On Tue, Oct 17, 2017 at 08:57:28PM -0400, John Newman wrote:
On Oct 17, 2017, at 7:59 PM, Zenaan Harkness <zen@freedbms.net> wrote:
On Tue, Oct 17, 2017 at 05:13:57PM -0400, John Newman wrote:
On Oct 17, 2017, at 4:39 PM, John Newman <jnn@synfin.org> wrote:
On Tue, Oct 17, 2017 at 10:02:45AM +1100, Zenaan Harkness wrote: > On Mon, Oct 16, 2017 at 12:53:56PM -0400, Ric Moore wrote: > On 10/15/2017 10:50 PM, Zenaan Harkness wrote:
> This is one of the best put together summaries of the ???Global > Warming??? (originally global cooling, now PC "climate change") debate > I've ever seen:
Damn! Even I understood that!! Thanks! Ric
Here's an even easier one - see the picture on page 8 (another little doc put together by Gil May) - 4 pine trees grown in controlled conditions with varying CO2 levels.
Plants really needed the CO2 from the industrial revolution - otherwise the levels were quite literally precariously low for life on this planet. I'd like to see how long we'll be "right" for going forward with the amount of plant food we've pumped into our atmosphere. At least we're nearly out of the red zone...
Who the fuck is Gil May?
You are the most gullible idiot I've ever... wait, actually, you're quite representative of a bunch of gullible fucking morons that seem to dominate humanity.
Such subtlety. Such succinctity. Such grace and humility - I'm the humble one around here, and don't you forget it‼
Link: https://climate.nasa.gov/climate_resources/24/
See attached graph. <24_co2-graph-021116-768px.jpg>
in case the significance doesn't dawn - look at the time scale.
Thanks for your graph.
YW
Sorry for the docx file - I guess you were unable to open that first one properly, I've saved it as PDF (attached) - check out the graph on page 10, and note its timescale - it's another time scale again.
Yes I didn’t read that far into your crap.. however, it doesn’t mean what you think it means. Things aren’t as simple as your holocaust denying mind would have them be. Open your mind! ;)
Link - load it for the graphs:
https://www.skepticalscience.com/co2-higher-in-past-intermediate.htm
Tnx.
Over the Earth's history, there are times where atmospheric CO2 is higher than current levels. Intriguingly, the planet experienced widespread regions of glaciation during some of those periods. Does this contradict the warming effect of CO2? No, for one simple reason. CO2 is not the only driver of climate. To understand past climate, we need to include other forcings that drive climate. To do this, one study pieced together 490 proxy records to reconstruct CO2 levels over the last 540 million years (Royer 2006). This period is known as the Phanerozoic eon.
I notice you keep using these words suggesting causation - "driver", "forcing". I believe there is scientific 'dispute' (alternative theories) as to which factors are the cause/driver(s) and which are the result/effect - the classic scientific theory being that sun output, primarily or exclusively, is the absolute dominant driver of weather, temperature, and, 'consequently', CO2.
Atmospheric CO2 levels have reached spectacular values in the deep past, possibly topping over 5000 ppm in the late Ordovician around 440 million years ago.
And that was apparently only good for life on this planet.
However, solar activity also falls as you go further back. In the early Phanerozoic, solar output was about 4% less than current levels. The combined net effect from CO2 and solar variations are shown in Figure 2. Periods of geographically widespread ice are indicated by shaded areas.
This is new data for me. Thanks again. "Dude, like, what's a 4% drop in solar output between friendly planets anyway?" "Glaciation, dude, and the end of life as we know it." "It's life, Jim, but not as we know it, not as we know it."
Figure 2: Combined radiative forcing from CO2 and sun through the Phanerozoic. Values are expressed relative to pre-industrial conditions (CO2 = 280 ppm; solar luminosity = 342 W/m2). The dark shaded bands correspond to periods with strong evidence for geographically widespread ice.
Aaand ... we should be trying to avoid those¿
Periods of low CO2 coincide with periods of geographically widespread ice
Mm hm! Got that‼ And "current" (for "on a scale of a billion years" values of "current") atmospheric CO2 levels are crazy low! BUT (say some other data), our Sun's output is 4% higher than at those times, so we're cool! I mean hot/good/ok…
(with one notable exception, discussed below). This leads to the concept of the CO2-ice threshold - the CO2 level required to initiate a glaciation. When the sun is less active, the CO2-ice threshold is much higher. For example, while the CO2-ice threshold for present-day Earth is estimated to be 500 ppm, the equivalent threshold during the Late Ordovician (450 million years ago) is 3000 ppm.
This is essentially what I've been comprehending - the ONLY significant potential problem for life on this planet, is CO2 levels dropping below "glaciation might happen" levels (which level varies according to Sun output, which makes perfect sense). So let's increase atmospheric CO2 levels if they're "currently" low...
