5 ms·

Receding ice sheets don't terrify you? The felling of rainforest, the Earth's inhaler of carbon dioxide. Disappearing. All because of one species. Human bei

Receding ice sheets don't terrify you? The felling of rainforest, the Earth's inhaler of carbon dioxide. Disappearing. All because of one species. Human beings. That is a chilling.

dylangs1030 13y ago
I don't mean to diminish your point, as I fully agree with environmental concerns. But I laughed when you said it's chilling that the ice sheets are receding.
- coherentpony 13y ago
  Heh, I didn't even notice that.
nathannecro 13y ago
Sorry to burst your bubble, but you may be vastly overreacting. Talking about what's happening in both the Atlantic ice sheets and the Antarctic ice shelves can become complicated, and as far as I can tell (someone please correct me if I'm wrong) not definitive by any means. However, rainforests are by no means the "Earth's inhaler of carbon dioxide (and by extension I took that to mean 'oxygen producer' as well)". According to many sources (http://en.wikipedia.org/wiki/Rainforest#Tropical http://en.wikipedia.org/wiki/Rainforest#Tropical, http://www.columbia.edu/cu/21stC/issue-2.1/broecker.htm http://www.columbia.edu/cu/21stC/issue-2.1/broecker.htm, http://www.iub.edu/~act/files/publications/1992-93/93-03_Deforestation_LandUse.pdf http://www.iub.edu/~act/files/publications/1992-93/93-03_Def...), rainforests do not contribute much to global oxygenation. In fact, organisms like the prochlorococcus http://en.wikipedia.org/wiki/Prochlorococcus http://en.wikipedia.org/wiki/Prochlorococcus have been theorized to be responsible for at least 50% to 60% of the world's atmospheric oxygen (http://www.nature.com/nature/journal/v424/n6952/full/nature01947.html http://www.nature.com/nature/journal/v424/n6952/full/nature0... there's a paper in the references there which has that statistic, but I don't remember which). Today, these microbes are still hard at work, churning out oxygen and while some mistakes have been made (iron seeding, etc) they're still the most populous microbe on the planet. I would also contest the point about human beings. (This is my opinion talking now). I will not disagree that the earth's climate is changing rather rapidly (relative to the measurable past). I will argue though that it is arrogant to presume that humans are the root cause. On a micro scale, humans have been rather destructive to specific ecosystems. However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale.
- danmaz74 13y ago
  "However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale" Ok, let's start with something easier. Can we agree on the magnitude of the global changes that humans caused on the extension of forests and on the concentration of CO2 in the atmosphere?
- yread 13y ago
  Humas produce on the order of 3.10^13 kg of CO2 [1] Atmosphere weighs 5.1 . 10^18 [2] so the CO2 we produce is 1/100000 (or 0.001%) of the total weight. Atmosphere contains 0.046% CO2 by weight [3]. So, next year, it's going to be 0.047% [1] http://www.epa.gov/climatechange/ghgemissions/global.html http://www.epa.gov/climatechange/ghgemissions/global.html [2] http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.htm... [3] http://www.engineeringtoolbox.com/air-composition-d_212.html http://www.engineeringtoolbox.com/air-composition-d_212.html
  - simon02 13y ago
    So you are saying we increase the relative amount of CO2 with 2% (47/46) per year and try to brush that away as peanuts?
    - yread 13y ago
      I'm sorry you understood it that way. I wanted to point out that it is in fact a pretty big deal! Human produced CO2 (mainly from fossil fuel burning) is changing the global environment pretty dramatically. nathannecro wanted to see evidence that we're doing something on the macro scale, here it is.
  - jazzyjaffa 13y ago
    Your argument is completely spurious - the relative weight of our emission is not what determines if we change the climate. It would be like saying the average human weighs 70Kg so 500micrograms of LSD will do nothing as it is only 7.14^-7% of the body mass.
- 13y ago
brc 13y ago
Ice sheets don't concern me one bit. Ice and cold is definitely one thing humanity can do with less of. Felling of rainforest is more of a concern for me. Especially when it is for palm oil, soybean and sugar cane plantations to produce bio fuel. That one makes me quite concerned.
- turing 13y ago
  "Ice sheets don't concern me one bit. Ice and cold is definitely one thing humanity can do with less of." You say that as if the melting of the ice sheets doesn't have its own downstream effects on the world's climate and ecosystems.
ars 13y ago
> The felling of rainforest, the Earth's inhaler of carbon dioxide. Actually, if (and I'm aware it's a big if) they cut down the rainforest and plant new trees there, it's actually a net win for carbon dioxide. There is nothing better for carbon dioxide than cutting down a tree and using it for wood or paper AND replacing it with a new young tree. Of course I don't know if they are actually doing that. And it's likely to be bad for the animals that live there. Best would be to thin the forest, and plant new trees as you go. (Or let the forest self seed.)
- markdown 13y ago
  > Actually, if (and I'm aware it's a big if) they cut down the rainforest and plant new trees there, it's actually a net win for carbon dioxide. I believe it depends on what you do with those trees. A lot of the deforestation occurs through burning. An area is logged (bad for the ecosystem, not so bad for carbon), then its cleared by burning (bad for carbon) to make room for farmland.
  - yread 13y ago
    > to make room for farmland (bad for carbon if they feed livestock or use fertilizers there)
- kaybe 13y ago
  Depends on the soil. Rain forest soil is not very fertile, and the vegetation is quick to recycle - most nutrients are in the very top layer and in the plants at all times. Thus if you take away the trees without letting them rot and release the nutrients you could run into problems very soon. In mid-latitudes, on the other hand, it's not as big a problem because the recycling is a lot slower and the reservoir is far greater.
rimantas 13y ago
90% of species that ever lived on Earth are gone without any help from humans.
- polymatter 13y ago
  and we're rapidly getting through the remaining 10% too.
  - rfatnabayeff 13y ago
    so if it's fine with the vanished 90%, why should one be bothered about 10%?
    - itsybitsycoder 13y ago
      Because we are in that remaining 10%, as are all of the species we rely on for food. Most people have an interest in the continuation of humanity, at least in theory.
      - rfatnabayeff 13y ago
        Most people is interested in continuation of themselves and their close relatives. Seven billion of people, driven by this interest, form a hivemind that dictates their own fate. Should it be the extinction of 9.999% of species - so be it.
icefox 13y ago
The rainforest's use up almost all of the oxygen that they put out. As far as carbon dioxide they are pretty net zero in the end. It is the Algie blooms that produce the oxygen surplus. While fun to say, rainforest's are not the earth's lungs. But don't take my word for it, checkout either the very good video (or search the transcript for "lungs") http://www.pbs.org/wgbh/nova/space/earth-from-space.html http://www.pbs.org/wgbh/nova/space/earth-from-space.html

