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Climate warming will bring the Earth to an unprecedented 420 million year high

During the next tens and hundreds of years, carbon dioxide concentrations in the Earth's atmosphere will reach values ​​not seen since the Triassic period, 200 million years ago. Furthermore, in the 23rd century, the climate may reach temperatures not seen in 420 million years, the researchers say.

Live (left) and fossilized ginkgo leaf (right). The density of piones in such leaves provides an approximation of the atmospheric CO2 concentration in the past. Photo: Dana Royer, courtesy of the University of Southampton.
Live (left) and fossilized ginkgo leaf (right). The density of piones in such leaves provides an approximation of the atmospheric CO2 concentration in the past. Photo: Dana Royer, courtesy of the University of Southampton.

A new study led by researchers from the University of Southampton estimates that during the next 100-200 years, carbon dioxide concentrations in the Earth's atmosphere will reach values ​​not seen since the Triassic period, 200 million years ago. Furthermore, by the 23rd century, the climate could reach record temperatures not seen in 420 million years.

The study, published in Nature Communications, included more than 1,200 estimates of ancient atmospheric carbon dioxide concentrations to produce a continuous record and reconstruct the levels of this gas over nearly half a billion years. If humanity continues to burn all existing fossil fuels, carbon dioxide levels in the atmosphere will reach an almost geologically unprecedented high in 420 million years.

The researchers examined data published in previous studies on fossil plants, the isotopic composition of carbon in soil and oceans, and the isotopic composition of boron in fossil shells. Gavin Foster, lead author and professor of isotope geochemistry at the University of Southampton, explains: "CO2 concentrations from millions of years ago cannot be directly measured, but we rely on other measurements that give us an indirect estimate. All the published data from several types of such approximations allowed us to create a continuous record of CO2 levels in ancient times."

The wealth of data shows that carbon dioxide concentrations have varied on a scale of millions of years from 200 to 400 parts per million during cold periods and up to 3,000 during warm periods. Although the evidence tells us that our climate has changed a lot in the past, when the Earth is now in a relatively cold period, it also shows us that the speed of climate change is extremely extraordinary.

Carbon dioxide is a significant greenhouse gas. In the last 150 years, humanity's use of fossil fuels has increased its atmospheric concentration from 280 parts per million in the pre-industrial era to nearly 405 parts per million in 2016. However, it is not just CO2 that determines our planet's climate, ultimately its power of the greenhouse effect and also the amount of incoming light is important. Changes in both parameters are capable of forcing climate change.

"Due to nuclear reactions in stars, like our Sun, over time they become brighter," adds another author of the paper Dan Lent, professor of climate science at the University of Bristol. "This means that although carbon dioxide concentrations were high hundreds of millions of years ago, the net warming effect of CO2 and sunlight was less, the CO2 level showed a gradual decrease of 3-4 parts per million. This may not sound like a lot, but it is actually enough to cancel out the warming effect caused by the sun over time, so in the long run the net effect of both was fairly constant on average. "

This interplay between carbon dioxide and the brightness of the sun has fascinating implications for the history of life on Earth. Says Prof. Dana Royer, from Wesleyan University in the USA: "Until now it has been a bit of a puzzle why, despite the sun's output slowly increasing over time, there is similar evidence for a similar range of climate warming. Our finding of a small change in the net climate change offers an explanation as to why the Earth's climate has remained relatively stable, and in an area suitable for life for all this time."

This long-term view provides a valuable perspective on the future climate. She also recognizes that today's climate is changing at much higher rates than natural changes. If humanity does not stop increasing the concentration of carbon dioxide due to the burning of fossil fuels, by the year 2250 the concentration of carbon dioxide will reach 2000 parts per million, 5 times more than today, a level not seen for 200 million years.

Prof. Foster adds: "However, because the sun was then dimmer, the net climate 200 million years ago was colder than that which will occur in the future with such a high concentration of CO2, so not only is the resulting climate change faster than anything on Earth as Seen in millions of years, the resulting climate may be without a natural counterpart, as far as we can tell, at least in the last 420 million years."

to the notice of the researchers

10 תגובות

  1. my father
    If you insist on bringing all the opinions, even those outside the consensus, you have to bring the opinion that global warming is due to the overactivity of Phaistos - the blacksmith god who causes increased activity of volcanoes in order to punish the humans who abandoned the gods of Olympus.
    There is a reason that the scientific consensus is that climate change is accelerating due to human activity.
    The reason is not fear of scientists to express an opposing opinion for fear that they will stop funding them and inviting them to parties.
    The reason is that the evidence (which is open and accessible to everyone) shows that there is a definite causality between human activity and the climate.
    The reason the opponents of science want equality between all opinions is that they want to reduce the weight of opinions that do not fit their beliefs.
    There is a difference between an opinion based on evidence and an opinion that ignores it.

