Refuting Creationism - The Fossil Record Shows Climate Change - 59-51 Million Years Before 'Creation Week'

Microscopic fossil foraminifera shells

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What microscopic fossilized shells tell us about ancient climate change – @theU

The bad news for creationists continues unabated as science discovers more facts, as we would expect of a counter-factual superstition.

This time it's news that new research led by University of Utah geoscientists has shown how there is a record of climate change in the fossil record in the form of traces of boron isotopes in the fossilised shells of microscopic foraminifera.

The record, 59-51 million years before creationists think Earth was created, is just another record of events in that 99.9975% of Earth's history that creationists try to shoe-horn into 10,000 to make it seem like their childish creation myth has some merit.

The record of change itself depends not on radioactive decay rates but on the ratios of stable isotopes of boron that get incorporated in the shells of microscopic foraminifera during their growth and then remain locked up as their bodies fossilise in marine sediment.

Dating of this marine sediment is done using several strands of evidence, one of which is U-Pb dating of zircon crystals, and all of which converge on the same dates (see the AI panel on the right).
What changes is the ratio of ¹¹B (δ¹¹B) incorporated in the shells of foraminifera during their lifetime, and this is related to the pH of the seawater. pH of sea water is in turn determined by the level of atmospheric CO₂ - the higher the level of CO₂, the lower the pH due to dissolved carbonic acid H₃CO₄.

How can scientists calculate the level of atmospheric CO₂ from measuring the boron in fossil foraminifera shells? Scientists can calculate the level of atmospheric CO₂ from measuring the boron in fossil foraminifera shells by analyzing the boron isotopic composition δ¹¹B and boron concentration within these shells. This process is based on the relationship between boron isotopes and the pH of the seawater in which the foraminifera lived.

Here’s a step-by-step outline of the process:

1. Understanding Boron Isotopes and pH
   • Boron in Seawater: Boron exists in seawater primarily in two forms: boric acid BOH₃ and borate ion BOH₄^-. The ratio of these two forms is pH-dependent.
   • Isotopic Composition: Boric acid and borate ion have different isotopic compositions. The lighter isotope (¹⁰B) preferentially goes into borate, while the heavier isotope (¹¹B) is more common in boric acid.
   • pH Relationship: As the pH of seawater changes, the ratio of boric acid to borate changes, which in turn affects the δ¹¹B ratio. Lower pH (more acidic water) corresponds to higher CO₂ levels in the atmosphere.
2. Foraminifera Shell Formation
   • Shell Composition: Foraminifera incorporate boron from seawater into their calcium carbonate CaCO₃ shells, specifically in the form of borate ions.
   • Recording pH: The δ¹¹B in the shells thus reflects the pH of the seawater at the time the shell was formed.
3. Isotopic Analysis
   • Measuring δ¹¹B: Scientists extract and measure the δ¹¹B in the fossilized shells using techniques like mass spectrometry.
   • Determining Seawater pH: From the δ¹¹B value, the pH of the seawater at the time the foraminifera lived can be reconstructed using established calibration curves that relate δ¹¹B to pH.
4. Inferring Atmospheric CO₂
   • Carbonate Chemistry: The pH of seawater is closely linked to the concentration of dissolved inorganic carbon, including CO₂
   • CO₂ Estimation: With the reconstructed seawater pH, scientists can estimate the partial pressure of CO₂ (pCO₂) in the ocean, which reflects the atmospheric CO₂ levels at that time due to the exchange of CO₂ between the atmosphere and ocean.
5. Calibration and Model Comparison
   • Modeling: To refine the estimates, scientists often use models that incorporate other variables like temperature, salinity, and the concentration of other ions.
   • Cross-checking: They compare the boron-based CO₂ estimates with other proxies (like ice core data) and climate models to validate their results.

Summary

By measuring the boron isotopic composition in fossil foraminifera shells, scientists can reconstruct past seawater pH, which in turn allows them to estimate the CO₂ levels in the atmosphere when these organisms lived. This method provides a crucial window into Earth's past climate and carbon cycle dynamics.

Are the boron isotopes ¹⁰B and ¹¹B stable?

Yes, both boron isotopes ¹⁰B and ¹¹B are stable.

• ¹⁰B has a natural abundance of about 19.9%.
• ¹¹B is more abundant, making up about 80.1% of natural boron.

