Heating up down under

[sjastro]

Potential theory mentioned in my previous post is a branch of applied mathematics and is used by many of the sciences.

Field of Science or Study	Theory or Concept	Description / Principle (Energy Landscape Perspective)
Physics	Gravitational Potential Energy Landscape	Describes how mass distributions create valleys (stable states) and peaks (unstable points) in gravitational potential; objects move toward minima of potential energy.
Quantum Mechanics	Quantum Potential Wells and Energy Landscapes	Particles occupy quantized energy states within potential wells; transitions occur when sufficient energy allows crossing to higher or adjacent wells.
Thermodynamics	Free Energy Landscapes (Gibbs or Helmholtz)	Systems evolve toward configurations of minimum free energy; metastable and stable states correspond to local minima on the energy surface.
Climate Science	Climate Energy Landscape Model	The Earth’s climate can be represented as an energy landscape with multiple potential wells (stable climate states) separated by barriers (tipping thresholds); feedbacks shape the surface.
Geophysics	Tectonic and Gravitational Energy Landscapes	Earth’s crust and mantle evolve through potential minima defined by gravitational and elastic energy; transitions occur during earthquakes or mantle convection.
Oceanography	Potential Energy Surfaces and Circulation Stability	Oceanic masses move along gradients in gravitational and density-derived potential energy; multiple equilibrium states can exist in thermohaline circulation.
Astrophysics	Stellar and Planetary Stability Landscapes	Stars and planetary systems evolve within combined gravitational and thermal energy landscapes; collapse, ignition, or equilibrium correspond to different minima.
Chemistry	Reaction Energy Landscapes	Chemical reactions proceed along potential energy surfaces with reactants and products at minima, and activation barriers representing transition states.
Biophysics	Protein Folding Energy Landscape	Proteins explore a rugged energy landscape; folded structures correspond to global or local minima of potential energy.
Ecology	Ecological Stability Landscapes	Ecosystem states are modeled as basins of attraction in an energy landscape; disturbances can push systems over thresholds into alternate stable states.
Economics (Complex Systems)	Energy-Like Potential Landscape Models	Economic and social systems are sometimes represented as energy landscapes where equilibria correspond to minima and shifts occur when barriers are crossed.
Mathematical Modeling	Nonlinear Dynamical Potential Landscapes	Uses scalar potential functions to visualize how systems move between attractors; stable equilibria correspond to minima, unstable equilibria to maxima.

This AI compiled list ignored one of the more profound examples of potential theory, the birth of the universe according to the Hot Big Bang theory.

what is the evidence that universe is 13.7B years old?

I have a question about your post. We are speaking of the "beginning of our universe - specifically the "Big Bang Theory". My expertise ends at The Big Bang Theory being one of my favorite shows, so forgive me if my question seems silly. @PeterDona mentioned the law of thermodynamics (I...

www.christianforums.com

 

[eclipsenow]

Eclipsenow:

That particular discussion was on the subject of equilibriums. The only way it intersects a discussion of AGW is whether AGW could form a new equilibrium. I'll point out outliers, hyperbole, and outright panic, but won't claim that AGW is or isn't happening. The issue here is equilibriums, which, from what little is understood about climate, I don't think really exist.

But they do. We've been in one - roughly - for a few million years.

TIME IS RELATIVE
I hear your point. Over the long haul, the climate looks very chaotic. But can you hear our point? That in the short term - say the last 2 or 3 million years of relatively stable climate with Milankovitch cycles driving the ice ages - it has not been this hot?

But again - I really hear you! Over the long haul - agriculture has only been around 10,000 years or so ago, and larger civilisations with writing maybe 6 or 7,000 years? That's a blink in climate terms. But very important in ours!

If you stretch things out to 10's or 100's of millions of years, of course the climate looks more chaotic. But as we said, some of the much earlier and larger climate forcings pushing the earth into a number of super-hot-house phases are over. The earth is cooler. There's just not as much volcanism now. That particular CO2 forcing is less sensitive. It might flare up again - if certain magma spots get active. Of course - if it flares up TOO suddenly like Yellowstone super-volcano BLOWING - that of course chucks sulphur into the atmosphere and freezes the place again!

Yet in that long term climate trend - remember the sun is 2% hotter - making each gram of CO2 more dangerous than back in the age of Monsters. (Pre-dinosaurs.)

