As Climate Worsens, a Cascade of Tipping Points Looms

Discussion in 'Environment & Conservation' started by skepticalmike, Dec 15, 2019.

  1. Hoosier8

    Hoosier8 Well-Known Member Past Donor

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    You mean the CO2 centric hypothesis that is isn't falsifiable?
     
  2. Bowerbird

    Bowerbird Well-Known Member

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    Ah! Here we are again with the “I’ll make you go spend hours researching and then dismiss your findings game”

    Not playing to the point where I will only research answers to posts that show research

    Do your own research

    Though I AM tempted to do what many people here do - just make up some numbers
     
  3. Bowerbird

    Bowerbird Well-Known Member

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    And case in point about just making stuff up and not backing what you claim with research
     
  4. AFM

    AFM Well-Known Member Past Donor

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    So you have nothing. You make a claim and can’t back it up.
     
  5. AFM

    AFM Well-Known Member Past Donor

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    I’ve provided references many times previously which you and others have ignored.
     
  6. skepticalmike

    skepticalmike Well-Known Member

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    This is from an article in The Maritime-Executive based on a 2015 article from Science Magazine. I only copied some of it and it only discusses U.S. damage. During the Eemian interglacial period,
    130.000 to 115,000 years ago, temperatures were warmer with lower CO2 levels because the earth's axial tilt was greater than today and other orbital parameters contributed to greater N Hemisphere
    summer insolation. This is evidence that a 1 to 2 degrees C. increase in GMT could result in 20 feet of sea level rise.

    From Wikipedia Eemian interglaicail:

    The Eemian climate is believed to have been a little warmer than the current Holocene.[8][9] Changes in the Earth's orbital parameters from today (greater obliquity and eccentricity, and perihelion), known as Milankovitch cycles, probably led to greater seasonal temperature variations in the Northern Hemisphere.[citation needed] Although global annual mean temperatures were probably several degrees warmer than today, during summer months, temperatures in the Arctic region were about 2-4 °C higher than today.[10] The warmest peak of the Eemian was around 125,000 years ago, when forests reached as far north as North Cape, Norway (which is now tundra) well above the Arctic Circle at 71°10′21″N 25°47′40″E. Hardwood trees such as hazel and oak grew as far north as Oulu, Finland.

    Sea level at peak was probably 6 to 9 metres (20 to 30 feet) higher than today,[17][18] with Greenland contributing 0.6 to 3.5 m (2.0 to 11.5 ft),[19] thermal expansion and mountain glaciers contributing up to 1 m (3.3 ft),[20] and an uncertain contribution from Antarctica.[21] Recent research on marine sediment cores offshore of the West Antarctic Ice Sheet suggest that the sheet melted during the Eemian, and that ocean waters rose as fast as 2.5 meters per century.[22] Global mean sea surface temperatures are thought to have been higher than in the Holocene, but not by enough to explain the rise in sea level through thermal expansion alone, and so melting of polar ice caps must also have occurred.


    https://www.maritime-executive.com/article/scientists-predict-20-foot-sea-level-rise

    When past temperatures were similar to or slightly higher than the present global average, sea levels rose at least 20 feet (six meters), suggesting a similar outcome could be in store if current climate trends
    continue, states a team of scientists after conducting a study led by the U.S.

    The new estimate far exceeds some, such as those made by the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, which predict a rise of over three feet (one meter) by 2100.

    The U.S. findings, published in the journal Science, cite that in the past sea levels rose in response to melting ice sheets in Greenland and Antarctica. Lead author of the study, Andrea Dutton, a University of Florida geochemist, says, “This evidence leads us to conclude that the polar ice sheets are out of equilibrium with the present climate.”

    The researchers concluded that sea levels rose 20 to 30 feet higher than present about 125,000 years ago, when global average temperature was 1°C higher than preindustrial levels (similar to today’s average). Sea level peaked somewhere between 20 and 40 feet above present during an earlier warm period about 400,000 years ago, when global average temperatures are less certain, but estimated to be about 1 to 2°C warmer than the preindustrial average.

    During those times, atmospheric carbon dioxide levels peaked around 280 parts per million, but today’s levels are around 400 ppm and rising. The team of researchers looked at the last time period when carbon dioxide was this high – about three million years ago – but couldn’t get a confident estimate on sea-level rise, in part due to land motion that has distorted the position of past shorelines.

    Climate Central estimates that a 20-foot rise would mean that Florida would lose land that houses more than nine million people, followed by New York, California, Louisiana, Virginia, and New Jersey, each with more than a million people in threatened areas.
     
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  7. Hoosier8

    Hoosier8 Well-Known Member Past Donor

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    There is no disagreement that manmade CO2 has increased the level but the reason the CO2 level is so low is that we have been in a 2.5 million year ice age. Increasing CO2 is beneficial and as you have pointed out, warmer temperatures did not correlate with CO2.
     
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  8. yguy

    yguy Well-Known Member

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    Well that'll sure work out swell for the "scientists" making such predictions, seeing they'll have collected their pensions by the time those predictions prove to be bogus - not that anyone will remember by then anyway.
     