These isotopes do not undergo radioactive decay, which is why they are considered stable. Their different masses and properties are key to their use in various scientific studies, including the reconstruction of past atmospheric CO₂ levels through foraminifera shells.

How are seabed core sample layers dated?

Dating seabed core sample layers is a critical step in reconstructing Earth's past climate, oceanography, and geological history. Scientists use a combination of dating methods to determine the ages of the layers in seabed cores. Here are the main methods employed:

1. Radiometric Dating (Radiocarbon Dating)
   • Method: Radiocarbon dating (¹⁴C) is used to date layers up to about 50,000 years old. It measures the decay of radioactive carbon in organic material (e.g., shells or microorganisms) within the sediment.
   • Applications: Best for dating sediments containing organic matter, like microfossils or plant debris.
2. Biostratigraphy
   • Method: This involves identifying and dating layers based on the presence of fossilized remains of microorganisms, such as foraminifera, diatoms, and radiolarians, whose evolutionary changes are well-documented over time.
   • Applications: Useful for dating cores over millions of years, relying on known fossil ranges and extinction events.
3. Magnetostratigraphy
   • Method: This technique uses the Earth's magnetic field reversals, which are recorded in the alignment of magnetic minerals in the sediments. By matching these recorded magnetic patterns to the known geomagnetic polarity time scale, the age of the sediments can be determined.
   • Applications: Effective for dating older sediment layers, as the geomagnetic polarity scale extends over millions of years.
4. Tephrochronology
   • Method: This technique involves identifying and dating volcanic ash layers (tephra) within the core. Each volcanic eruption has a unique geochemical fingerprint, allowing scientists to correlate and date the ash layer.
   • Applications: Highly precise when volcanic layers are present, as each tephra layer can be linked to a specific eruption.
5. Stable Isotope Stratigraphy
   • Method: This method involves measuring variations in stable isotopes, such as oxygen (¹⁸/¹⁶), which reflect changes in climate and ice volume. These changes are globally synchronous and can be matched to a global isotope stratigraphy.
   • Applications: Useful for dating and correlating marine sediments globally, especially during glacial and interglacial cycles.
6. Paleomagnetic and Orbital Tuning
   • Paleomagnetic: Aligns changes in sediment magnetism to known historical magnetic field changes.
   • Orbital Tuning: Correlates sediment layers to Milankovitch cycles (variations in Earth's orbit), which affect climate and sediment deposition patterns.
7. Layer Counting (Varve Chronology)
   • Method: In some environments, sediments accumulate in seasonal layers known as varves. Counting these layers provides a direct age estimate.
   • Applications: Effective in regions with distinct seasonal deposits, like glacial lakes.
8. Lead-210 Dating (²¹⁰Pb)
   • Method: Used for dating recent sediments (up to about 150 years old) by measuring the decay of (²¹⁰Pb), a naturally occurring radioactive isotope.
   • Applications: Particularly useful for dating recent sediments in lakes, oceans, and wetlands.

Combining Methods

• Composite Dating: Often, multiple methods are used in combination to cross-check and refine the dating accuracy. For instance, radiocarbon dating might be combined with biostratigraphy or paleomagnetic data to produce a robust age model for the core.

These methods allow scientists to construct a detailed timeline of sediment deposition, which can be used to interpret changes in past climate, ocean circulation, and other Earth processes.

For details, see the AI panel on the right.

The findings of the University of Utah (THEU) team are the subject of a paper in Proceeding of the National Academy of Science (PNAS) and a THEU news release:

What microscopic fossilized shells tell us about ancient climate change

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New research from U geologists links rapid climate change 50 million years ago to rising CO₂ levels.

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At the end of the Paleocene and beginning of the Eocene epochs, between 59 to 51 million years ago, Earth experienced dramatic warming periods, both gradual periods stretching millions of years and sudden warming events known as hyperthermals.

Driving this planetary heat-up were massive emissions of carbon dioxide (CO₂) and other greenhouse gases, but other factors like tectonic activity may have also been at play.

New research led by University of Utah geoscientists pairs sea surface temperatures with levels of atmospheric CO₂ during this period, showing the two were closely linked. The findings also provide case studies to test carbon cycle feedback mechanisms and sensitivities critical for predicting anthropogenic climate change as we continue pouring greenhouse gases into the atmosphere on an unprecedented scale in the planet’s history.