ALSO NOTE - most of the previous GLOBAL EXTINCTION LEVEL EVENTS were to do with climate change! Oceans became anoxic and died, land biodiversity suffered, and for a variety of reasons the super-hot-house earth's (each almost like different planets given the time and continental drift between each phase) had a really bad track record as far as life is concerned.

Back to the point. We've been stable for 3 million years. But now we're breaking it!

 

[Tuur]

But they do. We've been in one - roughly - for a few million years.

A few million? Uh-uh. Three hundred years ago, we were still in the Little Ice Age. The Medieval Warm Period ended not even 800 years ago. The last glacier maximum was only about 26,000 years ago. About 12,000 years ago, the Sahara had forests and grasslands. During the last glacier maximum, there were sand dunes in parts of what's now the Southeastern US. Some are still existent. Bluegrass, in North America associated with the latitude of Kentucky, was found hundreds of miles further south.

Much more recently, the coast of the state of Georgia was hammered by hurricanes in the 19th Century, but not in the 20th. My father remembers a period of time warm enough that he saw no point in springing for a heater for his first vehicle (heaters were optional then). Lupine had become a cover crop so common that part of the US was dubbed the Lupin Belt. Then the winters turned colder, with back to back cold winters all but wiping out the lupin seed stock and farmers used more chemical fertilizers to take up the slack. In my lifetime, anything more than a dusting of snow locally was practically unheard of, but in the last half of my life there have been more measurable accumulations of snow.

Equilibrium? Not hardly.

 

[eclipsenow]

A few million? Uh-uh.

If you read in context - you'll note that I included the Milankovitch cycles as part of this 'stable' climate. In other words - from the BIG Paleoclimate picture I'm talking about the MEGA-SWINGS of the deep past. Swings that look like different planets out of Star Wars - about 600 million years ago looking like Hoth, to other periods that look more like Tatooine or Dune!
Swings from our Pre-industrial average global temperature of 13.7 degrees C up to over 30 degrees C!
(Graph from Forbes!)

If you look across to the right - you'll see us at the end of the Cenozoic which covers the period from the Dinosaur Killer 66 million years ago to now. See how much cooler we are? 13.7 degrees before the Industrial Revolution.

Compared to THAT the Milankovitch cycles of the past 3 million years are stable, staying at roughly our 13.7 degrees but DROPPING down to maybe -5 or 6 off that mean. (Graph from Real Climate) So oscillating from "nice" down to "Half Hoth" - but never "Hoth" to "Tatooine."

...the Little Ice Age... The Medieval Warm Period...

Soz - but I'm going to have to stop you there. The MWP was a local event, not a global event.
Even the Little Ice age was mainly a local effect with a tiny global effect.
Zoomed out to the 3 million year period graph I showed above - this period would almost look like a straight line - except for the end. (Which tells you what we are doing.)

​

The Medieval Warm Period (MWP), also known as the Medieval Climate Optimum or the Medieval Climatic Anomaly, was a time of warm climate in the North Atlantic region that lasted from about 950 CE to about 1250 CE.[2] Climate proxy records show peak warmth occurred at different times for different regions, which indicate that the MWP was not a globally uniform event.[3] Some refer to the MWP as the Medieval Climatic Anomaly to emphasize that climatic effects other than temperature were also important.[4][5]​

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The MWP was followed by a regionally cooler period in the North Atlantic and elsewhere, which is sometimes called the Little Ice Age (LIA).​

​

Possible causes of the MWP include increased solar activity, decreased volcanic activity, and changes in ocean circulation.[6] Modelling evidence has shown that natural variability is insufficient on its own to explain the MWP and that an external forcing had to be one of the causes.[7]​

Medieval Warm Period - Wikipedia

en.wikipedia.org

The last glacier maximum was only about 26,000 years ago. About 12,000 years ago, the Sahara had forests and grasslands.

I would love to have some sort of invisible time-machine drone I could fly back and see those periods!

My father remembers a period of time warm enough that he saw no point in springing for a heater for his first vehicle... Equilibrium? Not hardly.

Yeah - all those anecdotes are so powerful!
"Me gramps gramps gramps was a Viking who grew wine up in Greenland..." or whatever.