  2. Avi - the article you brought supports human-made warming:
    "The concentrations of these gases in the atmosphere have increased in recent centuries at a much greater rate than before man began to cut down forests and burn coal and other fuels intensively"

  3. Funny - that I posted a link to the topic of the Ice of the Witness, precisely here in the 2005 study.
    In any case, I just wanted to point out that from these studies and perhaps others similar to them, different scientists reached different and opposite conclusions, it all depends on how you look at it.
    Just to make it clear that I am not against the theory that claims that global warming is man-made, and not against the need to fight greenhouse gases and air pollution in general - I am actually very much in favor of it.
    But I am also of the opinion that it is appropriate on a scientific website to present things as scientifically and objectively as possible, and to show all sides and all opinions, even those that are against the consensus.

  4. For miracles:
    This article was published more than a decade ago, so I don't have the link at the moment, I will look for a link when I get the chance.
    In the polar regions, it snows in the winter and a pile of snow accumulates, and in the summer the snow melts and freezes, then there are crisp layers of winter and hard layers of summer, so you can literally count the years like the rings of a tree. Inside the ice, samples are trapped in the air.
    Scientists drilled into the witness ice at the Pole and brought out sausages of ice from great depths.
    The drillings in the witness ice showed that the ice in the pole is trapped in air in bubbles that make it possible to check the composition of the air while it is being formed.
    Graphs of the carbon dioxide concentrations in the air over millions of years were obtained from the measurements. They showed that there is naturally a cycle of increases and decreases in this concentration parallel to the thickness of the ice layers of that period. You can see if it was an ice age or a warm period.
    There are of course debates about the conclusions of these studies, whether the current increase is the same as the increases in the past or different from them, and whether it is due to humans or not...
    In any case, I don't want to have a debate for and against global warming, but to express surprise at what is written above quote: "The researchers examined data published in previous studies on fossilized plants, the isotopic composition of carbon in the soil and oceans, and the isotopic composition of boron in fossilized shells..."
    And this without even mentioning the studies carried out on the polar ice cap.

  5. my father
    Can I have a link to your article please?
    I would also like to understand from you how the article shows that man is not the cause of warming.

  6. In another study I read by a group of scientists who oppose the theory that global warming is a man-made act, it is actually possible to find air from millions of years ago and directly measure the amount of CO2 that was in the air millions of years ago.
    The researchers found air trapped in layers of ice in drillings made at the Earth's poles and directly measured the concentration of carbon dioxide in this air.
    The dating of the periods is also very easy with these drillings because in the summer there is a layer of snow and in the winter there is a denser layer and therefore rings are formed in the ice like a tree and you can count the years exactly, without having to use inaccurate dating methods.
    It is amazing that the honorable professor does not know about this.
    Actually, maybe it's not surprising, because the findings of the same group of scientists who drilled at the poles are that man does not affect global warming and there is such a cycle of warming and cooling in a natural way...

  7. Within 50 years at most all electricity would be produced from the sun or other renewable means. Already today tenders were closed at 20 cents per kilowatt hour for solar energy. In a few years there will be studies that will increase the efficiency to 50-60 percent and it will be possible to generate electricity for 10 cents and then it will not be profitable to build any power station except for solar fields. Another advantage that is achieved is the decentralization of the system. There will be so many diesel fields that no local damage will shut down the electricity sector in the country. Countries like Jordan could be exporters of electricity and in general electricity will become so cheap and clean that the entire global production system will change. Cars, desalinated water, everything will work on cheap and clean electricity. The lack economy that we have been in since humans took over the earth will disappear and we will move to a real abundance economy.

  8. Links to the science article on plankton. If plankton is responsible for 50 percent of the oxygen in the Earth, and there is 75% of the ocean, then why not sow chloroplastic plankton. It's better than the somewhat lost battle in the rainforest. It is possible that then another balance will be disturbed and the fields we have seeded will get out of control and cause other damage to the fish, or the fish will eat the plankton.

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