What Happened to the Dinosaurs?

CSS-48 The prevailing theory lays the blame on a major celestial impact (tied to the Chicxulub impact site on the Yucatan Peninsula in Mexico). A recent paper by Cox-Keller (or more accurately the alarmist spin) postulates that the extinction may have been caused by you guessed correctly, “climate change” (and toxic gases). As with all “climate change” alarmist propaganda, the “proof” lies in the models. From the Daily Caller article, “The model found climate-warming gases from ‘Deccan Traps’ volcanoes were enough to drive the dinosaurs to extinction 300,000 years before the asteroid”. There are some problems with that hypothesis.

#climatechange #delaythegreen #globalwarming #showusthedata

1. Very little of those “climate-warming gases” were released pre-Chicxulub based on the Cox-Keller graphs. Peak CO₂ rates, pre-Chicxulub were just ±0.05 Gt/year (averaging less than that, probably 3,000 Gt total). Post-Chicxulub rates were not much higher with a peak rate of just 0.20 Gt/year.
2. How could CO₂ emissions of 0.20 Gt/year be dangerous, let alone provide effective warming? Humanity has added 1,466 Gt since 1950 (an average of 20.4 Gt/year).
3. There was a temperature rise (from 66.35 to 66.25 Ma ago) visible in the benthic foraminifera oxygen isotope ratio (δO₁₈) data, but there is no CO₂ response in the carbon isotope ratio (δC₁₃) data (consistent with the Cox-Keller graphs). CO₂ was obviously not responsible for that 100,000-year temperature increase (roughly 1.7 °C) since CO₂ concentrations were not rising.
4. From 66.25 Ma ago to ≈66 Ma ago (the Chicxulub impact) temperatures dropped ≈2.2 °C (back to the levels pre-Deccan Traps). This would be the more typical response from volcanic activity. The Sulfur Oxides, ash and other particulate emissions cool the planet. CO₂ was also falling despite the volcanic CO₂ emissions.
5. There was an abrupt change in both CO₂ concentrations and global temperatures when Chicxulub hit. Temperatures started rising almost immediately, followed by CO₂ concentration increases. There may have been a short-term temperature drop (due to the material blasted into the atmosphere) that was lost in the data resolution. That increase in CO₂ is likely due to a combination of volcanic emissions and the natural temperature recovery.
6. The authors are using computer models to produce their results. If they use the same input parameters and algorithms used by the IPCC computer models, their results are immediately suspect. Remember the IPCC models run way too hot, by the modelers’ own admissions. The IPCC models run too hot because they assume/program their computers to respond almost exclusively to CO₂ emissions by using unrealistically high CO₂ climate sensitivities and ignoring the many, more dominant natural forcings.
7. The temperature/CO₂ changes in the isotope ratio data around the Chicxulub Event (up or down) are not enough to cause reptile (i.e.: dinosaur) extinctions. Dinosaurs existed on the planet for roughly 170 million years and experienced/survived much larger temperature fluctuations. Also, they like warm temperatures.

The story being put forward is based on computer models. The authors (based on the article comments) have tried to paint a picture that their modeling techniques have taken out the human emotions/biases. That of course is impossible. Somebody had to be responsible for the input parameters, algorithms, underlying equations, etc. Also, I saw no mention of orbital cycles which would play a role on those time scales. The Cretaceous period was a lot warmer than our current temperatures but would still have warmed and cooled based on that period’s “Milankovitch Cycles”. The temperature fluctuations are likely less dramatic than our current ice age because the planet had little to no ice back in the Cretaceous/Eocene period. So, yes there are human biases imbedded in the results.

The following quote comes from the Supplementary data. “Without any priors, we see that just three environmental forcings (carbon, sulfur, and organic carbon export), can still recreate extinction conditions, but since there are only three outputs, this makes sense.” I have no doubt that the authors could recreate extinction conditions in their models. But the pre-Chicxulub volcanic emission totals were minor with most of the emissions occurring post-Chicxulub (i.e.: post the extinction event). Could the emissions affect temperatures and introduced toxic gases? Yes, but according to the isotope ratio data the temperatures were rising prior to the Deccan Traps eruptions (while CO₂ remained flat) then began dropping (along with CO₂ levels) when the Deccan Traps began erupting (typical for volcanic eruptions). Why would CO₂ levels be dropping while the Deccan Traps were erupting and emitting CO₂? Obviously, the emissions are less than the other forces controlling CO₂. The isotope ratios post-Chicxulub show a relatively minor temperature and CO₂ increase. With temperature responding almost immediately to the Chicxulub impact and CO₂ following shortly after. The CO₂ temperature contribution is dependent on the climate sensitivity.