Images of forams created by a scanning electronic microscope.

Credit: Dustin Harper

The main reason we are interested in these global carbon release events is because they can provide analogs for future change. We really don’t have a perfect analog event with the exact same background conditions and rate of carbon release.

Dr. Dustin T. Harper, lead author Department of Geology & Geophysics
University of Utah, Salt Lake City, UT, USA.

But the study published Monday in the Proceedings of the National Academy of Sciences, or PNAS, suggests emissions during two ancient “thermal maxima” are similar enough to today’s anthropogenic climate change to help scientists forecast its consequences.

The research team analyzed microscopic fossils—recovered in drilling cores taken from an undersea plateau in the Pacific—to characterize surface ocean chemistry at the time the shelled creatures were alive. Using a sophisticated statistical model, they reconstructed sea surface temperatures and atmospheric CO₂ levels over a 6-million-year period that covered two hyperthermals, the Paleocene-Eocene Thermal Maximum, or PETM, 56 million years ago and Eocene Thermal Maximum 2, ETM-2, 54 million years ago.

The findings indicate that as atmospheric levels of CO₂ rose, so too did global temperatures.

Dustin Harper, right, a University of Utah geoscientist, discusses drilling cores with colleague Weimu Xu of University College Dublin aboard a research vessel operated by the International Ocean Discovery Program.

Credit: Sandra Herrmann

We have multiple ways that our planet, that our atmosphere is being influenced by CO₂ additions, but in each case, regardless of the source of CO₂, we’re seeing similar impacts on the climate system. “We’re interested in how sensitive the climate system was to these changes in CO₂. And what we see in this study is that there’s some variation, maybe a little lower sensitivity, lower warming associated with a given amount of CO₂ change when we look at these very long-term shifts. But that overall, we see a common range of climate sensitivities.

Professor Gabriel Bowen, co-author
Professor of geology & geophysics
Department of Geology and Geophysics
University of Utah, Salt Lake City, UT, USA.

Today, human activities associated with fossil fuels are releasing carbon 4 to 10 times more rapidly than occurred during these ancient hyperthermal events. However, the total amount of carbon released during the ancient events is similar to the range projected for human emissions, potentially giving researchers a glimpse of what could be in store for us and future generations.

First scientists must determine what happened to the climate and oceans during these episodes of planetary heating more than 50 million years ago.

These events might represent a mid- to worst-case scenario kind of case study. We can investigate them to answer what’s the environmental change that happens due to this carbon release?

Dr. Dustin T. Harper.

Earth was very warm during the PETM. No ice sheets covered the poles and ocean temperatures were in the mid-90s degrees Fahrenheit.

To determine oceanic CO₂ levels the researchers turned to fossilized remains of foraminifera, a shelled single-cell organism akin to plankton. The research team based the study on cores previously extracted by the International Ocean Discovery Program at two locations in the Pacific.

The foram shells accumulate small amounts of boron, the isotopes of which are a proxy reflecting CO₂ concentrations in the ocean at the time the shells formed, according to Harper.

We measured the boron chemistry of the shells, and we’re able to translate those values using modern observations to past seawater conditions. We can get at seawater CO₂ and translate that into atmospheric CO₂. The goal of the target study interval was to establish some new CO₂ and temperature records for the PETM and ETM-2, which represent two of the best analogs in terms of modern change, and also provide a longer-term background assessment of the climate system to better contextualize those events.

Dr. Dustin T. Harper.

The cores Harper studied were extracted from Shatsky Rise in the subtropical North Pacific east of Japan, which is an ideal location for recovering ocean-bottom sediments that reflect conditions in the ancient past.

Carbonate shells dissolve if they settle into the deep ocean, so scientists must look to underwater plateaus like Shatsky Rise, where the water depths are relatively shallow. While their inhabitants were living millions of years ago, the foraminifera shells record the sea surface conditions.

Then they die and sink to the sea floor, and they’re deposited in about two kilometers of water depth. We’re able to retrieve the complete sequence of the dead fossils. At these places in the middle of the ocean, you really don’t have a lot of sediment supply from continents, so it is predominantly these fossils and that’s all. It makes for a really good archive for what we want to do.

Dr. Dustin T. Harper.

