4 ms·

> An ice age is simply when the earth's poles have an ice cover. Are you sure? I'm not seeing that definition anywhere, and it looks like even in interglacial

by jefftk 2y ago

> An ice age is simply when the earth's poles have an ice cover. Are you sure? I'm not seeing that definition anywhere, and it looks like even in interglacial periods there's permanent ice in both hemispheres: https://en.wikipedia.org/wiki/Ice_age#Glacials_and_interglacials https://en.wikipedia.org/wiki/Ice_age#Glacials_and_interglac...

johnnyjeans 2y ago
Interglacial periods are a part of ice ages. Even tells you right at the beginning of that article. > Individual pulses of cold climate within an ice age are termed glacial periods (glacials, glaciations, glacial stages, stadials, stades, or colloquially, ice ages), and intermittent warm periods within an ice age are called interglacials or interstadials. You can actually see the definition (albeit a little verbose) as the first sentence of that article: > An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. On a technicality, you can get me for not mentioning the snow capped mountains part, I'd concede on that. That part is actually news to me. All the same, the earth is colder than it usually is. [1] An interesting thing I like to bounce around in my head: Could we live in the interior of the Pangean super continent if we had to? Interesting stepping stone between Earth's current, very mild climate, and trying to live in a place like Venus. Definitely would have to live like mole people. [1] - https://www.climate.gov/media/11332 https://www.climate.gov/media/11332
- jefftk 2y ago
  Mmm, looks like you're right. Sorry!
  - johnnyjeans 2y ago
    No worries. It's not commonly known! For as important as it's become to talk about the climate, the brass tacks remain pretty esoteric.
- nine_k 2y ago
  > Could we live in the interior of the Pangean super continent We already avoid living in the interior of Australia, because living at temperatures of +50°C is just not very compatible with having body temperature slightly below +37°C. Same applies to the middle of Sahara desert. It's not impossible though, because the humidity is very low there, so, given a supply of water, you can cool by evaporation. At high humidity. you'd just die; such things happen during heat waves on the Indian subcontinent, for example.
  - samatman 2y ago
    People certainly die during heat waves, on the Subcontinent and elsewhere. High heat at high humidity is dangerous to endure. However, there is no historical record of the wet bulb temperature outdoors exceeding human body temperature, anywhere, ever. So far. Which is what it would take for the human body to be unable to remove excess heat in any fashion.
    - ordinaryradical 2y ago
      See also: chapter one of Kim Stanley Robinson’s The Ministry for the Future.
    - relaxing 2y ago
      > However, there is no historical record of the wet bulb temperature outdoors That’s not really saying much. The historical record is vanishingly small.
    - gaadd33 2y ago
      The current record of 36.6 seems like it would be close enough to cause major issues.
- tbrownaw 2y ago
  > Individual pulses of cold climate within an ice age are termed [...] ([...] or colloquially, ice ages), Looks like both sides are right in this case.
nosianu 2y ago
I will not argue about definitions of terms, but there was a recent study that I found linked on washingtonpost.com I believe (Edit: found, added). WP article: https://www.washingtonpost.com/climate-environment/2024/09/19/earth-temperature-global-warming-planet/ https://www.washingtonpost.com/climate-environment/2024/09/1... (https://archive.md/RM8ez https://archive.md/RM8ez) > ...humans evolved during the coldest epoch of the Phanerozoic [the time period from 540 million years ago to the present], when global average temperatures were as low as 51.8 F (11 C). > “We built our civilization around those geologic landscapes of an icehouse,” Judd [one of the study's authors] said. Study (restricted): "A 485-million-year history of Earth’s surface temperature" -- https://www.science.org/doi/10.1126/science.adk3705 https://www.science.org/doi/10.1126/science.adk3705 > Partitioning the reconstruction into climate states indicates that more time was spent in warmer rather than colder climates Look at the graph - our time is on the very right. We humans developed and are still living in unusually cold times for this planet, historically.

by jefftk 2y ago

johnnyjeans 2y ago

Interglacial periods are a part of ice ages. Even tells you right at the beginning of that article. > Individual pulses of cold climate within an ice age are termed glacial periods (glacials, glaciations, glacial stages, stadials, stades, or colloquially, ice ages), and intermittent warm periods within an ice age are called interglacials or interstadials. You can actually see the definition (albeit a little verbose) as the first sentence of that article: > An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. On a technicality, you can get me for not mentioning the snow capped mountains part, I'd concede on that. That part is actually news to me. All the same, the earth is colder than it usually is. [1] An interesting thing I like to bounce around in my head: Could we live in the interior of the Pangean super continent if we had to? Interesting stepping stone between Earth's current, very mild climate, and trying to live in a place like Venus. Definitely would have to live like mole people. [1] - https://www.climate.gov/media/11332 https://www.climate.gov/media/11332

jefftk 2y ago
Mmm, looks like you're right. Sorry!
- johnnyjeans 2y ago
  No worries. It's not commonly known! For as important as it's become to talk about the climate, the brass tacks remain pretty esoteric.
nine_k 2y ago
> Could we live in the interior of the Pangean super continent We already avoid living in the interior of Australia, because living at temperatures of +50°C is just not very compatible with having body temperature slightly below +37°C. Same applies to the middle of Sahara desert. It's not impossible though, because the humidity is very low there, so, given a supply of water, you can cool by evaporation. At high humidity. you'd just die; such things happen during heat waves on the Indian subcontinent, for example.
- samatman 2y ago
  People certainly die during heat waves, on the Subcontinent and elsewhere. High heat at high humidity is dangerous to endure. However, there is no historical record of the wet bulb temperature outdoors exceeding human body temperature, anywhere, ever. So far. Which is what it would take for the human body to be unable to remove excess heat in any fashion.
  - ordinaryradical 2y ago
    See also: chapter one of Kim Stanley Robinson’s The Ministry for the Future.
  - relaxing 2y ago
    > However, there is no historical record of the wet bulb temperature outdoors That’s not really saying much. The historical record is vanishingly small.
  - gaadd33 2y ago
    The current record of 36.6 seems like it would be close enough to cause major issues.
tbrownaw 2y ago
> Individual pulses of cold climate within an ice age are termed [...] ([...] or colloquially, ice ages), Looks like both sides are right in this case.

nosianu 2y ago

I will not argue about definitions of terms, but there was a recent study that I found linked on washingtonpost.com I believe (Edit: found, added). WP article: https://www.washingtonpost.com/climate-environment/2024/09/19/earth-temperature-global-warming-planet/ https://www.washingtonpost.com/climate-environment/2024/09/1... (https://archive.md/RM8ez https://archive.md/RM8ez) > ...humans evolved during the coldest epoch of the Phanerozoic [the time period from 540 million years ago to the present], when global average temperatures were as low as 51.8 F (11 C). > “We built our civilization around those geologic landscapes of an icehouse,” Judd [one of the study's authors] said. Study (restricted): "A 485-million-year history of Earth’s surface temperature" -- https://www.science.org/doi/10.1126/science.adk3705 https://www.science.org/doi/10.1126/science.adk3705 > Partitioning the reconstruction into climate states indicates that more time was spent in warmer rather than colder climates Look at the graph - our time is on the very right. We humans developed and are still living in unusually cold times for this planet, historically.