However, until recently, CO2 levels during the late Ordovician were
Damn, you do seem to know your climate science termifrogology.
thought to be much greater than 3000 ppm which was problematic as the Earth experienced glacial conditions at this time. The CO2 data covering the late Ordovician is sparse with one data point in the CO2 proxy record close to this period - it has a value of 5600 ppm. Given that solar output was around 4% lower than current levels, CO2 would need to fall to 3000 ppm to permit glacial conditions. Could CO2 levels have fallen this far? Given the low temporal resolution of the CO2 record, the data was not conclusive.
Precisely stated. Very good.
Research examining strontium isotopes in the sediment record shed more light on this question (Young 2009). Rock weathering removes CO2 from the atmosphere. The process also produces a particular isotope of strontium, washed down to the oceans via rivers. The ratio of strontium isotopes in sediment layers can be used to construct a proxy record of continental weathering activity. The strontium record shows that around the middle Ordovician, weatherability increased leading to an increased consumption of CO2. However, this was balanced by increased volcanic outgassing adding CO2 to the atmosphere. Around 446 million years ago, volcanic activity dropped while rock weathering remained high. This caused CO2 levels to fall below 3000 ppm, initiating cooling.
THAT is significant! Not only did atmospheric CO2 drop to levels (given Sun output at that time) which could "permit" glaciation - glaciation in fact occurred. Bad for life on this planet of course...
It turns out falling CO2 levels was the cause
"in combination with then-Solar output levels"
of late Ordovician glaciation.
So yes in the past, CO2 levels were a good --order of magnitude-- higher than we see today, and with average sun output "just" 4% lower, even 3000ppm was not enough to stop glaciation - the end of the yummy sunny planet we know today, for a few (tens?) of millions of years at a time...
So we see that comparisons of present day climate to periods 500 million years ago need to take into account that the sun was less active than now.
Sure. Both interesting and useful to comprehending our current world - your “value equation” is improving, John :) Keep this up and you'll soon join the illustrious ranks of those pointing out there's a slight difference between rickety wooden fence pailing gates and multi-hinged cam-locking steel doors with industrial gas seals, and which ones -were- at Auschwitz, and which ones -were not-.
What about times closer to home? The last time CO2 was similar to current levels was around 3 million years ago, during the Pliocene. Back then, CO2 levels remained at around 365 to 410 ppm for thousands of years. Arctic temperatures were 11 to 16°C warmer (Csank 2011). Global temperatures over this period is estimated to be 3 to 4°C warmer than pre-industrial temperatures. Sea levels were around 25 metres higher than current sea level (Dwyer 2008).
Noah's "flood" perhaps? Different timing it seems, but who knows...
If climate scientists were claiming CO2 was the only driver of climate, then high CO2 during glacial periods would be problematic. But any climate scientist will tell you CO2 is not the only driver of climate. Climatologist Dana Royer says it best: "the geologic record contains a treasure trove of 'alternative Earths' that allow scientists to study how the various components of the Earth system respond to a range of climatic forcings."
The solution to different "scientific models" or theories suggesting different outcomes, different causation/drivers? More science.
Past periods of higher CO2 do not contradict the notion that CO2 warms global temperatures.
Ack.
On the contrary, they confirm the close coupling between CO2 and climate.
Ack. But John, putting those two sentences right next to each, though accurate, may mislead someone not so well trained in the art of clear thinking as you appear to be. Point being: "close coupling of A,B" != "A causation -> B", instead it might mean "B causing -> A" just that we can't yet conclusively determine which way it actually is. So: - we need CO2 levels to get up to "reasonable levels" - to ensure a nice warm and wet greenhouse planet - a planet which is not about to slip into glaciation - which glaciation would be an ELE for most species on this planet. - Lower Sun output levels are greatly concerning, - especially when atmostpheric CO2 levels are below the "ratio" (if we can have any accuracy about the relative numbers) - But this of course still rests on the assumption that CO2 levels are a driver of global average temparature, rather than the result - CO2 levels "too low" do signify the possibility of imminent glaciation - but thankfully, CO2 levels are currently increasing sharply, so we should be “right for now”. Yay! It may be that: - Solar output is the ultimate driver of atmospheric CO2. - In fact it's hard to imagine otherwise... - But we're not completely sure. But we are sure that abundant atmospheric CO2 correlates to abundant life on this planet, and the key potential problem is glaciation, which correlates with abundant ice on this planet and not much life. and so from this foundation, rapidly increasing atmospheric CO2 levels is a very good sign indeed (given current historically low levels). It seems. It's a very intersting discussion, thanks for such a detailed response :) Z