The IPCC 5th Assessment Report used a burning embers diagram to portray reasons for concern.
Ever golden. “You dolts, you’re not taking us seriously. It’s a catastrophe dammit. Here, we’ve included a picture of something on fire, does that help?”
I have a 97% Certainty that if there were no strong emergent negative feedbacks on climate That. We. Already. Would. Be. Frozen and/or Baked. To. Death. Already.
I got to wondering why the luminosity-temperature relationship on the Main Sequence of stars is a fat band rather than a thin curve.
It is inferred that over the 4.5 billion years of Solar System history, the Sun, a star on the Main Sequence, has increased some 20-30% in luminosity. The cause of this is that as hydrogen fuses into helium in the core, the core gets more compact and dense, increasing pressure and the rate of hydrogen fusion and making the Sun emit more energy.
I remember a talk at a dinner-lecture series at the U by someone in Climate Science relating what was then called Global Warming and being taken aside afterwards by one of the astronomy professors, telling me that the Earth’s climate has remained remarkably even over the billions of years even though the Sun is getting ever more hot. The hint was that there must be strong negative-feedback regulatory mechanisms in the Earth’s climate.
That said, the conventional thinking is that the atmosphere had a lot more CO2 in it in times past, and the warming Sun has been compensated by CO2 depletion, that is, until we came around to burn coal and oil and gas. Whether this is the case or this is more Narrative, I do not know, but I came across the Wikipedia page Timeline of the far future
Whereas the Sun has another 4-5 billion years to go before it starts migrating off the Main Sequence into its red giant phase, the claim is made that we really only have about half a billion years to go before the Sun’s brightening, still in the Main Sequence, ravages the Earth.
This is like the Dad Joke told by my father about how a freshman college student enrolled in Astronomy becomes anxious when the professor announces that the Sun will only support life on Earth for another 5 billion years. “5 billion years? Professor, you had me worried, I thought I heard you say 5 million years!”
If the world ends in 5 million years, or in 500 million years as claimed in Wikipedia is really not much of a human concern because not only ourselves but many generates of our progeny will be gone by the time that happens. But still, the 500 million year death sentence is short in time-to-go in terms of the history of life on Earth, it may speak to the Fermi Paradox and a Rare Earth with regard to the evolution of intelligent life — on other planets, life may have missed that 500 million year window, and so on.
Or how much of this is driven by Narrative that there are no effective self-regulatory mechanisms maintaining favorable temperature on the Earth in the presence of disturbances, natural or man-made?
The IPCC 5th Assessment Report used a burning embers diagram to portray reasons for concern.
Ever golden. “You dolts, you’re not taking us seriously. It’s a catastrophe dammit. Here, we’ve included a picture of something on fire, does that help?”
I have a 97% Certainty that if there were no strong emergent negative feedbacks on climate That. We. Already. Would. Be. Frozen and/or Baked. To. Death. Already.
I got to wondering why the luminosity-temperature relationship on the Main Sequence of stars is a fat band rather than a thin curve.
It is inferred that over the 4.5 billion years of Solar System history, the Sun, a star on the Main Sequence, has increased some 20-30% in luminosity. The cause of this is that as hydrogen fuses into helium in the core, the core gets more compact and dense, increasing pressure and the rate of hydrogen fusion and making the Sun emit more energy.
I remember a talk at a dinner-lecture series at the U by someone in Climate Science relating what was then called Global Warming and being taken aside afterwards by one of the astronomy professors, telling me that the Earth’s climate has remained remarkably even over the billions of years even though the Sun is getting ever more hot. The hint was that there must be strong negative-feedback regulatory mechanisms in the Earth’s climate.
That said, the conventional thinking is that the atmosphere had a lot more CO2 in it in times past, and the warming Sun has been compensated by CO2 depletion, that is, until we came around to burn coal and oil and gas. Whether this is the case or this is more Narrative, I do not know, but I came across the Wikipedia page Timeline of the far future
https://en.wikipedia.org/wiki/Timeline_of_the_far_future
Whereas the Sun has another 4-5 billion years to go before it starts migrating off the Main Sequence into its red giant phase, the claim is made that we really only have about half a billion years to go before the Sun’s brightening, still in the Main Sequence, ravages the Earth.
This is like the Dad Joke told by my father about how a freshman college student enrolled in Astronomy becomes anxious when the professor announces that the Sun will only support life on Earth for another 5 billion years. “5 billion years? Professor, you had me worried, I thought I heard you say 5 million years!”
If the world ends in 5 million years, or in 500 million years as claimed in Wikipedia is really not much of a human concern because not only ourselves but many generates of our progeny will be gone by the time that happens. But still, the 500 million year death sentence is short in time-to-go in terms of the history of life on Earth, it may speak to the Fermi Paradox and a Rare Earth with regard to the evolution of intelligent life — on other planets, life may have missed that 500 million year window, and so on.
Or how much of this is driven by Narrative that there are no effective self-regulatory mechanisms maintaining favorable temperature on the Earth in the presence of disturbances, natural or man-made?