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  9. william kurps

    william kurps Banned

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    In simple terms the C02 level was five times higher then today during the Jurasic era and plants and animals grew huge.
     
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  10. AFM

    AFM Well-Known Member Past Donor

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    Yes. The idea that these computer models can predict accurately anything more than three years into the future is ridiculous.
     
  11. ARDY

    ARDY Well-Known Member Past Donor

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    limo, this will happen gradually, and we will adapt

    That said, the worst impacts will be in places where large numbers of poor people live on flood plains that are even now barely above sea level... ie bangladesh. These are people who cannot afford to relocate and would have no place to relocate to.

    such places will also face severe fresh water shortages as mountain glaciers disappear. They will not be able to afford desalination plants to replace that water supply.

    such places can already become oppressively hot at current temperatures. It is a bit difficult to imagine what living there will be like if there are significant temperature increases

    but, these are not problems to concern us, I guess. We will be able to re locate; we will build desalination plants; we will buy air conditioning... so I think we will be ok
     
  12. ARDY

    ARDY Well-Known Member Past Donor

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    fwiw, these natural adaptations evolved over geologic time scales. The potential changes that are being discussed will happen over a dramatically shorter time frame... a few hundred years
     
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  13. AFM

    AFM Well-Known Member Past Donor

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    The Bangladesh concern is a joke. The real problem is the the amount of silt which continually replenished the river delta has been severely reduced due to dam construction. That has nothing to do with global warming.
     
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  14. AFM

    AFM Well-Known Member Past Donor

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    The majority of the previous 9 warming periods of the Holocene warmed at greater rates and resulted higher temperatures than we are experiencing today. And with no change in CO2.
     
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  15. william kurps

    william kurps Banned

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    The great Sahara desert went from tropical to dry in only a few hundred years for example, no fossil fuel no great deforestation.

    A few interesting debates on this, one of them


    https://www.upi.com/Science_News/2016/11/30/How-did-the-Sahara-Desert-get-so-dry/1221480539480/


    How did the Sahara Desert get so dry?
    "It has been something of a mystery to understand how the tropical rain belt moved so far north of the equator," researcher Robert Korty said.
     
    Last edited: Dec 19, 2019
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  16. Bowerbird

    Bowerbird Well-Known Member

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    Where?

    Did they “grow huge” at the tropics?

    What was the solar output during the Jurassic

    BTW you seem to have missed backing your claim with a citation from a relevant source
     
  17. Bowerbird

    Bowerbird Well-Known Member

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    Glory be a citation!

    You DO realise don’t you that this research (original is here https://www.nature.com/articles/ngeo2833) would have used proxy data to confirm the hypothesis?
     
  18. Bowerbird

    Bowerbird Well-Known Member

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    Whhhops! Forgot your citation old chap!
     
  19. william kurps

    william kurps Banned

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    To say the earth hasn't changed before is preposterous, humans evolved at the perfect time

    More variables? One is answering it's own question.

    I am getting bored with common knowledge how big plants and animals where during the dino periods.

    Live Science › 44330-jurassic-di...
    Web results
    Dinosaur Era Had 5 Times Today's CO2 | Live Science

    Mar 24, 2014 · Dinosaurs that roamed the Earth 250 million years ago knew a world with five times more carbon dioxide than is present on Earth today, researchers say, and new techniques for estimating the amount of carbon dioxide on prehistoric Earth may help scientists predict how Earth's climate may change in the future
     
  20. Bowerbird

    Bowerbird Well-Known Member

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    Citation????
     
  21. william kurps

    william kurps Banned

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    It was core samples of ocean dirt, not proxy temperature data..


    https://www.google.com/amp/s/www.livescience.com/amp/28493-when-sahara-desert-formed.html



     
  22. Bowerbird

    Bowerbird Well-Known Member

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    Who is saying it hasn’t changed before? Not me! Just want accuracy in statements - make a claim back it up
    Yes they are called “forcings”.

    Again - what was the solar output? Where was earth in the Milankovitch cycle? What was the amount of volcanic activity - volcanoes can both cool and heat (https://scied.ucar.edu/shortcontent/how-volcanoes-influence-climate) What was the Albee’s of the planet? What oceanic currents were there and where did they flow?

    I am getting bored with common knowledge how big plants and animals where during the dino periods.

    Live Science › 44330-jurassic-di...
    Web results
    Dinosaur Era Had 5 Times Today's CO2 | Live Science

    Mar 24, 2014 · Dinosaurs that roamed the Earth 250 million years ago knew a world with five times more carbon dioxide than is present on Earth today, researchers say, and new techniques for estimating the amount of carbon dioxide on prehistoric Earth may help scientists predict how Earth's climate may change in the future[/QUOTE]
    You do realise this is proxy measurement right?
     
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  23. Bowerbird

    Bowerbird Well-Known Member

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  24. AFM

    AFM Well-Known Member Past Donor

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    Given them times.
     
  25. AFM

    AFM Well-Known Member Past Donor

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    Given it many times.
     

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