Troubled waters

[CrusaderFrank]

Abstract​

We summarize the applications of molecular proxies in paleoclimatology. Marine molecular records especially are proving to be of value but certain environmentally persistent compounds can also be measured in lake sediments, loess deposits and ice cores. The fundamentals of this approach are the molecular parameters, the compound abundances and carbon, hydrogen, nitrogen and oxygen isotopic contents which can be derived by the analysis of sediment extracts. These afford proxy measures which can be interpreted in terms of the conditions which control climate and also reflect its operation.
We discuss two types of proxy; those of terrigenous and those of aquatic origin, and exemplify their application in the study of marine sediments through the medium of ten case studies based in the Atlantic, Mediterranean and Pacific Oceans, and in Antarctica. The studies are mainly for periods in the present, the Holocene and particularly the last glacial/interglacial, but they also include one study from the Cretaceous. The terrigenous proxies, which are measures of continental vegetation, are based on higher plant leaf wax compounds, i.e. long-chain (circa C30) hydrocarbons, alcohols and acids. They register the relative contributions of C3 vs. C4 type plants to the vegetation in the source areas. The two marine proxies are measures of sea surface temperatures (SST). The longer established one, (U37K′) is based on the relative abundances of C37 alkenones photosynthesized by unicellular algae, members of the Haptophyta. The newest proxy (TEX86) is based on C86 glycerol tetraethers (GDGTs) synthesized in the water column by some of the archaeal microbiota, the Crenarchaeota.

Molecular proxies for paleoclimatology

We summarize the applications of molecular proxies in paleoclimatology. Marine molecular records especially are proving to be of value but certain env…

www.sciencedirect.com

Nothing about temperature in here

Look, life's too short, stop wasting my time

 

[CrusaderFrank]

It's appears possible such information can be determined:

Oceans heating up faster now than in the past 10,000 years, says new study

"If the latest research is correct, our oceans are heating up much faster now than they have in the past 10,000 years.

"This is one of the conclusions that is drawn from a recently published paper in Science.

"The researchers (Yair Rosenthal, Braddock Linsley, and Delia Oppo) cleverly traveled back in time to explore how ocean temperatures have changed.

"Comparison of those temperatures to today's helped them quantify the impact that human greenhouse gas emissions are having on the planet.

"The story begins in a remote location in the western equatorial Pacific. Using sediments along the Makassar Straight and the Flores Sea in Indonesia, the researchers extracted benthic foraminifera, which are small creatures that live near or at the bottom of the ocean waters. The chemical signatures in the shells of these creatures can provide valuable information about the ocean temperature in the recent or long past."

Up to date CO2 reading disputes the very notion of "human greenhouse gas emissions are causing unnaturally rapid ocean warming"

The global economy shut down, yet CO2 was unaffected

Time for a new theory

 

[CrusaderFrank]

It's appears possible such information can be determined:

Oceans heating up faster now than in the past 10,000 years, says new study

"If the latest research is correct, our oceans are heating up much faster now than they have in the past 10,000 years.

"This is one of the conclusions that is drawn from a recently published paper in Science.

"The researchers (Yair Rosenthal, Braddock Linsley, and Delia Oppo) cleverly traveled back in time to explore how ocean temperatures have changed.

"Comparison of those temperatures to today's helped them quantify the impact that human greenhouse gas emissions are having on the planet.

"The story begins in a remote location in the western equatorial Pacific. Using sediments along the Makassar Straight and the Flores Sea in Indonesia, the researchers extracted benthic foraminifera, which are small creatures that live near or at the bottom of the ocean waters. The chemical signatures in the shells of these creatures can provide valuable information about the ocean temperature in the recent or long past."

 

[georgephillip]

Oceans heating up faster now than in the past 10,000 years, says new study

"After analyzing the foraminifera shells, the authors concluded that ocean waters at mid-depths were warmer during the early/middle Holocene (about 10,000 to 8,000 years ago) then they are today.

"Over the next few thousand years, the oceans cooled.

"Then, in recent decades, there was a significant change as the oceans began to heat quickly.

"Here is what the author himself had to say:

"'It is clear that much of the heat that humans have put into the atmosphere through greenhouse gas emissions will be absorbed by the ocean. But the absorption time takes hundreds of years, much longer than the current rate of warming and the planet will keep warming. Our study puts the modern observations into a long-term context. Our reconstruction of Pacific Ocean temperatures suggests that in the last 10,000 years, the Pacific mid-depths have generally been cooling by about 2 degrees centigrade until a minimum about 300 years during the period known as the Little Ice Age.
After that, mid-depth temperatures started warming but at a very slow rate. Then, since about 1950, temperatures from just below the sea surface to ~1000 meter, increased by 0.18 degrees C'

"'This seemingly small increase occurred an order of magnitude faster than suggested by the gradual change during the last 10,000 years thereby providing another indication for global warming. But our results also show the temperature of the ocean interior is still much colder than at any time in the past 10,000 years thus, lagging the changes we see at the ocean surface.'"

 

[ding]

Oceans heating up faster now than in the past 10,000 years, says new study

"After analyzing the foraminifera shells, the authors concluded that ocean waters at mid-depths were warmer during the early/middle Holocene (about 10,000 to 8,000 years ago) then they are today.

"Over the next few thousand years, the oceans cooled.

"Then, in recent decades, there was a significant change as the oceans began to heat quickly.

"Here is what the author himself had to say:



"'This seemingly small increase occurred an order of magnitude faster than suggested by the gradual change during the last 10,000 years thereby providing another indication for global warming. But our results also show the temperature of the ocean interior is still much colder than at any time in the past 10,000 years thus, lagging the changes we see at the ocean surface.'"

Increased climate fluctuation and environmental uncertainty are artifacts of a bipolar glaciated world where the threshold for extensive northern hemisphere continental glaciation is lower than the threshold for extensive southern hemisphere continental glaciation.