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The study “Long- and short-term coupling of sea surface temperature and atmospheric CO₂ during the late Paleocene and early Eocene,” was published Aug. 26 in the Proceedings of the National Academy of Sciences, or PNAS. Funding came from the National Science Foundation. The research was conducted in collaboration with colleagues at Columbia University, University of California Santa Cruz, Vassar College, Utah State University and University of Hawaii.

Significance
From approximately 59 to 51 million years ago, Earth experienced long-term warming during which multiple short-lived global warming events occurred. These events are considered among the best geologic analogs to anthropogenic carbon dioxide release. Here, we use new and published geochemical measurements from Pacific Ocean microfossils that lived 59 to 53 million years ago to calculate atmospheric carbon dioxide and sea surface temperature using a statistical model. We use these results to compute the sensitivity of regional climate to atmospheric CO₂ for long-term warming and the abrupt events. Our findings suggest an influence of plate tectonics on long-term warming and refine constraints on the source and amount of CO₂ released across the multiple timescales of global warming assessed here.

Abstract
The late Paleocene and early Eocene (LPEE) are characterized by long-term (million years, Myr) global warming and by transient, abrupt (kiloyears, kyr) warming events, termed hyperthermals. Although both have been attributed to greenhouse (CO₂) forcing, the longer-term trend in climate was likely influenced by additional forcing factors (i.e., tectonics) and the extent to which warming was driven by atmospheric CO₂ remains unclear. Here, we use a suite of new and existing observations from planktic foraminifera collected at Pacific Ocean Drilling Program Sites 1209 and 1210 and inversion of a multiproxy Bayesian hierarchical model to quantify sea surface temperature (SST) and atmospheric CO₂ over a 6-Myr interval. Our reconstructions span the initiation of long-term LPEE warming (~58 Ma), and the two largest Paleogene hyperthermals, the Paleocene–Eocene Thermal Maximum (PETM, ~56 Ma) and Eocene Thermal Maximum 2 (ETM-2, ~54 Ma). Our results show strong coupling between CO₂ and temperature over the long- (LPEE) and short-term (PETM and ETM-2) but differing Pacific climate sensitivities over the two timescales. Combined CO₂ and carbon isotope trends imply the carbon source driving CO₂ increase was likely methanogenic, organic, or mixed for the PETM and organic for ETM-2, whereas a source with higher δ¹³C values (e.g., volcanic degassing) is associated with the long-term LPEE. Reconstructed emissions for the PETM (5,800 Gt C) and ETM-2 (3,800 Gt C) are comparable in mass to future emission scenarios, reinforcing the value of these events as analogs of anthropogenic change.

Harper, Dustin T.; Hönisch, Bärbel; Bowen, Gabriel J.; Zeebe, Richard E.; Haynes, Laura L.; Penman, Donald E.; Zachos, James C."
Long- and short-term coupling of sea surface temperature and atmospheric CO₂ during the late Paleocene and early Eocene Proceedings of the National Academy of Sciences 121(36) e2318779121; DOI: 10.1073/pnas.2318779121

Copyright: © 2024 The authors.
Published by PNAS. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)

The problem for creationists is that the picture which emerges is not that of a fine-tunes, perfect Earth created for life, but an Earth subject to dynamic change and mass extinctions due to, for instance, climate change, atmospheric temperature variations and changes in atmospheric gasses. The fossilised bodies of these microorganisms simply contain a record of these changes over time.

The basic principle of changes in the ratios of boric acid (B(OH)₃) and borate ions (B(OH)₄^-) with a differential inclusion of ¹⁰B and ¹¹B, is something that can be reproduced and tested in a laboratory, as is the consequential differential inclusion of the different stable isotopes of boron in the shells of foraminifera.

So, creationists are stuck with trying to ignore and/or refute something that is demonstrably true - unless, of course, they go completely off the rails and start claiming chemistry and physics used to behave differently, while pretending life could be created with different laws of chemistry and physics, in the same Universe they claim is 'fine-tuned' for life.

All creationists need do to successfully ignore this evidence is to explain how a creator god contrived to make marine sediment look tens of millions of years old and the record of boron isotopes in microscopic fossils in that sediment look like a record of climate change several million years ago.

Or they can use their usual intellectually bankrupt tactic of pretending they haven't heard of it.

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