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The Pliocene: The Last Time Earth had >400 ppm of Atmospheric CO2
- Thread starter abu afak
- Start date
Not only is 3 million years a significant length of time, it was, as you note, 2 million, 800 thousand years before the appearance of homo sapiens. Since that time, the Earth has experienced over a dozen glaciations, the "ice ages" of lay parlance. Those who wish to suggest that the current warming is simply part of the normal glacial/interglacial cycle need to explain why the current level of CO2 was never even approached in ANY of the past interglacial periods.
Toddsterpatriot
Diamond Member
In Response to Climate Change, Citizens in Advanced Economies Are Willing To Alter How They Live and Work
Citizens offer mixed reviews of how their societies have responded to climate change, and many question the efficacy of international efforts to stave off a global environmental crisis.www.pewresearch.org
In Response to Climate Change, Citizens in Advanced Economies Are Willing To Alter How They Live and Work
Yes, they are. Poor people in Germany are willing to choose between heat and food.
Reducing the temperature in 2100 by 0.1 degrees is the best reason to starve yourself.
You know, Todd, you haven't had a pertinent or meaningful response to anything I've posted in a very long while. It's always these cute little quips and jabs. Have you run out or are you just unable to justify the effort anymore?
Toddsterpatriot
Diamond Member
Your emotional posts require very little response.
You're like a girl in college, crying all day because we're doomed. Fucking Exxon!
Have you glued yourself to a road yet? I can see you in an orange Stop Oil shirt, blocking traffic, feeling you're saving the planet.
jc456
Diamond Member
- Dec 18, 2013
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There’s evidence man was here many different times. You’re again wrong
Really? Could you show us some of that evidence?
jc456
Diamond Member
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Look it up? Here…..
Human Timeline: How Long Have Humans Existed? - Earth How
The earliest anatomically modern human fossil found was dated at about 200-300,000 years old in Morocco, Africa. They had modern faces and used stone tools.
earthhow.com
Co2 is plant food.
You need to explain what you meant by "There’s evidence man was here many different times."Look it up? Here…..
Human Timeline: How Long Have Humans Existed? - Earth How
The earliest anatomically modern human fossil found was dated at about 200-300,000 years old in Morocco, Africa. They had modern faces and used stone tools.
jc456
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You haven’t heard of the pyramids? How do you think they cut the stones?
Billy_Bob
Diamond Member
This OP is laughable.
WE have had levels of CO2 regularly go above 400ppm in our current interglacial.
Come on AbuFkFK... you can do better than this drivel..
WE have had levels of CO2 regularly go above 400ppm in our current interglacial.
Come on AbuFkFK... you can do better than this drivel..
Speaking of drivel: some discussion regarding the comparative accuracy of ice core and stomata-based CO2 measurements
Firstly, ice-core CO2 measurements are direct measurements on air that has been enclosed in bubbles. On the other hand, stomatal density is an indirect measure. Experiments on stomata density showed that "the stomatal response to increasing atmospheric CO2 was identical to that induced by removing water from the plant roots" (Idso et al 1984). In other words, stomatal index data may not be the able to measure the atmospheric concentration as precisely as its proponents would like.
Secondly, several different ice-core data sets are essentially consistent. Artifacts do appear in earlier ice core records - mainly the Greenland drill sites where CO2 was depleted through a chemical reaction - but there are no such indications of this in the Taylor Dome ice core. In any event, this is a known phenomena, and one that can be accounted for. These records all indicate the CO2 concentration from 260 to 280 ppmv during the preindustrial Holocene.
Stomata data, on the other hand, do not show such agreement. For example Beerling et al (D. J. Beerling, H. H. Birks, F. I. Woodward, J. Quat. Sci. 10, 379 (1995)) report largely scattering proxy CO2 values from 225 to 310 ppmv between 9940 and 9600 14C-yr, in disagreement with the data presented by Wagner et al.
In summary, the skeptics claim that stomatal data falsify the concept of a relatively stable Holocene CO2 concentration of 270-280 ppmv until the Industrial Revolution. This claim is not justified.
Stomatal data vs ice core measurements to measure CO2 levels
Examines the science and arguments of global warming skepticism. Common objections like 'global warming is caused by the sun', 'temperature has changed naturally in the past' or 'other planets are warming too' are examined to see what the science really says.
skepticalscience.com
Why wouldn't an atmospheric physicist know this?
