Climate and Weather

Wez said:
Awesome, in one post you've managed to remind people of what the obvious is and at the same time, make a biblical assertion that despite, man's ability to affect the environment with it's activities, we cannot then control what those activities are.
But wait, are you saying that no matter what man does, we cannot have any affect on our Planet's environment?
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Butt weight?
Is that what you understood? "No matter what man does, we cannot have any affect on our planet's environment" Where did you read that?
My, my, my....
Obviously we influence our environment. We turn deserts into farming mecca's, see the Imperial Valley as an example.
We can't control climate cycles anymore than we can control sunspots or solar flares.
 
EvilGoalie 21 said:
Space is very cold and the Earth's interior is very hot. Against these extremes, it's amazing to me that the thin layer comprising the mantle, oceans and atmosphere acts as a buffer system that maintains a fairly narrow temperature range. There are forcings that perturb the system and processes that restore homeostasis. Carbon goes from being rock to gas and back again. Like you say, there are cycles, and they play out on different timescales. Here is a graph that shows an ~50 million year sequence during the Cretaceous when the planet appears to have burped out excess thermal energy in the form of intense sea floor spreading, what has been called a super-plume event. Outgassing of the newly formed rock is believed to have given rise to the dramatic greenhouse period commonly associated with the age of dinosaurs. The data depicted here is pure modeling from the 1990's based on the measured volume of seafloor produced and established rates of CO2 release but the overall picture is now supported with a finer granularity from isotope and ice core proxies. Of note, even with a crude treatment the initial ~10 million years of temp rise is sufficiently linear to calculate a tight slope; .000006 °C/year. Also, once the superplume event appears to have subsided, there were two ocean anoxic events that gave rise to hydrocarbon bearing "black shales". It's perhaps a bit ironic that our ability to work out the stratigraphy sequences in these sediments is based in large part on oil exploration. The corpses of all the little marine organism rained down to the bottom, dragging their carbon with them and forming sediments that removed the carbon from equilibrium with seawater. Carbon became rock, and these die offs are postulated to have allowed the oceans to once again act as a sink to absorb CO2 from the atmosphere, thereby returning global temperature back to the initial set point. At least that's the general theory.

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Its a good theory if cooling events were always gradual.
They are not.
 
EvilGoalie 21 said:
Now I can do what I wanted to do which is to plot these different time scale processes on a common x-axis from the same starting point, limiting the cretaceous data to the first 500,000 years. Green is 1880-present, blue is Milankovitch, brown is ocean volcanic forcing during the cretacous. For comparison, I placed a rough slope on the upswing of the Milankovitch cycle, which came out to .00006 °C/year. And I see I made a mistake in typing the Cretaceous slope, which should be .000002 °C/yr. The ratios of the Cretaceous and Milankovitch slopes compared to the slope for the 1880-present data are ~5000 and 165 respectively.

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So in saying that the ∆°C from 1880 on is not outside temp anomoly in the past, that's right. But what grabs attention is the ∆time during which the change has happened. Viewed on a geologic time scale, the impression is of a instantaneous oxidation reaction of fixed carbon back to gas (ie an explosion), accompanied by the expected temperature change. So the planet has mechanisms to buffer temperature, but they typically work on a very different timescale. How that plays out for the current forcing perturbing the system is of course the big question.
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There is no doubt volcanic activity affects climate. Catastrophic volcanic activity can have almost immediate effects worldwide. This is documented.
We also have a fairly uniform historic pattern of warming and cooling that doesnt always line up with volcanic events.
There are earth functions to temper climate that are still mysterious.
 
EvilGoalie 21 said:
Now I can do what I wanted to do which is to plot these different time scale processes on a common x-axis from the same starting point, limiting the cretaceous data to the first 500,000 years. Green is 1880-present, blue is Milankovitch, brown is ocean volcanic forcing during the cretacous. For comparison, I placed a rough slope on the upswing of the Milankovitch cycle, which came out to .00006 °C/year. And I see I made a mistake in typing the Cretaceous slope, which should be .000002 °C/yr. The ratios of the Cretaceous and Milankovitch slopes compared to the slope for the 1880-present data are ~5000 and 165 respectively.

View attachment 168

So in saying that the ∆°C from 1880 on is not outside temp anomoly in the past, that's right. But what grabs attention is the ∆time during which the change has happened. Viewed on a geologic time scale, the impression is of a instantaneous oxidation reaction of fixed carbon back to gas (ie an explosion), accompanied by the expected temperature change. So the planet has mechanisms to buffer temperature, but they typically work on a very different timescale. How that plays out for the current forcing perturbing the system is of course the big question.
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If you were to throw out a guess, given what information we can all pretty much agree on, where would we be within a natural cycle today?
Would we be at or near the top of a warming peak, cooling, or static?
Just looking at the most reliable temp records we have over the last 800,000 years, what pattern emerges, and where would we be without any AGW?
I know its a guess.
 
espola said:
-

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Here's the last 800,000 years. (allegedly)
Is there a pattern?
I see one, and I also see the peaks are steeper, and higher over the last 400,000 years or so.
Were c02 levels higher or lower during the last 400,000, or the preceding 400,000?
If the amazingly consistent pattern over the last 400,000 years continues, what should we expect?
 
