent PDF study report ...

What GHG Concentration Targets are Reachable in this Century?
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=9&cad=rja&ved=0CG0QFjAI&url=http%3A%2F%2Fglobalchange.mit.edu%2Ffiles%2Fdocument%2FMITJPSPGC_Rpt247.pdf&ei=eD8FU-r8C4yFogT9ioD4Bg&usg=AFQjCNE2ZmkB8im41RMpn6YXtm5GD4VcUw&sig2=t2oSmM5N5DHKK7H9pt20RA

I've only skimmed the summary so far, but the authors say the 350 ppm target is not reachable this century.
« Last Edit: February 19, 2014, 03:41:43 PM by JRM »
My "avatar" graphic is Japanese calligraphy (shodō) forming the word shoshin, meaning "beginner's mind". --  http://en.wikipedia.org/wiki/Shoshin -- It is with shoshin that I am now and always "meeting my breath" for the first time. Try it!

Offline JRM

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Re: Climate Science Questions
« Reply #2 on: February 19, 2014, 03:44:58 PM »
MKing,

I wanted to look at this as a scientific question. Your response does not seem to treat it as a scientific question. Do you not believe in science?
My "avatar" graphic is Japanese calligraphy (shodō) forming the word shoshin, meaning "beginner's mind". --  http://en.wikipedia.org/wiki/Shoshin -- It is with shoshin that I am now and always "meeting my breath" for the first time. Try it!

Offline Eddie

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Re: Climate Science Questions
« Reply #3 on: February 19, 2014, 04:04:14 PM »
Sometimes, when there looks like there is not an answer to the question, it is because…there isn't.

I was actually going to say the same thing. But from there I see it differently. I actually read something somewhere today that made me aware of yet another positive feedback loop I didn't know about ...that since the arctic ice is melting, the dark ocean absorbs a great deal more heat than the reflective ice it replaces, speeding up warming even more than previously thought.

I doubt anyone can reasonably estimate exactly how much we could influence the warming trend by say, cutting back to 20% of our current fossil fuel use, which could certainly be accomplished if there were any political will to make it happen, which there isn't.

As much as I dislike the people who post on McPherson's website, I like Guy's talks on climate change better than anyone's, and he paints a bleak picture, and his assessment seems perfectly reasonable as far as the science. I've read McKibben, and he's not much more optimistic either. You just have to decide who you're going to believe. I personally see no reason for them to be exaggerating. Where's the pay-off?

I watched this start to finish a few months ago. Have you seen it?

<a href="http://www.youtube.com/v/nEGlYXumguI&fs=1" target="_blank" class="new_win">http://www.youtube.com/v/nEGlYXumguI&fs=1</a>
« Last Edit: February 19, 2014, 04:52:15 PM by Eddie »
What makes the desert beautiful is that somewhere it hides a well.

Offline Eddie

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Re: Climate Science Questions
« Reply #4 on: February 19, 2014, 04:07:05 PM »
Not sure why that didn't embed.
www.youtube.com/watch?v=nEGlYXumguI
What makes the desert beautiful is that somewhere it hides a well.

Offline monsta666

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Re: Climate Science Questions
« Reply #5 on: February 19, 2014, 04:28:48 PM »
A very strange statement on the 350.org website ...

Quote
"Right now we’re at 400 ppm, and we’re adding 2 ppm of carbon dioxide to the atmosphere every year. Unless we are able to rapidly turn that around and return to below 350 ppm this century, we risk triggering tipping points and irreversible impacts that could send climate change spinning truly beyond our control."
  (from http://350.org/about/science/)

How possibly could 350 ppm be reached "this century" -- even if we did EVERYTHING humanly possible, short of geoengineering? (And what sort of geoengineering methods could possibly work which would not also make matters worse?)

HELP?!

I am no expert in climate change models but it would seem such a drastic change does not seem achievable if you take the stance that no man made measures i.e. geoengineering techniques will be implemented. If that course of action is ruled out then the only other means for atmospheric C02 concentrations to decline is if it is to occur naturally. Looking at historical records this process of diminishing C02 concentrations would take something in the order of 10,000 years.



However since concentrations are above historic highs of 300 ppm it is perhaps possible that the negative feedback loops maybe stronger thus inducing a faster decline in atmospheric concentrations of C02. Saying that is seems a very big stretch to assume the feedback loops would be stronger enough to generate such a dramatic decline over the next 86 years. In the end I don't think we should treat the sentence as a scientific statement. I believe it was written as a mere expression to highlight the problems of climate change i.e. we risk irreversible damage at 350 ppm but seeing as concentrations are at 400 ppm the risk of climate disaster grow higher by the day.