Receding ice sheets don't terrify you? The felling of rainforest, the Earth's inhaler of carbon dioxide. Disappearing. All because of one species. Human beings. That is a chilling.

dylangs1030 13y ago

I don't mean to diminish your point, as I fully agree with environmental concerns. But I laughed when you said it's chilling that the ice sheets are receding.

coherentpony 13y ago
Heh, I didn't even notice that.

nathannecro 13y ago

Sorry to burst your bubble, but you may be vastly overreacting. Talking about what's happening in both the Atlantic ice sheets and the Antarctic ice shelves can become complicated, and as far as I can tell (someone please correct me if I'm wrong) not definitive by any means. However, rainforests are by no means the "Earth's inhaler of carbon dioxide (and by extension I took that to mean 'oxygen producer' as well)". According to many sources (http://en.wikipedia.org/wiki/Rainforest#Tropical http://en.wikipedia.org/wiki/Rainforest#Tropical, http://www.columbia.edu/cu/21stC/issue-2.1/broecker.htm http://www.columbia.edu/cu/21stC/issue-2.1/broecker.htm, http://www.iub.edu/~act/files/publications/1992-93/93-03_Deforestation_LandUse.pdf http://www.iub.edu/~act/files/publications/1992-93/93-03_Def...), rainforests do not contribute much to global oxygenation. In fact, organisms like the prochlorococcus http://en.wikipedia.org/wiki/Prochlorococcus http://en.wikipedia.org/wiki/Prochlorococcus have been theorized to be responsible for at least 50% to 60% of the world's atmospheric oxygen (http://www.nature.com/nature/journal/v424/n6952/full/nature01947.html http://www.nature.com/nature/journal/v424/n6952/full/nature0... there's a paper in the references there which has that statistic, but I don't remember which). Today, these microbes are still hard at work, churning out oxygen and while some mistakes have been made (iron seeding, etc) they're still the most populous microbe on the planet. I would also contest the point about human beings. (This is my opinion talking now). I will not disagree that the earth's climate is changing rather rapidly (relative to the measurable past). I will argue though that it is arrogant to presume that humans are the root cause. On a micro scale, humans have been rather destructive to specific ecosystems. However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale.