Bernie Sanders said:
If you were to throw out a guess, given what information we can all pretty much agree on, where would we be within a natural cycle today?
Would we be at or near the top of a warming peak, cooling, or static?
Just looking at the most reliable temp records we have over the last 800,000 years, what pattern emerges, and where would we be without any AGW?
I know its a guess.
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Can look to see where we are on the eccentricity....CMIP5 will have the non-AGW projection. Will look for that later.
 
Wez said:
I see, you feel we are powerless to control a Climate cycle, so AGW/ACC isn't real. Makes Lion sense I guess...
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I see you believe we are powerful enough to control climate......optimistic and unrealistic all wrapped into one.
Perhaps you missed this? What does this tell you? Humans weren't around to effect the environment, the co2 levels were "pretty much where they are now", and it was even warmer.
"At the time of the mid-Pliocene Warm Period, average global temperatures were about 1 to 2 degrees Celsius higher than today, but concentrations of atmospheric carbon dioxide, at around 400 parts per million, were pretty much where they are now.

Tell us all again how we are gonna change the climate?
 
Bernie Sanders said:
If you were to throw out a guess, given what information we can all pretty much agree on, where would we be within a natural cycle today?
Would we be at or near the top of a warming peak, cooling, or static?
Just looking at the most reliable temp records we have over the last 800,000 years, what pattern emerges, and where would we be without any AGW?
I know its a guess.
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To my understanding, the main predictable drivers on that time scale are the Milanovich cycles. See attached for where we are regarding those cycles. There's a news/views part and then the paper from earlier this year. Mideval warm period appears to have been a road bump on a longer Milankovich-associated cooling trend that would normally lead to the close of the latest interglacial period. But it now appears the sufficiently high GHG concentrations (above ~240 ppm) can interfere with stabilizing the cooling trend. So we've given the next Ice Age the slip. Given the slow rate of CO2 removal from the atmosphere (absorption into oceans, photosynthesis, and rock weathering), the calculations suggest we may well miss the next one in ~100,000 years as well. During the mid-cretaceous warming period shown earlier, it appears the planet skipped hundreds of them.
 

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Bernie Sanders said:
Here's the last 800,000 years. (allegedly)
Is there a pattern?
I see one, and I also see the peaks are steeper, and higher over the last 400,000 years or so.
Were c02 levels higher or lower during the last 400,000, or the preceding 400,000?
If the amazingly consistent pattern over the last 400,000 years continues, what should we expect?
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The peaks you're referring to I interpret as the normal oscillation between interglacial periods due to the Milankovich cycles. The peaks come at ~100,000 intervals which is what is expected for the eccentricity periodicity and the wiggle and wobble tweak the interglacials and interact with other climatic processes so that each interglacial is not exactly the same. Regarding CO2 during the last 400,000, the green line on the graph (GHG forcing) is in essence showing that [CO2] normally tracks with these cycles but is now continuing at high. What they are normally linked is something I don't understand. My reading suggests that what we should expect is that the temp and CO2 components of these larger cycles are now being overridden by the anthropogenic components-hence continuing the current interglacial. Other than that depends on how warm its going to get and for how long. The changing of geologic epochs is frequently associated with major climatic periods that disrupt climate patterns tied to Earth's orbit. If we do start skipping oscillations, it's been suggested that we bring the Holocene to a close and start the Anthropocene.
 
Wez said:
Is it possible we are changing Climate?
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For me the answer is clearly yes. The questions are to what extent, how accurately can we anticipate outcomes, and what policies make the most sense. The medieval warming period, which increasingly appears to have been a mostly Northern hemisphere event is not well understood and there are lots of theories. One of the older ones actually is that large scale deforestation in Europe at that time was a trigger. I've read that there were areas of Europe that were actually more densely inhabited in the middle ages than they are now, which is something I would not have guessed. Anyway, once the Black Death arrived all the building came to a stop and nature resumed it's course towards a cooling climate.
 
EvilGoalie 21 said:
For me the answer is clearly yes. The questions are to what extent, how accurately can we anticipate outcomes, and what policies make the most sense. The medieval warming period, which increasingly appears to have been a mostly Northern hemisphere event is not well understood and there are lots of theories. One of the older ones actually is that large scale deforestation in Europe at that time was a trigger. I've read that there were areas of Europe that were actually more densely inhabited in the middle ages than they are now, which is something I would not have guessed. Anyway, once the Black Death arrived all the building came to a stop and nature resumed it's course towards a cooling climate.
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Exactly, why deniers spend so much energy railing against the possibility of AGW/ACC is a total mystery. Their politics have hijacked their ability to reason...
 
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