But I'll repeat it. These were local effects, relative equilibrium compared to the larger Ice Age cycles of the last 3 million years - and NOTHING on the cataclysmic HOTH to TATOOINE changes of those ancient periods!

So if the MWP can bless some Europeans on one hand, and then the Little Ice Age curse them on another - and these are LOCAL climate effects - are you beginning to get just a taste of the power of extra heat energy accumulating in the wrong places?

Now imagine the entire planet cooking up an extra 2 or 3 degrees!​

 

[sjastro]

Here are Earth's temperatures changes over the last 500 million years.

​

Here is a table of the major warming/cooling events over this period where the trigger points have been met and its consequences as the Earth has settled into a more stable equilibrium.

Major Temperature Changes and Trigger Points in Earth’s Last 500 Million Years (with AGW Predictions)​

Geological Event / Period	Approx. Time (MYA)	Temperature Change (°C)	Duration (kyr or Myr)	Rate of Change	Trend	Trigger Point & Consequences
Late Ordovician Glaciation	445	−5–10°C	~1 Myr	−5–10°C/Myr	Cooling	Trigger: Atmospheric CO₂ fell below ~3000 ppm due to silicate weathering. Consequence: Rapid ice-sheet expansion, global glaciation, marine extinction (~85%).
Late Devonian Warming–Cooling Cycles	380–360	±4°C	~5 Myr	±0.8°C/Myr	Oscillating	Trigger: Expansion of terrestrial plants enhanced weathering, altering CO₂ and nutrient cycles. Consequence: Ocean anoxia; collapse of reef ecosystems; biotic turnover.
End-Permian (P–T Boundary) Warming	252	+8–10°C	~60 kyr	+0.13°C/kyr	Rapid warming	Trigger: Siberian Traps CO₂ and methane release exceeded carbon-sink capacity. Consequence: Ocean acidification, anoxia, 90% species extinction (“Great Dying”).
End-Triassic Warming	201	+4–6°C	~100 kyr	+0.05°C/kyr	Warming	Trigger: CO₂ surge from Central Atlantic Magmatic Province volcanism. Consequence: Mass extinction (~80% species), ocean acidification, ecological reset.
Early Jurassic Cooling (Toarcian Event)	183	−3–4°C	~500 kyr	−0.006°C/kyr	Cooling	Trigger: Organic carbon burial drew down atmospheric CO₂. Consequence: Ocean oxygenation recovery, temporary biotic recovery.
Mid-Cretaceous Hothouse	100–90	+4–6°C	~10 Myr	+0.5°C/Myr	Warming	Trigger: Sustained volcanism, elevated CO₂ (>1000 ppm). Consequence: Polar warmth, sea level +200 m, low equator-to-pole gradient, low oxygen oceans.
Cretaceous–Paleogene (K–Pg) Cooling	66	−5°C	~100 kyr	−0.05°C/kyr	Cooling	Trigger: Chicxulub impact and sulfate aerosols blocked sunlight. Consequence: Collapse of food webs, non-avian dinosaur extinction, mammal radiation.
Paleocene–Eocene Thermal Maximum (PETM)	56	+5–8°C	~20 kyr	+0.25–0.4°C/kyr	Rapid warming	Trigger: Abrupt methane hydrate and CO₂ release. Consequence: Ocean acidification, mammal dwarfing, poleward species migration.
Eocene–Oligocene Cooling (Antarctic Glaciation)	34	−4°C	~400 kyr	−0.01°C/kyr	Cooling	Trigger: CO₂ dropped below ~600 ppm — threshold for Antarctic ice-sheet formation. Consequence: Permanent glaciation of Antarctica; new albedo–CO₂ feedback regime.
Middle Miocene Climatic Transition	14	−2–3°C	~2 Myr	−1.0°C/Myr	Cooling	Trigger: CO₂ fell to ~300 ppm; Antarctic ice expanded; thermohaline circulation shift. Consequence: Strengthened polar fronts; modern cold deep oceans established.
Pliocene Warm Period	3	+2–3°C (above preindustrial)	~200 kyr	+0.01°C/kyr	Warming	Trigger: CO₂ stabilized near 400 ppm. Consequence: Sea level +10–20 m; reduced polar ice, similar to near-future projections.
Pleistocene Glacial–Interglacial Cycles	2.6–0.011	±5–6°C	~100 kyr/cycle	±0.05°C/kyr	Oscillating	Trigger: Orbital (Milankovitch) thresholds altering ice-albedo feedbacks. Consequence: Regular glacial cycles; global ecosystems adapted to 100 kyr rhythm.
Last Glacial Maximum → Holocene Warming	20–11.7 kyr ago	+5°C	~8 kyr	+0.6°C/kyr	Warming	Trigger: Rising insolation, ice–albedo feedbacks, CO₂ rise from 180→280 ppm. Consequence: Ice retreat; stable Holocene climate; rise of agriculture and civilization.
Industrial–Anthropocene Warming (AGW)	0.000185–0	+1.3°C (so far)	~170 yr	+7.6°C/kyr	Rapid warming	Predicted Triggers: Approaching multiple tipping thresholds — • Greenland ice-sheet melt accelerating (>1.5°C global mean) • West Antarctic collapse (~2°C) • AMOC weakening (~2–4°C) • Permafrost carbon release (~1.5–2°C) • Coral reef collapse (~1.5°C). Predicted Consequences: Amplified feedbacks, abrupt sea-level rise (>1 m/century possible), ocean acidification, biosphere restructuring, irreversible warming trajectory if CO₂ >500 ppm.