jc456
Diamond Member
- Dec 18, 2013
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Speaking of drivel: some discussion regarding the comparative accuracy of ice core and stomata-based CO2 measurements
Firstly, ice-core CO2 measurements are direct measurements on air that has been enclosed in bubbles. On the other hand, stomatal density is an indirect measure. Experiments on stomata density showed that "the stomatal response to increasing atmospheric CO2 was identical to that induced by removing water from the plant roots" (Idso et al 1984). In other words, stomatal index data may not be the able to measure the atmospheric concentration as precisely as its proponents would like.Secondly, several different ice-core data sets are essentially consistent. Artifacts do appear in earlier ice core records - mainly the Greenland drill sites where CO2 was depleted through a chemical reaction - but there are no such indications of this in the Taylor Dome ice core. In any event, this is a known phenomena, and one that can be accounted for. These records all indicate the CO2 concentration from 260 to 280 ppmv during the preindustrial Holocene.Stomata data, on the other hand, do not show such agreement. For example Beerling et al (D. J. Beerling, H. H. Birks, F. I. Woodward, J. Quat. Sci. 10, 379 (1995)) report largely scattering proxy CO2 values from 225 to 310 ppmv between 9940 and 9600 14C-yr, in disagreement with the data presented by Wagner et al.In summary, the skeptics claim that stomatal data falsify the concept of a relatively stable Holocene CO2 concentration of 270-280 ppmv until the Industrial Revolution. This claim is not justified.Stomatal data vs ice core measurements to measure CO2 levels
Examines the science and arguments of global warming skepticism. Common objections like 'global warming is caused by the sun', 'temperature has changed naturally in the past' or 'other planets are warming too' are examined to see what the science really says.skepticalscience.com
Why wouldn't an atmospheric physicist know this?
A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
As the most abundant greenhouse gas in our atmosphere, CO2 levels have varied widely over the course of the Earth’s 4.54 billion year history.
earth.org
The most distant period in time for which we have estimated CO2 levels is around the Ordovician period, 500 million years ago. At the time, atmospheric CO2 concentration was at a whopping 3000 to 9000 ppm! The average temperature wasn’t much more than 10 degrees C above today’s, and those of you who have heard of the runaway hothouse Earth scenario may wonder why it didn’t happen then. Major factors were that the Sun was cooler, and the planet’s orbital cycles were different.
CO2 levels over the past 500 million years. Foster et al – Descent into the icehouse.
CO2 levels are determined by the imbalance between carbon sequestration (burial in sediments, capture by plants), and carbon emissions (decomposition and volcanic activity). Imbalances in this system created a downward trend in CO2 levels, leading to a glaciation period around 300 million years ago. This was followed by a period of intense volcanic activity, doubling CO2 concentration to about 1000 ppm. Levels then dropped until they reached today’s concentrations during the Oligocene era, 33 to 23 million years ago, when temperatures were still 4 to 6 degrees C higher than today.
So what's your point?A Graphical History of Atmospheric CO2 Levels Over Time | Earth.Org
As the most abundant greenhouse gas in our atmosphere, CO2 levels have varied widely over the course of the Earth’s 4.54 billion year history.
The most distant period in time for which we have estimated CO2 levels is around the Ordovician period, 500 million years ago. At the time, atmospheric CO2 concentration was at a whopping 3000 to 9000 ppm! The average temperature wasn’t much more than 10 degrees C above today’s, and those of you who have heard of the runaway hothouse Earth scenario may wonder why it didn’t happen then. Major factors were that the Sun was cooler, and the planet’s orbital cycles were different.
CO2 levels over the past 500 million years. Foster et al – Descent into the icehouse.
CO2 levels are determined by the imbalance between carbon sequestration (burial in sediments, capture by plants), and carbon emissions (decomposition and volcanic activity). Imbalances in this system created a downward trend in CO2 levels, leading to a glaciation period around 300 million years ago. This was followed by a period of intense volcanic activity, doubling CO2 concentration to about 1000 ppm. Levels then dropped until they reached today’s concentrations during the Oligocene era, 33 to 23 million years ago, when temperatures were still 4 to 6 degrees C higher than today.
jc456
Diamond Member
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To show your error
para bellum
Diamond Member
Islands That Climate Alarmists Said Would Soon “Disappear” Due to Rising Sea Found to Have Grown in Size
An amount of land equivalent to the Isle of Wight has been added to the shorelines of 13,000 islands around the world in just the last 20 years. This fascinating fact of a 369.67 square kilometre increase has recently been discovered by a group of Chinese scientists analysing both surface and satellite records. Overall, land was lost during the 1990s, but the scientists found that in the study period of three decades to 2020 there was a net increase of 157.21 km2. The study observed considerable natural variation in both erosion and accretion. Of course, the findings blow holes in the poster scare run by alarmists suggesting that rising sea levels caused by humans using hydrocarbons will condemn many islands to disappear shortly beneath rising sea levels. By means of such flimsy scare tactics, as we have seen in many other cases, desperate attempts are made to terrify global populations to accept the insanity of the Net Zero collectivisation.
...
A recent study found that the 101 islands of Tuvalu had grown in land mass by 2.9%. The scientists observed that despite rising sea levels, many shorelines in Tuvalu and neighbouring Pacific atolls have maintained relative stability, “without significant alteration”. A comprehensive re-examination of data on 30 Pacific and Indian Ocean atolls with 709 islands found that none of them had lost any land. Furthermore, the scientists added, there are data that indicate 47 reef islands expanded in size or remained stable over the last 50 years, “despite experiencing a rate of sea-level rise that exceeds the global average”.
Islands That Climate Alarmists Said Would Soon "Disappear" Due to Rising Sea Found to Have Grown in Size – The Daily Sceptic
In a fresh blow to climate alarmism, islands like Tuvalu and the Maldives that were predicted soon to "disappear" beneath rising seas have been found to have actually grown in size.
dailysceptic.org
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