4 ms·

Just as a reminder, 2100 is closer to us than 1940. The future is rushing at us fast. As for the Amazon becoming a barren wasteland, an epiphany moment for me

by titzer 5y ago

Just as a reminder, 2100 is closer to us than 1940. The future is rushing at us fast. As for the Amazon becoming a barren wasteland, an epiphany moment for me was to realize that the rainforest isn't a rainforest because it just happens to be where it rains a lot, it rains a lot because of the dense biomass of trees that repeatedly pump the rainwater out of the ground, fueling a huge biosphere from which it escapes as vapor, where it condenses again as rain, not far away. The Amazon continually recycles its water. Without that rainforest that rain will just end going underground, into the watertable or into the Amazon river, likely taking the topsoil with it. The evidence that this can happen isn't all that far away. Many regions of Africa have geologic evidence of shifting multiple times from being desert, to being forest, grassland, savannah, rainforest, and back. The cycles might be over hundreds of thousands or millions of years. Mankind's release of massive CO2, plus our deforestation habit, might indeed cause a catastrophic cascade of this region in mere centuries.

cjensen 5y ago
That's an incorrect understanding of rainforests, and has me scratching my head at the article. It rains because of Hadley cells. Hadley cells don't disappear with global warming, so it will still rain a lot in the tropics. Why on Earth would it be "barren?" A few degrees of temperature doesn't matter to plants: as long as there is sunlight and tons of water, they should be fine. Now if Hadley cells widen or shift northward, that could be a problem for the US. But no matter what happens, Hadley cells still have to rise near the equator.
- lkrubner 5y ago
  No, you're putting too much emphasis on Hadley cells. The air patterns are only one part of a very much more complex cycle. As the poster above you noted, for any given amount of water, the amount going into the air in a particular place is influenced by the density of plants. Plants pull water from underground and help evaporate it in one particular place. The evaporated air can then condense and become rain again. Therefore, very dense masses of plants can increase the rate with which water is pulled from the ground and then evaporate and then condenses into rain and then returns to the ground, starting the cycle over again. Remove the trees and you still have Hadley cells, but you won't have a rainforest anymore, if the density of the plants falls below some threshold -- you won't have as much rain, even though the Hadley cell is still there -- you might have the same amount of water, but the speed at which it evaporates, and therefore becomes rain, will be lessened.
- titzer 5y ago
  > as long as there is sunlight and tons of water, they should be fine. That's completely ridiculous. Plants don't fit your magical conception of them. Talk to any farmer or someone with a degree in forestry. Every species has its preferred temperate zones, moisture, and sunlight requirements. Heck, a gardner will tell you that. Plants need to be pollinated. The pollinators die, the plants die. Plants don't break down dead plants. Fungus, insects, and herbivores do. Those parts of the ecosystem die, plants die too. Throw in invasive species, pests like bark beetles that won't die in winter, and you can absolutely expect forests to collapse. Everything is connected. It's a system with millions of parts. It's already showing signs of abuse. Collapse is starting. Forests are weakening, tree lines are changing, some whole regions are showing signs they may die off. I've seen it with my own eyes in SW Utah. Biologists see climate change happening everywhere. We're looking at vast loss of biodiversity and collapse of ecosystems as things speed up.
  - goatlover 5y ago
    It's ridiculous to think that whole ecosystems will just collapse instead of adapt with the species that are good generalists and can manage a warmer climate and the ongoing impact of humans. Plenty of wildlife manages to live inside cities, including various plants, fungi, insects, birds and mammals. Will it be pristine and as diverse before? No, but it will be what survives, as has always been the case on Earth since life evolved. Some parts of forests and ecosystems will die and other parts will take their place, and some will do even better because it's warmer with more CO2. Not always what we'd like, but nature will be there in one form or another. The current diversity of the world evolved form times of less diversity which came from times of greater diversity and so on for several major and minor extinctions over the past couple billion years, and plenty of upheaval on more local and regional scales. Nature is always changing and adapting. There are always species migrating around and adapting or going extinct.