In the end it seems doubtful emissions will drop through intentional actions so as long as BAU exists we can expect C02 concentrations to increase. I doubt we will get some of the more dramatic increases as depicted on the graph below due to issues of peak oil and resource scarcity. However even accounting for the end of BAU scenarios I imagine C02 levels would still be too high particularly if you consider our capacity to deal with climate change would be greatly diminished due to a lack of fossil fuel energy, capital, money and debt (re)financing.


Online RE

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Re: Climate Science Questions
« Reply #6 on: February 19, 2014, 04:51:36 PM »

15 years as a geoscientist Energy Industry Shill in Career #2.

Fixed that for you.

RE
SAVE AS MANY AS YOU CAN

Online jdwheeler42

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Re: Climate Science Questions
« Reply #7 on: February 19, 2014, 05:51:11 PM »
How possibly could 350 ppm be reached "this century" -- even if we did EVERYTHING humanly possible, short of geoengineering? (And what sort of geoengineering methods could possibly work which would not also make matters worse?)
It'd be quite the challenge to find it again, but on a biochar list, there was an analysis that showed if we devoted 2% of world GDP to making biochar, within 50-75 years we would remove all the carbon dioxide released since the beginning of the industrial revolution.

And, if we decided this was a bad idea, we could just finish burning it again  :icon_sunny:

Online jdwheeler42

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Re: Climate Science Questions
« Reply #8 on: February 19, 2014, 06:00:12 PM »
Should this be expected to require centuries? And if so, what prevents global average temperatures from going up and up and up ... far beyond anything life as we know it can tolerate?

There appear to be more known positive feedback mechanisms than negative ones, with the known negatives being, apparently, much too weak to counteract the positives.
Ever been to the desert?  Overnight?  Outside?

Deserts may get really hot during the daytime, but they cool off really rapidly at night.

I think the big counterbalancing mechanism that most climate scientists are missing is desertification.  I think it can easily overwhelm any decreases in albedo in the Arctic and most other positive feedback mechanisms -- maybe not massive methane release, but that is self-limiting eventually.  Once the Great Plains, the Amazon, and the steppes of central Asia resemble the Sahara, I don't think global warming will be a problem anymore.

Oh yeah, and it will also help reduce the number of those pesky organisms causing all the problems, too....

Offline DoomerSupport

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Re: Climate Science Questions
« Reply #9 on: February 19, 2014, 06:03:32 PM »

As much as I dislike the people who post on McPherson's website, I like Guy's talks on climate change better than anyone's, and he paints a bleak picture, and his assessment seems perfectly reasonable as far as the science.

I believe he is knowingly promoting the worst-case scenario to get people to look at the data; when they do so they'll see the situation is bleak, but not as bad as he concluded. When I first met him, I asked what percentage of the climate data supported his extinction model.  He didn't hesitate to say, "5%".  He knows he's looking at outlier data.  I agree with his strategy, which is why I support him, despite not agreeing with his conclusions.

While looking for collaborating evidence, he does seem to miss a few minor factors.  For example, one factor he cites often is the start of flowers blooming in MA as though we had 2 degrees of warming, when the instruments say less than one.  Who do we trust, the instruments (and the people reading them) or the flowers?  I read the paper, and indeed, the flowers are blooming early.  The paper attributes it to the urban heat island effect, with data, and postulates that urban heat islands may give us an insight into how climate change in general will progress with regards to the impact on flowering plants.  The instruments within the "heat island" show the same change as the flowers.

The beufort gyre reversing and pulling warmer Atlantic waters into the Arctic?  It did reverse, for a few days, as a result of extreme storms.  Yet when I watch his video and recall his talk, the temporary nature of the phenomenon was not emphasized. 

It's the small things like that - a lot of them - that give me hope that it will be a bottleneck and not extinction.  Had it not been for the controversy surrounding NTHE, I would not have looked so closely at the data. 


Offline WHD

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Re: Climate Science Questions - MKing admits he is a shill...
« Reply #10 on: February 19, 2014, 09:48:05 PM »

15 years as a geoscientist Energy Industry Shill in Career #2.

Fixed that for you.

