Very long-term temperature trend

[DOGE3500]

[mentors' note: this thread was spun off from https://www.physicsforums.com/threads/what-papers-is-the-co2-climate-change-theory-based-on.1081649/. Participants are reminded to review the sticky policy thread at the top of this subforum]

“Science” tells us we are currently in the coldest period since the last 485 million years.

 

[Nugatory]

we are currently in the coldest period since the last 485 million years.

The rate of change is also important.

 

[Ken Fabian]

[mentors' note: this thread was spun off from https://www.physicsforums.com/threads/what-papers-is-the-co2-climate-change-theory-based-on.1081649/. Participants are reminded to review the sticky policy thread at the top of this subforum]

“Science” tells us we are currently in the coldest period since the last 485 million years.

Going by climate 'periods' perhaps it is 'coldest period'. But for most of the time homo sapiens has existed as a species it was significantly colder than now - colder than anything in the last 10,000 year of the relatively warm and unusually stable pre-industrial late Holocene, an interglacial period.

Even before the anthropogenic warming spike it was not the coldest - hardly any ice sheets at all, just another 70m of sea level worth left locked up as ice. If ever there were a 'best' climate for humans it is hard to go past the Holocene.

Is there something about that long temperature series and the study it comes from that you want to discuss?

 

[Ken Fabian]

The full study is here -​

A 485-million-year history of Earth’s surface temperature​

The abiding relationship between CO2 and global temperatures is written clearly in that history. That history (PhanDA) is testament to how hot it gets when carbon gets carried away with oxygen.

From the abstract -

There is a strong relationship between PhanDA GMST and CO2, indicating that CO2 is the dominant control on Phanerozoic climate.

Worse news is the strength of that connection looks very strong, more in line with - actually well beyond - James Hansen's more paleo-climate based estimations of climate sensitivity (the 'alarmist's' estimate) than estimates based on climate modeling.

The GMST-CO2 relationship indicates a notably constant “apparent” Earth system sensitivity (i.e., the temperature response to a doubling of CO2, including fast and slow feedbacks) of ∼8°C, with no detectable dependence on whether the climate is warm or cold.

Confirmed climate sensitivity of ~8C would mean we are seriously underestimating the severity of the current climate change problem - that all we hold dear is in deep, deep trouble, already.

Let us hold hard to hope that what the models and best estimates are saying and that what got published in AR6 turn out closer to the mark - as deeply troubling and as poorly prepared for that as that looks.

Any suggestion that Earth being in a longer term cold climate "state" makes global warming better somehow is utterly preposterous.

 

[weirdoguy]

“Science”

Why did you put science in quotation marks @DOGE3500?

 

[Nugatory]

Why did you put science in quotation marks @DOGE3500?

Charitably, it’s the name of the publication. Uncharitably, it’s misplaced sarcasm.

 

[Ken Fabian]

@DOGE3500 The invitation to expand on your OP and make/argue your point, whatever that point is, remains open. As it is the OP doesn't present a question and as a comment on the Judd et al study it is ambiguous and leaves too much to the reader's assumptions.

My assumption that it is a suggestion global warming is not a big deal (because Earth is in a 'cold state') may reflect my thinking, (I am inclined to take the IPCC and other mainstream science based reports about climate at face value, as if it is fundamentally correct and I get triggered by denial) more than your own thinking; better that you speak for yourself.