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As opposed to our current icehouse phase, plants have thrived during intense greenhouse periods of global climate. "Earth has been in a greenhouse state for ab

by chasil 3y ago

As opposed to our current icehouse phase, plants have thrived during intense greenhouse periods of global climate. "Earth has been in a greenhouse state for about 85% of its history... Earth is now in an icehouse state, and ice sheets are present in both poles simultaneously." https://en.m.wikipedia.org/wiki/Greenhouse_and_icehouse_Earth https://en.m.wikipedia.org/wiki/Greenhouse_and_icehouse_Eart...

ido 3y ago
Did the livestock and cultivated plants we depend on for food exist during the greenhouse states? Did humans? There’s no doubt the earth and life will survive, but our civilization may see extreme turbulence (100s of millions of people dying). How much turbulence before our sophisticated society collapses? We don't know for sure but I rather not find out.
- no_wizard 3y ago
  >100s of millions of people dying This seems optimistic to me. With the state of play of current politics across the globe, I think its going to be a ~billion once you tabulate second order effects. Already under current changing patterns of climate, there are areas of the world that if power simply went out for an extended period of time millions of people could die, and those areas are growing every year
janice1999 3y ago
Crops need water, stable climates and human intervention. Global heating is driving desertification, droughts and more extreme weather events.
Qwertious 3y ago
The earth is 4.5 billion years old. Over those billions of years, the sun has gotten ~40% hotter, which counteracted the reduced atmospheric greenhouse effect. We can't directly compare our current climate to billions of years ago with just atmospheric conditions. Also, I notice you said "plants have thrived", and not "major staple crops have thrived". Toxic algae bloom has its own sort of natural beauty I guess, but rice and wheat are both temperate crops and won't be able to grow near the equator if it gets much hotter. Please note that while hotter temps would warm up croplands near the poles, heat is not light and the tropics are so valuable for farming because they receive more light, not because they're hotter.
- btbuildem 3y ago
  Also, there's far less area of land near the poles, despite of what Mercator would have us believe.
  - Jensson 3y ago
    That is a lie, there is much more land to the north than at the equator. Not as much as Mercator might make you believe, but it is still way more since it is mostly water around the equator. https://www.ecoclimax.com/2016/08/land-mass-at-each-longitude-and-latitude.html https://www.ecoclimax.com/2016/08/land-mass-at-each-longitud...
jijijijij 3y ago
We're not talking about the overall greenhouse situation, but particular regions experiencing high wet-bulb temperatures, or intense heat waves, and acute plant resilience in relation to human survivability. I am very aware some plants can manage and adapt. But for example there is a difference between C3 and C4 plants in regard to heat tolerance and distribution. The question is, can all plants manage in a given region, in a given moment of time, with a shift in competitive advantage for certain organisms around? Geological or evolutionary time scales are irrelevant, here, since we're talking about the years to come - a human life time. A temporary disturbance of a single factor may kill an ecosystem. For example eutrophication in lakes may lead to algae bloom, killing all other plants, fish and animals around. Or the extermination of the wolf, or another top predator, leads to overgrowth of deer, or another important prey animal, which then will eat all the young trees, which leads to receding forests, leading to increased soil erosion by wind, and leading to decreased rainfall, which ultimately leads to desertification or aridification. An instant 10% increased fitness for some opportunistic fungi could wreak havoc in a particular ecosystem. 10% decreased fitness for a local tree species, too. A general loss of diversity may lead to bad adaptability for periodic stress events. But you won't find evidence of these isolated catastrophes in fossils or drill cores. You don't see the farewell messages from all those species who didn't make it.
itishappy 3y ago
Great, but I don't really care about plants. Did humans thrive too?
no_wizard 3y ago
It would also appear that icehouse periods last significantly shorter than greenhouse periods. No doubt, if I assume everything reported on Wikipedia is accurate, humanity has never had to sustain itself in the face of a greenhouse period, given we only existed approximately 2.8 million years ago, and in "modern" form for only ~300,000 years. That should give more pause than it does to society writ large, but alas, because humans are generally poor at long term planning and thinking, it appears we are dooming ourselves to be ill prepared.

by chasil 3y ago

ido 3y ago

Did the livestock and cultivated plants we depend on for food exist during the greenhouse states? Did humans? There’s no doubt the earth and life will survive, but our civilization may see extreme turbulence (100s of millions of people dying). How much turbulence before our sophisticated society collapses? We don't know for sure but I rather not find out.

no_wizard 3y ago
>100s of millions of people dying This seems optimistic to me. With the state of play of current politics across the globe, I think its going to be a ~billion once you tabulate second order effects. Already under current changing patterns of climate, there are areas of the world that if power simply went out for an extended period of time millions of people could die, and those areas are growing every year

janice1999 3y ago

Crops need water, stable climates and human intervention. Global heating is driving desertification, droughts and more extreme weather events.

Qwertious 3y ago

The earth is 4.5 billion years old. Over those billions of years, the sun has gotten ~40% hotter, which counteracted the reduced atmospheric greenhouse effect. We can't directly compare our current climate to billions of years ago with just atmospheric conditions. Also, I notice you said "plants have thrived", and not "major staple crops have thrived". Toxic algae bloom has its own sort of natural beauty I guess, but rice and wheat are both temperate crops and won't be able to grow near the equator if it gets much hotter. Please note that while hotter temps would warm up croplands near the poles, heat is not light and the tropics are so valuable for farming because they receive more light, not because they're hotter.

btbuildem 3y ago
Also, there's far less area of land near the poles, despite of what Mercator would have us believe.
- Jensson 3y ago
  That is a lie, there is much more land to the north than at the equator. Not as much as Mercator might make you believe, but it is still way more since it is mostly water around the equator. https://www.ecoclimax.com/2016/08/land-mass-at-each-longitude-and-latitude.html https://www.ecoclimax.com/2016/08/land-mass-at-each-longitud...

jijijijij 3y ago

We're not talking about the overall greenhouse situation, but particular regions experiencing high wet-bulb temperatures, or intense heat waves, and acute plant resilience in relation to human survivability. I am very aware some plants can manage and adapt. But for example there is a difference between C3 and C4 plants in regard to heat tolerance and distribution. The question is, can all plants manage in a given region, in a given moment of time, with a shift in competitive advantage for certain organisms around? Geological or evolutionary time scales are irrelevant, here, since we're talking about the years to come - a human life time. A temporary disturbance of a single factor may kill an ecosystem. For example eutrophication in lakes may lead to algae bloom, killing all other plants, fish and animals around. Or the extermination of the wolf, or another top predator, leads to overgrowth of deer, or another important prey animal, which then will eat all the young trees, which leads to receding forests, leading to increased soil erosion by wind, and leading to decreased rainfall, which ultimately leads to desertification or aridification. An instant 10% increased fitness for some opportunistic fungi could wreak havoc in a particular ecosystem. 10% decreased fitness for a local tree species, too. A general loss of diversity may lead to bad adaptability for periodic stress events. But you won't find evidence of these isolated catastrophes in fossils or drill cores. You don't see the farewell messages from all those species who didn't make it.

itishappy 3y ago

Great, but I don't really care about plants. Did humans thrive too?

no_wizard 3y ago

It would also appear that icehouse periods last significantly shorter than greenhouse periods. No doubt, if I assume everything reported on Wikipedia is accurate, humanity has never had to sustain itself in the face of a greenhouse period, given we only existed approximately 2.8 million years ago, and in "modern" form for only ~300,000 years. That should give more pause than it does to society writ large, but alas, because humans are generally poor at long term planning and thinking, it appears we are dooming ourselves to be ill prepared.