While there have been considerable temperature changes compared to AGW, the warming/cooling rate is markedly less than AGW.

 

[Tuur]

If you read in context -

If you'll consult your dictionary, you'll find "equilibrium" doesn't mean what you seem to think it means.

 

[Stopped_lurking]

If you'll consult your dictionary, you'll find "equilibrium" doesn't mean what you seem to think it means.

Isn't this just a question of talking about equilibrium on differing timescales. On average the power we get from the sun must be the same (or very very very close to) as we radiate back into space. Otherwise we would be burnt to a crisp or an ice ball. This is beside AGW. That there is some shorter timescale dynamics in the system doesn't negate that.

 

[Tuur]

But I'll repeat it. These were local effects, relative equilibrium compared to the larger Ice Age cycles of the last 3 million years - and NOTHING on the cataclysmic HOTH to TATOOINE changes of those ancient periods!

No. The back-to-back cold winters that all but knocked out lupin seed stock happened outside of a locality. It fundamentally changed farming in the Southeastern US. Lupin fixes nitrogen and, unlike velvet bean (a popular winter cover crop prior to lupin) breaks down easily and doesn't drag on plows. Before that event, winters were warmer in living memory.

You say it's "anecdotal." I say it's "inconvenient." It's easy to imagine a Medieval professor dismissing the discrepancy Galan's work on anatomy and what a student sees as "anecdotal."

Yet here is a curious thing: My account of cold temperatures that wiped out lupin stock after a series of warmer winters is deemed local and anecdotal. Yet the current temperature in parts of Australia this October is treated as harbingers of doom. If you're willing to dismiss those cold winters as local and anecdotal, then we should do the same with this October's temperatures in Australia.

Your call.

 

[Tuur]

Isn't this just a question of talking about equilibrium on differing timescales. On average the power we get from the sun must be the same (or very very very close to) as we radiate back into space. Otherwise we would be burnt to a crisp or an ice ball. This is beside AGW. That there is some shorter timescale dynamics in the system doesn't negate that.

The output change is in the range of tenths of a percent., maybe closer to around 1 tenth of a percent. The point is it isn't steady, and, as the hydrogen depletes will slowly grow hotter over just a few billion years before it becomes a red giant. At least, that's the current forecast, and no, that's not a joke.

My point in mentioning that is that it's not stable output. Someone with a keen eye might notice a difference in brightness of those old incandescent bulbs as voltage fluctuates within accepted levels. It's a slight change, but still a change. Even a slight change in solar output affects the energy a planet receives from the sun. It may be in the range of tenths of a percent, but it's still a change. It's not equilibrium.

 

[Stopped_lurking]

The output change is in the range of tenths of a percent., maybe closer to around 1 tenth of a percent. The point is it isn't steady, and, as the hydrogen depletes will slowly grow hotter over just a few billion years before it becomes a red giant. At least, that's the current forecast, and no, that's not a joke.

