The article has this response from Michael Mann:
The timeline, published Thursday in the journal Science, is the most
rigorous reconstruction of Earth’s past temperatures ever produced, the
authors say. ...
Michael Mann, a climate scientist at the University of Pennsylvania who is known for his analyses of past global temperatures, said he was also surprised by the suggestion that the planet got so warm. The finding supports many scientists’ concern that feedback loops in the Earth system could lead to much higher temperatures than most climate models predict, he wrote in an email. But it’s also possible that the data assimilation assumes too much warming and is missing factors that might forestall a runaway greenhouse effect. “While I applaud the authors for this ambitious and thoughtful study, I am skeptical about the specific, quantitative conclusions,” Mann said. ...
Even under the worst-case scenarios, human-caused warming will not push the Earth beyond the bounds of habitability.
The article, which places us today in some of the still coolest climate conditions in 500 million years, never connects the dots.
It maintains that a dramatic warming event 250 million years ago caused the largest mass extinction ever, spewing carbon dioxide and other gases into the atmosphere, 25 million years BEFORE the first mammals appeared, who breathe the OXYGEN emitted by carbon dioxide consuming PLANTS, who then in their turn THRIVED for 125 million years under EVEN WARMER conditions than that extinction event produced.
Evolution was evidently turbocharged by this warming and its carbon dioxide, but then suddenly the first humans supposedly started to evolve 6.5 million years ago at the end of 50 million years of cooling conditions, WHEN THE TEMPERATURE WAS 62.6 F*, and continued to evolve into modern humans 300,000 years ago just as temperature KEPT FALLING to the coldest point in the record (51.8 F).
How did that happen?
The study authors are worried about what warmer conditions in the future will mean for humans, but seem oddly uninterested in how humans supposedly evolved in relatively much cooler conditions.
Maybe we don't really understand the evolution of mammals. Maybe humans are much older than the record indicates, and much more resilient.
At
its hottest, the study suggests, the Earth’s average temperature
reached 96.8 degrees Fahrenheit (36 degrees Celsius) — far higher than
the historic 58.96 F (14.98 C) the planet hit last year. ...
At the timeline’s start, some 485 million years ago, Earth was in what is known as a hothouse climate, with no polar ice caps and average temperatures above 86 F (30 C). ...
For most of the Phanerozoic, the research suggests, average temperatures have exceeded 71.6 F (22 C), with little or no ice at the poles. ...
But humans evolved during the coldest epoch of the Phanerozoic, when global average temperatures were as low as 51.8 F (11 C).
Without rapid action to curb greenhouse gas emissions,
scientists say, global temperatures could reach nearly 62.6 F (17 C)
by the end of the century — a level not seen in the timeline since the
* Miocene epoch, more than 5 million years ago.
