4 ms·

https://en.m.wikipedia.org/wiki/List_of_periods_and_events_in_climate_history https://en.m.wikipedia.org/wiki/List_of_periods_and_events_i... 'List of periods a

https://en.m.wikipedia.org/wiki/List_of_periods_and_events_in_climate_history https://en.m.wikipedia.org/wiki/List_of_periods_and_events_i... 'List of periods and events in climate history'

chrisco255 7y ago
These are very interesting. They do not get covered very often, but these events show climate changes in precipitation and temperature occur on the regular and cause even dramatic events (like the drying of the Sahara) naturally. I'm still trying to piece together what impacts geomagnetic excursions and reversals have on climate. During the last reversal 780,000 years ago the winter Asian monsoon was about 3x stronger than today according to one study I read.
- KnightOfWords 7y ago
  Historical civilisations were very vulnerable to changes in local climate as they were heavily reliant on local food production, whereas we routinely ship food across oceans. Events like the [Little Ice Age](https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age) barely show up in the global climate record. Earth's climate has varied greatly over time but its the current rate of change that is so alarming. During the last ice age it was about 4.5 degrees colder but it took 10,000 years to reach modern temperatures. We're currently on a path to changes of that magnitude within the next 70-100 years.
  - chrisco255 7y ago
    You're incorrect about your assumptions. If you click the link in the parent post, you'll see that temperatures swung as much as 8C during the ice age. These events are called Dansgaard-Oeschger events (https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_event https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_eve...) The warming would happen rapidly (within 3 decades), followed by a stepped down cooling period (often lasting hundreds of years). This happened repeatedly during the most recent glacial. And then more recently, after the last glacial period had ended, you had incidents like the Younger Dryas, for example, where temps plunged to near ice age levels (up to 6C drop in a few decades) and then rapidly warmed all of a sudden. If you read https://en.wikipedia.org/wiki/Younger_Dryas https://en.wikipedia.org/wiki/Younger_Dryas) some are suggesting that a warming episode at the end of the Younger Dryas occurred in as little as a few years and warmed global temps by 7C. Note, that by the end of the Younger Dryas, the Arctic was as much as 7C hotter than it is today (https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084384?fbclid=IwAR38AO0dy7knA42dkG7UgTHLlL8H0la2iFYd2k1uqNyp7h7Ny2t61L0x42o https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019...). There's thousands of papers on the Little Ice Age. It certainly shows up all over the world in the fossil record. https://www.sciencedirect.com/search/advanced?qs=little%20ice%20age https://www.sciencedirect.com/search/advanced?qs=little%20ic...
    - antocv 7y ago
      Thats why I hate these Greta style "climate activists", since they only focus on climate, as if thats the only bad shit going on concerning environment. And even so, they are wrong about "apocalypse" style of events. Even if you solve atmospheric conditions, CO2 and temperature, still you have the pollution of the waters, mass extinctions due to habitat loss, car-tyres rubbering off everywhere, unknown untested toxins even on your cloths. Thats like, not talked about. EDIT: Cant believe somebody downvoted you. Yes nature has done fast changes, faster than human-induced change currently, and "nature" has mass-exterminated most of its life several times over, and other forms of life caused the deaths and biological disaster for most of other life on earth as well. These are facts. Somehow these Greata climate activists, would like to believe that humans are more powerful in their destruction than cyanobacteria. Wishful thinking really.
      - saagarjha 7y ago
        What makes you think she doesn’t care about other aspects of the environment? She’s just focusing on climate change because it has an effect on all of those things too.
        roenxi 7y ago
        The currently vocal environmentalist movement started from the left and picked up a lot more in the way of anti-capitalist sentiment, strong overtones of guilt and a real push to undertake acts of repentance and sacrifice. Their focus has pronounced overtones of repentance for our sins against the environment and has some very classically Christian themes. Things like the 'how dare you' comment to the UN help brand her as part of that specific branch of the environmentalist movement. She may personally care about who knows what, but the phenomenon that she looks to represent is a specific branch of environmentalism that is pushing different agenda to general environmental concerns. The environment-should-serve-humans-and-be-managed-to-do-so style environmentalists that used to be present in Australian right-wing politics have all but disappeared as the environmental issues they cared about are drowned out by people like Greta. I expect that has happened elsewhere too, and it is very easy to imagine that they don't see people like Greta as representing the environmental conservation issues they care about. The rather important concepts of practical sustainable living are drowned out by apocalyptic doomsayers who imply that the environmental costs of the rise of China and India are too great. Which just isn't going to gain traction, China and India represent 35% of the worlds population. We aren't going to give the environment some sort of primacy over the material comfort of 35% of the worlds population. People first, environment second. (My favourite graph at present: https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita#/media/File:2018_AQAL_Group_variwide_chart_%22Worldwide_Co2_emissions%22.jpg https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di... )
  - bregma 7y ago
    There's a good deal of observation bias at play here. We currently track the "average annual daily global mean temperature" to somewhere around 4 digits of precision, with an accuracy of around 3 digits of precision (back in the day my university TAs would fail any lab report with inverse precision like that, but I'm no PhD in climate science), and with a time frame of hours. Estimated historic temperatures are presented with 2 or 3 digits of precision over a timeframe of centuries or kiloyears. Saying current trends are unprecedented is motivational and technically correct, but not scientifically sound given the actual data. Well, science as in hard sciences like chemistry and physics in which we could run controlled experiments to generate confidence in our understanding; not soft sciences like economics or nutrition where controlled experiments would be unethical and results are only as good as the next product you're selling. My point is that you can see the current short-term trends because we have precision and accuracy to be able to do that. We lack the precision and accuracy of historical data to be able to do that, which makes it an argumentum ad ignorantiam.
cbanek 7y ago
I love learning about past Earth climate history and just history in general. One of my mind blowing climate events is: https://en.wikipedia.org/wiki/Messinian_salinity_crisis https://en.wikipedia.org/wiki/Messinian_salinity_crisis It's not in the list you link, but it's a pretty neat read. Basically, the Mediterranean dried up and refilled about 6 million years ago.
- mkl 7y ago
  And it's five kilometres deep.
- Symmetry 7y ago
  One of the best XKCDs ever is sort of related: https://www.explainxkcd.com/wiki/index.php/1190:_Time https://www.explainxkcd.com/wiki/index.php/1190:_Time