    - jschwartzi 5y ago
      All of the trees I’ve seen where I live have been damaged either by the current drought or by various bark beetle attacks. All of them. We had to cut down a birch tree that was girdled by bark beetles, and I’m very worried about the mature red cedars on our property surviving the next ten years. You can drive around the city here and count dead or dying trees. Tell me how are they supposed to adapt?
titzer 5y ago
> in mere centuries. I'll just add to my own comment that 3% economic growth for 480 years would mean the economy in 2500 would be 1,500,000 times its current size today and in the year 3000 almost 3.8 trillion times its current size. So obviously, exponential growth is going to come to an end, probably slowing down this century and we will absolutely have to reach sustainability on Earth.
- 0xB31B1B 5y ago
  "exponential growth is going to come to an end" We're literally just hitting the part of economic development where the highest impacts to output are not resource intensive but rather intellectual property intensive, and also difficult to measure by a traditional measure like GDP. How do you measure the economic impact of say, wikipedia, in terms of GDP? Its free, it raises funds only through donations, and it has immense value. We're just getting started with exponential growth, and we're just getting started because we're finally decoupling growth from physical resources
  - croes 5y ago
    Even things like Wikipedia need physical resources like servers and have a large energie consumption.
    - romski 5y ago
      Trivial compared to their value.
  - gerbilly 5y ago
    >We're literally just hitting the part of economic development where the highest impacts to output are not resource intensive but rather intellectual property intensive I hope they issue patents on good edible paper then, because if the climate changes as much as this study proposes, all this intellectual property won’t matter much.
  - runako 5y ago
    > are not resource intensive but rather intellectual property intensive, Just in time for folks to invent mechanisms to convert IP intensity to physical resource intensity via e.g. blockchains.
gonzo41 5y ago
Time to plant a forest the size of England in the centre of Australia then. We can pump and desalinated the water for 100 years on solar and eventually it'll just do it itself
- soperj 5y ago
  If you plant eucalyptus then you don't even need to desalinate.
  - gonzo41 5y ago
    The fires become a worry with those.
    - soperj 5y ago
      Fires are part of the life of a forest.
0x0nyandesu 5y ago
That's only half of it. It rains in the Amazon so much also because of the Andes pushing air from the oceans up where it condenses. You can see this happening in Hawaii in real time everyday where one side is a lush jungle and the other side is Mediterranean style desert similar to southern California and there's no way it's purely from the jungle. It's mostly coming off the ocean
- gerbilly 5y ago
  Trees make their own rain, it’s a known thing, and if the moisture was only from the ocean then you’d expect it to rain to the west of the mountains not to the east.
  - 0x0nyandesu 5y ago
    Yes. I've literally seen it in action on Maui and in Japan at Yakushima. But this system requires constant input from the ocean trade winds.
throwawaycities 5y ago
> it rains a lot because of the dense biomass of trees that repeatedly pump the rainwater out of the ground Even on very small scales like local botanical gardens with rainforest sections they are typically cooler and more humid than other sections of the gardens. The rainforest section of Fairchild Tropical Gardens in Miami often develops its own fog/mist not present in the other sections which is pretty nice on a hot Miami day.
heavyset_go 5y ago
> Many regions of Africa have geologic evidence of shifting multiple times from being desert, to being forest, grassland, savannah, rainforest, and back. About six thousand years ago, the Sahara itself was largely rainy grasslands.
coolgeek 5y ago
> Just as a reminder, 2100 is closer to us than 1940. The future is rushing at us fast. Most people reading this here and now (today, the day it was posted) aren't going to see 2100. I'm not making this comment in order to dissuade anyone from doing everything they can to halt or reverse climate change. I'm simply being realistic. 2100 is 79 years from now. Barring significant medical advances - the likes of which have never been seen before - almost none of the adults here will be alive in 2100.