danmaz74 13y ago
"However, I have yet to see convincing proof that humans can effect climate change to this magnitude on a macro scale" Ok, let's start with something easier. Can we agree on the magnitude of the global changes that humans caused on the extension of forests and on the concentration of CO2 in the atmosphere?
yread 13y ago
Humas produce on the order of 3.10^13 kg of CO2 [1] Atmosphere weighs 5.1 . 10^18 [2] so the CO2 we produce is 1/100000 (or 0.001%) of the total weight. Atmosphere contains 0.046% CO2 by weight [3]. So, next year, it's going to be 0.047% [1] http://www.epa.gov/climatechange/ghgemissions/global.html http://www.epa.gov/climatechange/ghgemissions/global.html [2] http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.html http://nssdc.gsfc.nasa.gov/planetary/factsheet/earthfact.htm... [3] http://www.engineeringtoolbox.com/air-composition-d_212.html http://www.engineeringtoolbox.com/air-composition-d_212.html
- simon02 13y ago
  So you are saying we increase the relative amount of CO2 with 2% (47/46) per year and try to brush that away as peanuts?
  - yread 13y ago
    I'm sorry you understood it that way. I wanted to point out that it is in fact a pretty big deal! Human produced CO2 (mainly from fossil fuel burning) is changing the global environment pretty dramatically. nathannecro wanted to see evidence that we're doing something on the macro scale, here it is.
- jazzyjaffa 13y ago
  Your argument is completely spurious - the relative weight of our emission is not what determines if we change the climate. It would be like saying the average human weighs 70Kg so 500micrograms of LSD will do nothing as it is only 7.14^-7% of the body mass.
13y ago

brc 13y ago

Ice sheets don't concern me one bit. Ice and cold is definitely one thing humanity can do with less of. Felling of rainforest is more of a concern for me. Especially when it is for palm oil, soybean and sugar cane plantations to produce bio fuel. That one makes me quite concerned.

turing 13y ago
"Ice sheets don't concern me one bit. Ice and cold is definitely one thing humanity can do with less of." You say that as if the melting of the ice sheets doesn't have its own downstream effects on the world's climate and ecosystems.

ars 13y ago

> The felling of rainforest, the Earth's inhaler of carbon dioxide. Actually, if (and I'm aware it's a big if) they cut down the rainforest and plant new trees there, it's actually a net win for carbon dioxide. There is nothing better for carbon dioxide than cutting down a tree and using it for wood or paper AND replacing it with a new young tree. Of course I don't know if they are actually doing that. And it's likely to be bad for the animals that live there. Best would be to thin the forest, and plant new trees as you go. (Or let the forest self seed.)

markdown 13y ago
> Actually, if (and I'm aware it's a big if) they cut down the rainforest and plant new trees there, it's actually a net win for carbon dioxide. I believe it depends on what you do with those trees. A lot of the deforestation occurs through burning. An area is logged (bad for the ecosystem, not so bad for carbon), then its cleared by burning (bad for carbon) to make room for farmland.
- yread 13y ago
  > to make room for farmland (bad for carbon if they feed livestock or use fertilizers there)
kaybe 13y ago
Depends on the soil. Rain forest soil is not very fertile, and the vegetation is quick to recycle - most nutrients are in the very top layer and in the plants at all times. Thus if you take away the trees without letting them rot and release the nutrients you could run into problems very soon. In mid-latitudes, on the other hand, it's not as big a problem because the recycling is a lot slower and the reservoir is far greater.

rimantas 13y ago

90% of species that ever lived on Earth are gone without any help from humans.

polymatter 13y ago
and we're rapidly getting through the remaining 10% too.
- rfatnabayeff 13y ago
  so if it's fine with the vanished 90%, why should one be bothered about 10%?
  - itsybitsycoder 13y ago
    Because we are in that remaining 10%, as are all of the species we rely on for food. Most people have an interest in the continuation of humanity, at least in theory.
    - rfatnabayeff 13y ago
      Most people is interested in continuation of themselves and their close relatives. Seven billion of people, driven by this interest, form a hivemind that dictates their own fate. Should it be the extinction of 9.999% of species - so be it.

icefox 13y ago

The rainforest's use up almost all of the oxygen that they put out. As far as carbon dioxide they are pretty net zero in the end. It is the Algie blooms that produce the oxygen surplus. While fun to say, rainforest's are not the earth's lungs. But don't take my word for it, checkout either the very good video (or search the transcript for "lungs") http://www.pbs.org/wgbh/nova/space/earth-from-space.html http://www.pbs.org/wgbh/nova/space/earth-from-space.html