Recent Songliao Basin data, global warming

[overtone]

The July 12 Science magazine has an article (p 1185, unfortunately I think it's behind a paywall) describing some results obtained by Wang Chengshan's team's sediment core drilling in the Songliao Basin.

 

The drill samples have crossed the KT boundary and much of the Cretaceous below it, including the Deccan Traps eruptions. Their findings are startling - the Deccan Traps huge episodes of volcanism put the climate of the planet on a roller coaster leading into the KT asteroid event. The boost of CO2 from the most severe of the Deccan Trap volcanism episodes (there were several) apparently doubled atmospheric CO2 in less than 10,000 years, more than 1/20th of the current boost rate, and this raised temperatures rapidly and significantly - 20 degrees centigrade, in the nearby region ( inland, not oceanic).

 

This correlates with a serious extinction trend among large dinosaurs, preceding the KT asteroid extinction event and leading into it.

Edited July 20, 2015 by overtone

[MigL]

Everything I've previously read about the Deccan Trapp events indicated that there were large releases of SO2 into the atmosphere with a resulting drop in temperatures of several degrees. I've even read that the meteoric extinction event may have caused the volcanic instability related to Deccan Trapp.

 

If this data is confirmed it may even change our thinking on the cause of the large extinction as not being solely due to asteroid collision.

[overtone]

Everything I've previously read about the Deccan Trapp events indicated that there were large releases of SO2 into the atmosphere with a resulting drop in temperatures of several degrees

More recent work includes the effects of CO2.

 

The standard view was the the SO2 effects were quick and short term, while the CO2 effects were longer term and allowed the plants and animals time to adjust, thus failing to explain major extinction waves - http://www.princeton.edu/main/news/archive/S41/89/26O49/index.xml?section=topstories

 

The very recent reports referred to in the OP appear to tighten the timeline for the CO2 boost dramatically, and also tighten the timeline for the consequent temperature boost - CO2 doubling in less than ten thousand years, or almost 5% as fast as the current anthro boosting, and temperatures rising in synchrony, with predictable climate changes. That is faster than most large organisms can handle, and does explain the extinction trend that appears to have taken hold in the period leading up to the asteroid wipeout (and helps account for the severity of the asteroid's effects).

Edited July 20, 2015 by overtone

[MigL]

So flora and fauna had enough time to adapt to the slowly rising temps due to CO2 increases, and once adapted, were even more susceptible to the rapid temp drops caused by the sunlight blocking dust and gas in the atmosphere after the asteroid impact ?

[overtone]

 

 

So flora and fauna had enough time to adapt to the slowly rising temps due to CO2 increases, and once adapted, were even more susceptible to the rapid temp drops caused by the sunlight blocking dust and gas in the atmosphere after the asteroid impact ?

That was one of the old views, which this new report - if it checks out - contradicts.

 

There was an extinction trend in the era leading up to the asteroid impact, and the new research findings would help considerably in explaining it as well as the severity of the asteroid's consequences.

[MigL]

I don't see the difference or contradiction.

 

Rising temps due to CO2 increases forced adaptation.

That doesn't mean an existing specie 'changes' to better suit the environment (hotter ).

It means some species become extinct while other species, better suited to the new, hotter environment, survive.

 

So, yes extinctions would have started long before the asteroid impact. Just as some species are now becoming extinct because of AGW ( maybe even us eventually ).

 

But the species that were suited to the new hotter environment, found it much more difficult to survive the global cooling brought on by the asteroid impact. Maybe if there had been no warming trend before the asteroid impact, many more species would have survived, and you might now be discussing this with a fellow velociraptor.

[overtone]

 

 

I don't see the difference or contradiction.

Rising temps due to CO2 increases forced adaptation.

That doesn't mean an existing specie 'changes' to better suit the environment (hotter ).

It means some species become extinct while other species, better suited to the new, hotter environment, survive.

Oh, sure. I was confused by your description of "slowly rising temperatures". They rose very rapidly, in synchrony with the dramatic boosting of CO2 levels, was the key finding.