I cannot provide a definitive opinion on the Cox-Keller detailed interpretation, but based on the benthic foraminifera isotope ratio data, the temperature changes over this 2 Ma period do not appear to be enough to invoke a significant extinction event. The Deccan Traps could have contributed to the extinction event based on the 2+ °C temperature drop pre-Chicxulub impact and the toxic gas releases. But those pre-Chicxulub emissions were relatively minor and at the most might have weakened the dinosaur population slightly. Weakened or not, the Chicxulub impact was the kill shot. If the Deccan Traps were responsible for the extinction event, CO₂ does not appear to be a factor. So, “Climate Change” as defined by the alarmist community (effectively all CO₂, all the time) could not have been responsible.

CSS-48h – What Happened to the Dinosaurs? Addendum

The science is never settled. Shortly after sending out my CSS-48 – What Happened to the Dinosaurs? Post, I was watching an older video from Professor Ian Plimer which outlined the possibility that the dinosaurs (at least some of them) survived the impact and were not completely wiped out for another 300,000 years. In that scenario, the volcanic Deccan Traps could have certainly played the final role in the dinosaurs’ demise. The long-term, excessive, and relatively steady volcanic emissions (ash, sulfur compounds, etc.) could have contributed to sustained atmospheric toxicity. Photosynthesis complications and acid rain could have reduced the quality of plant life, leading to starvation in the remaining dinosaur population.

#climatechange #delaythegreen #globalwarming #showusthedata

I did some research on but did not find much definitive information on a prolonged extinction event, but it is certainly possible. I also did not find any definitive information that CO₂ played a role in the extinction event. The temperature changes in the oxygen isotope ratio (δO₁₈) data (indicative of temperature changes) were not significant enough to have given the dinosaurs any noticeable grief. The temperatures through this period were well within the normal range of the dinosaurs’ 170-million-year reign. Dinosaurs are reptiles, they like warm temperatures. Of course, this far back in time, there could be short duration spikes and dips in temperature that are beyond the resolution of the data. For instance, the Chicxulub impact, probably threw enough material into the atmosphere to block out the sun’s energy/light for several years. Probably not enough temperature drop, given the higher temperatures to begin with, to drop the planet into anything close to an ice age. But the reduced temperatures and sunlight would have had serious complications to the quality of life for the impact survivors (both plant and animal).

Given, the Chicxulub impact size, I would suggest that the impact was still the most significant factor. The impact (based on the Cox-Keller emission chart) may have helped accelerate the Deccan Traps eruption. Emissions post-impact were significantly higher than those pre-impact. Whatever the ultimate demise, CO₂ had very little to do with dinosaur extinction.

For more perspective and more detailed analysis, you can check out some of the following posts. Thes are the same posts as the original CSS-48 posting. The video from Ian Plimer (well worth the watch for a great historical “Climate Change” overview) was added to the list.

Professor Ian Plimer – 2013 Climate Change Presentation

(5) Australský geolog Ian Plimer na FŽP – YouTube.

Dinosaurs may NOT have been wiped out by world-ending meteor: New model says mega volcano eruption may have caused their extinction

https://www.dailymail.co.uk/sciencetech/article-12572679/Dinosaurs-extinction-asteroid-climate-change-volcano-simulation-Deccan-Traps-Chicxulub.html

A Bayesian inversion for emissions and export productivity across the end-Cretaceous boundary (Cox, A. A, Keller, C.B. – September 2023)

https://www.science.org/doi/10.1126/science.adh3875

An astronomically dated record of Earth’s climate and its predictability over the last 66 million years

https://www.researchgate.net/publication/344230305_An_astronomically_dated_record_of_Earth’s_climate_and_its_predictability_over_the_last_66_million_years

Reconciling atmospheric CO₂, weathering, and calcite compensation depth across the Cenozoic

https://www.researchgate.net/publication/348700136_Reconciling_atmospheric_CO_2_weathering_and_calcite_compensation_depth_across_the_Cenozoic

One Page Summary (OPS)

OPS-55 – The State of Climate Science

The State of Climate Science

Climate Short Story (CSS)

CSS-10 – A Ride Through the Cenozoic

A Ride Through The Cenozoic

CSS-21 – CO₂ – Visualized Temperature Contribution?

CO2 – Visualized Temperature Contribution