https://en.m.wikipedia.org/wiki/List_of_periods_and_events_in_climate_history https://en.m.wikipedia.org/wiki/List_of_periods_and_events_i... 'List of periods and events in climate history'

chrisco255 7y ago

These are very interesting. They do not get covered very often, but these events show climate changes in precipitation and temperature occur on the regular and cause even dramatic events (like the drying of the Sahara) naturally. I'm still trying to piece together what impacts geomagnetic excursions and reversals have on climate. During the last reversal 780,000 years ago the winter Asian monsoon was about 3x stronger than today according to one study I read.

KnightOfWords 7y ago
Historical civilisations were very vulnerable to changes in local climate as they were heavily reliant on local food production, whereas we routinely ship food across oceans. Events like the [Little Ice Age](https://en.wikipedia.org/wiki/Little_Ice_Age https://en.wikipedia.org/wiki/Little_Ice_Age) barely show up in the global climate record. Earth's climate has varied greatly over time but its the current rate of change that is so alarming. During the last ice age it was about 4.5 degrees colder but it took 10,000 years to reach modern temperatures. We're currently on a path to changes of that magnitude within the next 70-100 years.
- chrisco255 7y ago
  You're incorrect about your assumptions. If you click the link in the parent post, you'll see that temperatures swung as much as 8C during the ice age. These events are called Dansgaard-Oeschger events (https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_event https://en.wikipedia.org/wiki/Dansgaard%E2%80%93Oeschger_eve...) The warming would happen rapidly (within 3 decades), followed by a stepped down cooling period (often lasting hundreds of years). This happened repeatedly during the most recent glacial. And then more recently, after the last glacial period had ended, you had incidents like the Younger Dryas, for example, where temps plunged to near ice age levels (up to 6C drop in a few decades) and then rapidly warmed all of a sudden. If you read https://en.wikipedia.org/wiki/Younger_Dryas https://en.wikipedia.org/wiki/Younger_Dryas) some are suggesting that a warming episode at the end of the Younger Dryas occurred in as little as a few years and warmed global temps by 7C. Note, that by the end of the Younger Dryas, the Arctic was as much as 7C hotter than it is today (https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019GL084384?fbclid=IwAR38AO0dy7knA42dkG7UgTHLlL8H0la2iFYd2k1uqNyp7h7Ny2t61L0x42o https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2019...). There's thousands of papers on the Little Ice Age. It certainly shows up all over the world in the fossil record. https://www.sciencedirect.com/search/advanced?qs=little%20ice%20age https://www.sciencedirect.com/search/advanced?qs=little%20ic...
  - antocv 7y ago
    Thats why I hate these Greta style "climate activists", since they only focus on climate, as if thats the only bad shit going on concerning environment. And even so, they are wrong about "apocalypse" style of events. Even if you solve atmospheric conditions, CO2 and temperature, still you have the pollution of the waters, mass extinctions due to habitat loss, car-tyres rubbering off everywhere, unknown untested toxins even on your cloths. Thats like, not talked about. EDIT: Cant believe somebody downvoted you. Yes nature has done fast changes, faster than human-induced change currently, and "nature" has mass-exterminated most of its life several times over, and other forms of life caused the deaths and biological disaster for most of other life on earth as well. These are facts. Somehow these Greata climate activists, would like to believe that humans are more powerful in their destruction than cyanobacteria. Wishful thinking really.