My point in mentioning that is that it's not stable output. Someone with a keen eye might notice a difference in brightness of those old incandescent bulbs as voltage fluctuates within accepted levels. It's a slight change, but still a change. Even a slight change in solar output affects the energy a planet receives from the sun. It may be in the range of tenths of a percent, but it's still a change. It's not equilibrium.

But the Earths energy input and output are in equilibrium? I know you work(ed?) with electrics, its like Kirchoffs circuit laws they are true for normal time- and length scales and a statistically high number of charge bearing particles (or electromagnetic waves if you prefer that representation) but but they are not true at all time- and length scales and when very few charge bearing particles are involved.

I know that the Sun's output changes, but the whether or not the Earth's energy exchange can best be described as being in equilibirum depends on what timescale is used.

 

[sjastro]

The output change is in the range of tenths of a percent., maybe closer to around 1 tenth of a percent. The point is it isn't steady, and, as the hydrogen depletes will slowly grow hotter over just a few billion years before it becomes a red giant. At least, that's the current forecast, and no, that's not a joke.

My point in mentioning that is that it's not stable output. Someone with a keen eye might notice a difference in brightness of those old incandescent bulbs as voltage fluctuates within accepted levels. It's a slight change, but still a change. Even a slight change in solar output affects the energy a planet receives from the sun. It may be in the range of tenths of a percent, but it's still a change. It's not equilibrium.

Lets use the Tacoma bridge collapse as an analogy. The bridge represents the Earth and wind is the solar radiation reaching the Earth.
This is what happens when the bridge is in an unstable equilibrium.

​

Being a suspension bridge it was designed to be flexible and undergo slight movements to absorb and dissipate wind energy.
In this state the bridge was in a stable equilibrium where the bridge would react to varying winds speeds.
Unfortunately when the wind velocity reached 35 miles per hour it caused the bridge to vibrate at its resonance frequency creating an unstable equilibrium where movements in the bridge where amplified and the trigger point was reached when the bridge collapsed.
A new more stable equilibrium is what remains of the bridge.

One point of the analogy is when the wind speed was below 35 miles per hour the bridge reacted to different speeds but was still in a stable equilibrium.
Likewise if there was no AGW, the Earth would remain in a stable equilibrium even if the solar output varied slightly since the energy radiated back into space in the form of electromagnetic radiation would also change to the same degree as the solar output.

 

[eclipsenow]

No.

Yes, because other proxies around the planet do not show the same temperature trends!

I know it's inconvenient to your narrative, but it's the facts. Because, science.

Because me Gramps Gramps Gramps doesn't really cut it when scientists out in the field go looking for a mediaeval warm period or little ice age in Australia or New Zealand or South America somewhere or Africa somewhere and just can't find it.

Also if you actually think there was an extended global mediaeval warm period and little ice age, what were the causal mechanisms?

It's not just a matter of narratives. It's a matter of analysing the various natural forcings involved, how large they were, and what evidence there is for them around the entire planet.

Read the wiki and the source documents and the IPCC material on all of this.

Or you can go back to stories about me Gramps Gramps Gramps but I'm not really going to listen.

 

[eclipsenow]

The output change is in the range of tenths of a percent., maybe closer to around 1 tenth of a percent. The point is it isn't steady, and, as the hydrogen depletes will slowly grow hotter over just a few billion years before it becomes a red giant. At least, that's the current forecast, and no, that's not a joke.

My point in mentioning that is that it's not stable output. Someone with a keen eye might notice a difference in brightness of those old incandescent bulbs as voltage fluctuates within accepted levels. It's a slight change, but still a change. Even a slight change in solar output affects the energy a planet receives from the sun. It may be in the range of tenths of a percent, but it's still a change. It's not equilibrium.

But scientists have studied the sun? They understand the variations and they just do not account for the amount of warming the earth has experienced. That extra heat energy has to come from somewhere, right?

Check the IPCC on it. They've accounted for every forcing we know of. Analyzed, dissected, meditated on it even.

Joseph Fourier calculated how much warmer the earth was than the moon because of our atmosphere - about 200 years ago. Then Eunice Foote did her experiments with thermometers in 1856. Equal glass jars with the different gases in the same sun, and demonstrated that CO2 was a powerful greenhouse gas.

It's 127 years since Nobel Prize winner Svante Arrhenius developed the world's first model of what doubling CO2 would do to the earth's temperature.

The physics of CO2 was established old science when our grandparents were in kindergarten.