RE

So I've gone from energy reporter to energy industry shill! Movin' on up!! :emthup: :emthup:

Wait a minute... :icon_scratch:

Did MKing just admit, with pride, that he is an energy industry shill, for the money? For the money. Whatever the truth? Somebody take note please!  :kloguck:

WHD


Offline WHD

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Re: Climate Science Questions - MKing admits he is a shill...
« Reply #11 on: February 19, 2014, 10:17:48 PM »

15 years as a geoscientist Energy Industry Shill in Career #2.

Fixed that for you.

RE

So I've gone from energy reporter to energy industry shill! Movin' on up!! :emthup: :emthup:

Wait a minute... :icon_scratch:

Did MKing just admit, with pride, that he is an energy industry shill, for the money? For the money. Whatever the truth? Somebody take note please!  :kloguck:

WHD

My bad.

That was just RE, pointing out an inconvenient truth for MKing. LOL.

My sorries, MKing. You are so in love with the frackers and the drillers and the gougers, I got mixed up. No mistake though. :icon_mrgreen: LOL

WHD

Offline JRM

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Re: Climate Science Questions
« Reply #12 on: February 20, 2014, 10:05:17 AM »
I watched this start to finish a few months ago. Have you seen it?
<a href="http://www.youtube.com/v/nEGlYXumguI&fs=1" target="_blank" class="new_win">http://www.youtube.com/v/nEGlYXumguI&fs=1</a>

I've watched some of the McPherson videos... and read quite a few of his articles. To be honest, I have a severe allergy to McPherson. He is not always entirely honest. I've more than once discovered that he will present projected future "data" as if it were current fact, then extrapolate future scenarios on the basis of hypothesis as if the hypothetical "data" were fixed knowledge.  This is, rather obviously, among the poorest ways of presenting "science".  Whatever McPherson's agenda is, it isn't always a pursuit of knowledge, understanding or fact.

-------------- Edit -------------------------------------------

I said " ... he will present projected future "data" as if it were current fact, then extrapolate future scenarios ... "

Let me explain further. On one occasion I remember, McPherson selected his best guess from among multiple hypothetical future fossil fuel consumption scenarios (one at or near the BAU model), then slyly disguised the fact that he was making this selection choice while presenting the probable future result in global average temperature (and biological impact) terms. His projection was based on a projection, not on current data. And the article in question presented his hypothetical future scenario as if it were an unavoidable (though probabalistic) fact about the future. That's shoddy "science," and worse "journalism".
« Last Edit: February 20, 2014, 10:22:25 AM by JRM »
My "avatar" graphic is Japanese calligraphy (shodō) forming the word shoshin, meaning "beginner's mind". --  http://en.wikipedia.org/wiki/Shoshin -- It is with shoshin that I am now and always "meeting my breath" for the first time. Try it!

Offline JRM

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Re: Climate Science Questions
« Reply #13 on: February 20, 2014, 10:10:34 AM »
The beufort gyre reversing and pulling warmer Atlantic waters into the Arctic?  It did reverse, for a few days, as a result of extreme storms.  Yet when I watch his video and recall his talk, the temporary nature of the phenomenon was not emphasized. 

That's our Dr. McPherson, alright.
My "avatar" graphic is Japanese calligraphy (shodō) forming the word shoshin, meaning "beginner's mind". --  http://en.wikipedia.org/wiki/Shoshin -- It is with shoshin that I am now and always "meeting my breath" for the first time. Try it!

Offline DoomerSupport

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Re: Climate Science Questions
« Reply #14 on: February 20, 2014, 10:38:27 AM »
The beufort gyre reversing and pulling warmer Atlantic waters into the Arctic?  It did reverse, for a few days, as a result of extreme storms.  Yet when I watch his video and recall his talk, the temporary nature of the phenomenon was not emphasized. 

That's our Dr. McPherson, alright.

We know that how the data is presented will determine how people will react. I know some are concerned that the despondency and gloom, along with the cultish requirement that one must give up all hope before one is a "True NTHEer" may lead to a heaven's gate scenario. 

And the problem with that is....?

Most of us here believe there will be a global population reduction as a result of constraints we're facing.  Why would we discourage others from exiting the gene pool early?  It increases the chances for our tribes. 

Neither doing nothing, nor jumping on a passing comet, is a viable survival strategy.  Provided you can prevent them from taking you down with them, get out of the way. 

Guy is very smart.  He keeps the cultish aspect of NBLers at arms length and continues to post guest blogs which go against the prevailing paradigm there; if the NTHEers drink kool aid, it's not because he's leading them in that direction, he's simply presenting alternatives.  They choose their path.


 

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