    - saagarjha 7y ago
      What makes you think she doesn’t care about other aspects of the environment? She’s just focusing on climate change because it has an effect on all of those things too.
      - roenxi 7y ago
        The currently vocal environmentalist movement started from the left and picked up a lot more in the way of anti-capitalist sentiment, strong overtones of guilt and a real push to undertake acts of repentance and sacrifice. Their focus has pronounced overtones of repentance for our sins against the environment and has some very classically Christian themes. Things like the 'how dare you' comment to the UN help brand her as part of that specific branch of the environmentalist movement. She may personally care about who knows what, but the phenomenon that she looks to represent is a specific branch of environmentalism that is pushing different agenda to general environmental concerns. The environment-should-serve-humans-and-be-managed-to-do-so style environmentalists that used to be present in Australian right-wing politics have all but disappeared as the environmental issues they cared about are drowned out by people like Greta. I expect that has happened elsewhere too, and it is very easy to imagine that they don't see people like Greta as representing the environmental conservation issues they care about. The rather important concepts of practical sustainable living are drowned out by apocalyptic doomsayers who imply that the environmental costs of the rise of China and India are too great. Which just isn't going to gain traction, China and India represent 35% of the worlds population. We aren't going to give the environment some sort of primacy over the material comfort of 35% of the worlds population. People first, environment second. (My favourite graph at present: https://en.wikipedia.org/wiki/List_of_countries_by_carbon_dioxide_emissions_per_capita#/media/File:2018_AQAL_Group_variwide_chart_%22Worldwide_Co2_emissions%22.jpg https://en.wikipedia.org/wiki/List_of_countries_by_carbon_di... )
- bregma 7y ago
  There's a good deal of observation bias at play here. We currently track the "average annual daily global mean temperature" to somewhere around 4 digits of precision, with an accuracy of around 3 digits of precision (back in the day my university TAs would fail any lab report with inverse precision like that, but I'm no PhD in climate science), and with a time frame of hours. Estimated historic temperatures are presented with 2 or 3 digits of precision over a timeframe of centuries or kiloyears. Saying current trends are unprecedented is motivational and technically correct, but not scientifically sound given the actual data. Well, science as in hard sciences like chemistry and physics in which we could run controlled experiments to generate confidence in our understanding; not soft sciences like economics or nutrition where controlled experiments would be unethical and results are only as good as the next product you're selling. My point is that you can see the current short-term trends because we have precision and accuracy to be able to do that. We lack the precision and accuracy of historical data to be able to do that, which makes it an argumentum ad ignorantiam.

cbanek 7y ago

I love learning about past Earth climate history and just history in general. One of my mind blowing climate events is: https://en.wikipedia.org/wiki/Messinian_salinity_crisis https://en.wikipedia.org/wiki/Messinian_salinity_crisis It's not in the list you link, but it's a pretty neat read. Basically, the Mediterranean dried up and refilled about 6 million years ago.

mkl 7y ago
And it's five kilometres deep.
Symmetry 7y ago
One of the best XKCDs ever is sort of related: https://www.explainxkcd.com/wiki/index.php/1190:_Time https://www.explainxkcd.com/wiki/index.php/1190:_Time