by titzer 5y ago

cjensen 5y ago

That's an incorrect understanding of rainforests, and has me scratching my head at the article. It rains because of Hadley cells. Hadley cells don't disappear with global warming, so it will still rain a lot in the tropics. Why on Earth would it be "barren?" A few degrees of temperature doesn't matter to plants: as long as there is sunlight and tons of water, they should be fine. Now if Hadley cells widen or shift northward, that could be a problem for the US. But no matter what happens, Hadley cells still have to rise near the equator.

lkrubner 5y ago
No, you're putting too much emphasis on Hadley cells. The air patterns are only one part of a very much more complex cycle. As the poster above you noted, for any given amount of water, the amount going into the air in a particular place is influenced by the density of plants. Plants pull water from underground and help evaporate it in one particular place. The evaporated air can then condense and become rain again. Therefore, very dense masses of plants can increase the rate with which water is pulled from the ground and then evaporate and then condenses into rain and then returns to the ground, starting the cycle over again. Remove the trees and you still have Hadley cells, but you won't have a rainforest anymore, if the density of the plants falls below some threshold -- you won't have as much rain, even though the Hadley cell is still there -- you might have the same amount of water, but the speed at which it evaporates, and therefore becomes rain, will be lessened.
titzer 5y ago
> as long as there is sunlight and tons of water, they should be fine. That's completely ridiculous. Plants don't fit your magical conception of them. Talk to any farmer or someone with a degree in forestry. Every species has its preferred temperate zones, moisture, and sunlight requirements. Heck, a gardner will tell you that. Plants need to be pollinated. The pollinators die, the plants die. Plants don't break down dead plants. Fungus, insects, and herbivores do. Those parts of the ecosystem die, plants die too. Throw in invasive species, pests like bark beetles that won't die in winter, and you can absolutely expect forests to collapse. Everything is connected. It's a system with millions of parts. It's already showing signs of abuse. Collapse is starting. Forests are weakening, tree lines are changing, some whole regions are showing signs they may die off. I've seen it with my own eyes in SW Utah. Biologists see climate change happening everywhere. We're looking at vast loss of biodiversity and collapse of ecosystems as things speed up.
- goatlover 5y ago
  It's ridiculous to think that whole ecosystems will just collapse instead of adapt with the species that are good generalists and can manage a warmer climate and the ongoing impact of humans. Plenty of wildlife manages to live inside cities, including various plants, fungi, insects, birds and mammals. Will it be pristine and as diverse before? No, but it will be what survives, as has always been the case on Earth since life evolved. Some parts of forests and ecosystems will die and other parts will take their place, and some will do even better because it's warmer with more CO2. Not always what we'd like, but nature will be there in one form or another. The current diversity of the world evolved form times of less diversity which came from times of greater diversity and so on for several major and minor extinctions over the past couple billion years, and plenty of upheaval on more local and regional scales. Nature is always changing and adapting. There are always species migrating around and adapting or going extinct.
  - jschwartzi 5y ago
    All of the trees I’ve seen where I live have been damaged either by the current drought or by various bark beetle attacks. All of them. We had to cut down a birch tree that was girdled by bark beetles, and I’m very worried about the mature red cedars on our property surviving the next ten years. You can drive around the city here and count dead or dying trees. Tell me how are they supposed to adapt?

titzer 5y ago

> in mere centuries. I'll just add to my own comment that 3% economic growth for 480 years would mean the economy in 2500 would be 1,500,000 times its current size today and in the year 3000 almost 3.8 trillion times its current size. So obviously, exponential growth is going to come to an end, probably slowing down this century and we will absolutely have to reach sustainability on Earth.

0xB31B1B 5y ago
"exponential growth is going to come to an end" We're literally just hitting the part of economic development where the highest impacts to output are not resource intensive but rather intellectual property intensive, and also difficult to measure by a traditional measure like GDP. How do you measure the economic impact of say, wikipedia, in terms of GDP? Its free, it raises funds only through donations, and it has immense value. We're just getting started with exponential growth, and we're just getting started because we're finally decoupling growth from physical resources
- croes 5y ago
  Even things like Wikipedia need physical resources like servers and have a large energie consumption.
  - romski 5y ago
    Trivial compared to their value.
- gerbilly 5y ago
  >We're literally just hitting the part of economic development where the highest impacts to output are not resource intensive but rather intellectual property intensive I hope they issue patents on good edible paper then, because if the climate changes as much as this study proposes, all this intellectual property won’t matter much.
- runako 5y ago
  > are not resource intensive but rather intellectual property intensive, Just in time for folks to invent mechanisms to convert IP intensity to physical resource intensity via e.g. blockchains.

gonzo41 5y ago

Time to plant a forest the size of England in the centre of Australia then. We can pump and desalinated the water for 100 years on solar and eventually it'll just do it itself

soperj 5y ago
If you plant eucalyptus then you don't even need to desalinate.
- gonzo41 5y ago
  The fires become a worry with those.
  - soperj 5y ago
    Fires are part of the life of a forest.

0x0nyandesu 5y ago

That's only half of it. It rains in the Amazon so much also because of the Andes pushing air from the oceans up where it condenses. You can see this happening in Hawaii in real time everyday where one side is a lush jungle and the other side is Mediterranean style desert similar to southern California and there's no way it's purely from the jungle. It's mostly coming off the ocean

gerbilly 5y ago
Trees make their own rain, it’s a known thing, and if the moisture was only from the ocean then you’d expect it to rain to the west of the mountains not to the east.
- 0x0nyandesu 5y ago
  Yes. I've literally seen it in action on Maui and in Japan at Yakushima. But this system requires constant input from the ocean trade winds.

throwawaycities 5y ago

> it rains a lot because of the dense biomass of trees that repeatedly pump the rainwater out of the ground Even on very small scales like local botanical gardens with rainforest sections they are typically cooler and more humid than other sections of the gardens. The rainforest section of Fairchild Tropical Gardens in Miami often develops its own fog/mist not present in the other sections which is pretty nice on a hot Miami day.

heavyset_go 5y ago

> Many regions of Africa have geologic evidence of shifting multiple times from being desert, to being forest, grassland, savannah, rainforest, and back. About six thousand years ago, the Sahara itself was largely rainy grasslands.

coolgeek 5y ago

> Just as a reminder, 2100 is closer to us than 1940. The future is rushing at us fast. Most people reading this here and now (today, the day it was posted) aren't going to see 2100. I'm not making this comment in order to dissuade anyone from doing everything they can to halt or reverse climate change. I'm simply being realistic. 2100 is 79 years from now. Barring significant medical advances - the likes of which have never been seen before - almost none of the adults here will be alive in 2100.