3 ms·

> My evidence for this is that in the vast span of human history before these things existed, neither did climate change! We are currently in the Holocene. Do

> My evidence for this is that in the vast span of human history before these things existed, neither did climate change! We are currently in the Holocene. Do you know what that means? Have a look at this temperature graph and you might get an inkling of the changing climate: https://en.wikipedia.org/wiki/Holocene#/media/File:Holocene_Temperature_Variations.png https://en.wikipedia.org/wiki/Holocene#/media/File:Holocene_... Realise that this graph only shows the interglacial period (Holocene), not what things looked like during the Pleistocene (the last glacial period) or the Younger Dryas. For a more expansive overview have a look at this graph: https://upload.wikimedia.org/wikipedia/commons/6/63/Evolution_of_temperature_in_the_Post-Glacial_period_according_to_Greenland_ice_cores_%28Younger_Dryas%29.jpg https://upload.wikimedia.org/wikipedia/commons/6/63/Evolutio...

sigmoid10 4y ago
Temperature variations in ancient times are very unreliable, because they can only be inferred indirectly. The big giveaway for anthropogenic climate change is co2 concentration, since we can directly measure its value hundreds of thousands of years in the past thanks to air bubbles enclosed deep in glaciers: https://climate.nasa.gov/climate_resources/24/graphic-the-relentless-rise-of-carbon-dioxide/ https://climate.nasa.gov/climate_resources/24/graphic-the-re... It clearly shows that the atmosphere never looked anything like this since humans climbed down from trees. Bonus fact: All mass extinctions happened when the co2 levels rose over a certain value (we're already at 419ppm, that 393ppm value in the article is from a few years ago): https://johnenglander.net/co2-levels-and-mass-extinction-events/ https://johnenglander.net/co2-levels-and-mass-extinction-eve... If they rise over 600ppm for example, the oceans will acidify and their ecosystems will collapse. Since most of our oxygen comes from oceanic plankton, we'll literally suffocate when that happens - and at the current trend it could happen before the century is over. The largest extinction event ever, the Permian-Triassic event (where 80% of marine life and 70% of terrestrial vertebrates died), is currently thought to have been caused by massive emissions of runaway greenhouse gases in the thawing Siberian tundra - similar to what we are seeing right now.
- foverzar 4y ago
  > Temperature variations in ancient times are very unreliable, because they can only be inferred indirectly > The big giveaway for anthropogenic climate change is co2 concentration, since we can directly measure its value hundreds of thousands of years in the past thanks to air bubbles enclosed deep in glaciers I can't believe that these two are consecutive sentences. Are you manipulating the meaning of "direct measurement" on purpose? You can't really get a direct measurement of something from the past without a time machine. Glaciers are, by definition, an indirect measurement, that relies on a specific model to calculate the measurement value. There is a lot of criticism of this model from chemists, but since it is no longer a scientific discussion, but a political one, these people typically get repressed.
  - Kim_Bruning 4y ago
    Do you have links to papers on this?
VBprogrammer 4y ago
> We are currently in the Holocene. Do you know what that means? I don't think it means anything. It is the entire period from the last ice-age until present encompassing the entirety of recorded history? What do you think it means?
- the_third_wave 4y ago
  Instead of explaining I'll just add a link to one of those Wikipedia pages which still seems to be free from ideological bias: https://en.wikipedia.org/wiki/Holocene https://en.wikipedia.org/wiki/Holocene The key thing to look for is this: The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial. It is not 'the entire period from the last ice-age until present' because we're still in an ice age. The Holocene is the current interglacial period, before it came the Younger Dryas, what comes after it is of course as of yet unknown but given the way previous interglacials came and went it is likely to be followed by a long period of glaciation. The main takeaway is that the climate has been changing ever since the planet developed and will keep on doing so until there is no more atmosphere, i.e. when the sun blows up to encompass the orbit of Venus and strips the Earth's atmosphere off. That'll take a while so it is not necessary to start planning for this scenario. It was changing when Homo Sapiens developed some 300.000 years ago, it was changing when our species moved out of Africa - who knows, this might even have played a role in that migration. Homo Sapiens was there when a large part of the northern hemisphere was covered in land ice, 'we' were there when that ice retreated. We survived then, we will survive now.

sigmoid10 4y ago

Temperature variations in ancient times are very unreliable, because they can only be inferred indirectly. The big giveaway for anthropogenic climate change is co2 concentration, since we can directly measure its value hundreds of thousands of years in the past thanks to air bubbles enclosed deep in glaciers: https://climate.nasa.gov/climate_resources/24/graphic-the-relentless-rise-of-carbon-dioxide/ https://climate.nasa.gov/climate_resources/24/graphic-the-re... It clearly shows that the atmosphere never looked anything like this since humans climbed down from trees. Bonus fact: All mass extinctions happened when the co2 levels rose over a certain value (we're already at 419ppm, that 393ppm value in the article is from a few years ago): https://johnenglander.net/co2-levels-and-mass-extinction-events/ https://johnenglander.net/co2-levels-and-mass-extinction-eve... If they rise over 600ppm for example, the oceans will acidify and their ecosystems will collapse. Since most of our oxygen comes from oceanic plankton, we'll literally suffocate when that happens - and at the current trend it could happen before the century is over. The largest extinction event ever, the Permian-Triassic event (where 80% of marine life and 70% of terrestrial vertebrates died), is currently thought to have been caused by massive emissions of runaway greenhouse gases in the thawing Siberian tundra - similar to what we are seeing right now.

foverzar 4y ago
> Temperature variations in ancient times are very unreliable, because they can only be inferred indirectly > The big giveaway for anthropogenic climate change is co2 concentration, since we can directly measure its value hundreds of thousands of years in the past thanks to air bubbles enclosed deep in glaciers I can't believe that these two are consecutive sentences. Are you manipulating the meaning of "direct measurement" on purpose? You can't really get a direct measurement of something from the past without a time machine. Glaciers are, by definition, an indirect measurement, that relies on a specific model to calculate the measurement value. There is a lot of criticism of this model from chemists, but since it is no longer a scientific discussion, but a political one, these people typically get repressed.
- Kim_Bruning 4y ago
  Do you have links to papers on this?

VBprogrammer 4y ago

> We are currently in the Holocene. Do you know what that means? I don't think it means anything. It is the entire period from the last ice-age until present encompassing the entirety of recorded history? What do you think it means?

the_third_wave 4y ago
Instead of explaining I'll just add a link to one of those Wikipedia pages which still seems to be free from ideological bias: https://en.wikipedia.org/wiki/Holocene https://en.wikipedia.org/wiki/Holocene The key thing to look for is this: The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch, called the Flandrian interglacial. It is not 'the entire period from the last ice-age until present' because we're still in an ice age. The Holocene is the current interglacial period, before it came the Younger Dryas, what comes after it is of course as of yet unknown but given the way previous interglacials came and went it is likely to be followed by a long period of glaciation. The main takeaway is that the climate has been changing ever since the planet developed and will keep on doing so until there is no more atmosphere, i.e. when the sun blows up to encompass the orbit of Venus and strips the Earth's atmosphere off. That'll take a while so it is not necessary to start planning for this scenario. It was changing when Homo Sapiens developed some 300.000 years ago, it was changing when our species moved out of Africa - who knows, this might even have played a role in that migration. Homo Sapiens was there when a large part of the northern hemisphere was covered in land ice, 'we' were there when that ice retreated. We survived then, we will survive now.