[Dr. Ofellati]

Guy publishes well supported article that says Easter Islanders likely wiped themselves out by chopping down all their trees. Very clearly possible, very clearly likely. No need to invoke climate change - just simply a very small island with a small forest that was rapidly cut to stumps.

BTW, you do realize that local climate is impacted by forest cover, don't you? Forest systems are water storage systems and it can impact temperature and rainfall patterns the way, let's say, an adjacent lake might.

So there is an intersection point between deforestation and climate.

I agree, of course.

The issue is not one of possibility, but rather of probability.

I'd say the probabilities lie with extended drought, disease, war, and the like.
I'd say it's possible, but much less likely, that stone-axe wielding ancients were able to change the climate - local or otherwise - sufficiently to make farming impossible.
I'd say the author went looking for an historic example of human-induced climate change and was dedicated to finding one whether one existed.

[rangerone314]

While I have no doubt that we will continue to poison our Petri dish, I always question whether conclusions such as the ones drawn in the referenced work are politically motivated or scientifically motivated.

To wit, it seems unlikely that, working with nothing but stone axes and/or fire, and then farming the land by hand or with light animals, an indigenous S. American population could have put even a minor dent in the forest.

If you don't believe me, go clear 20 acres by hand and then try to keep it clear. By hand. Good luck with that.

A. You are assuming a tree density like the Amazon or East Coast temperate. Ever see what passes for a "forest" in southern California? I do, I lived there 3 years.
B. The Nazca had multiple hundreds of years to put more than a "minor dent in the forest".
C. Time or skill did not seem to be a problem for the Nazca. Ever see the Nazca lines that are only visible by aircraft?
D. Weeds can grow quickly. Trees generally take more time to grow back.
E. A lot of things seem "unlikely" with ancient peoples (consider Stonehenge or Malta temple complexes) but they did them anyway. Ancient people were resourceful ...
F. It is real hard to keep an area clear. Its just a good thing the Easter Island people to the west of the Nazca had chainsaws and tractors when they took down the trees.

I think more people need to read Diamond's book: "Collapse. How Societies Choose to Fail or Succeed"

[Dr. Ofellati]

A. You are assuming a tree density like the Amazon or East Coast temperate. Ever see what passes for a "forest" in southern California? I do, I lived there 3 years.

Very simply, the fewer trees there are, the less the effect on climate there will be when they are cut down. So either way, it's a stretch.

B. The Nazca had multiple hundreds of years to put more than a "minor dent in the forest".

It's not about time. Give one man a thousand years and and stone axe and he couldn't keep more than a few acres of my forested property cleared. It's about population.

C. Time or skill did not seem to be a problem for the Nazca. Ever see the Nazca lines that are only visible by aircraft?

Not sure of relevance.

D. Weeds can grow quickly. Trees generally take more time to grow back.

Same "can't have it both ways." Around here, a fallow field will have 10 foot saplings within about 5 years. If the land is so poor that trees grow back so slowly, then the tree density would have been low, which brings into question how their destruction could change the climate.

E. A lot of things seem "unlikely" with ancient peoples (consider Stonehenge or Malta temple complexes) but they did them anyway. Ancient people were resourceful ...

Stonehenge seems simple. Move a bunch of stones. Levers, ropes, lots of people.
Changing the climate by cutting down trees with stone axes seems . . . fanciful.

F. It is real hard to keep an area clear. Its just a good thing the Easter Island people to the west of the Nazca had chainsaws and tractors when they took down the trees.

1. Easter Island was tiny, population grew exponentially because food was plentiful, and they didn't change the climate.
2. Not the case with case in point.

[frankthetank]

Still think its water... without it there is nothing... with it you can have a Phoenix, AZ or a Las Vegas, NV or an overpopulated desert nation of Saudi Arabia...

Monsoon in India fails? LOTS of people die.
http://en.wikipedia.org/wiki/Famine_in_India

Cutting down the forest doesn't help...especially HUGE areas of it, like in Brazil. That could cause some serious problems.

Today we have the ability to move water around (thanks to oil/electricity)...someday it won't be so easy

[rangerone314]

A. You are assuming a tree density like the Amazon or East Coast temperate. Ever see what passes for a "forest" in southern California? I do, I lived there 3 years.

Very simply, the fewer trees there are, the less the effect on climate there will be when they are cut down. So either way, it's a stretch.

B. The Nazca had multiple hundreds of years to put more than a "minor dent in the forest".

It's not about time. Give one man a thousand years and and stone axe and he couldn't keep more than a few acres of my forested property cleared. It's about population.

C. Time or skill did not seem to be a problem for the Nazca. Ever see the Nazca lines that are only visible by aircraft?

Not sure of relevance.

D. Weeds can grow quickly. Trees generally take more time to grow back.

Same "can't have it both ways." Around here, a fallow field will have 10 foot saplings within about 5 years. If the land is so poor that trees grow back so slowly, then the tree density would have been low, which brings into question how their destruction could change the climate.

E. A lot of things seem "unlikely" with ancient peoples (consider Stonehenge or Malta temple complexes) but they did them anyway. Ancient people were resourceful ...

Stonehenge seems simple. Move a bunch of stones. Levers, ropes, lots of people.
Changing the climate by cutting down trees with stone axes seems . . . fanciful.

F. It is real hard to keep an area clear. Its just a good thing the Easter Island people to the west of the Nazca had chainsaws and tractors when they took down the trees.

1. Easter Island was tiny, population grew exponentially because food was plentiful, and they didn't change the climate.
2. Not the case with case in point.

Give an arsonist a match and he can take out 1,000 acres of trees. I would assume fire works on 10-foot saplings, as well.

I'm glad you think Stonehenge is simple. And I rather doubt there were many more people living in the Stonehenge area than Nazca area.

For a lesson in deforestation, read up on North Africa and the Sahel, and desertification.

I also emailed Bill Laurance, an Australian expert in deforestation for his opinion on permanently taking out a forest with Stone Age technology... assuming I get a reply, I'll post his response.

[Dr. Ofellati]

Give an arsonist a match and he can take out 1,000 acres of trees. I would assume fire works on 10-foot saplings, as well.

The original article says "cut," not burned, so your point, while brought up above and interesting in the abstract, is irrelevant to the thread.

I'm glad you think Stonehenge is simple. And I rather doubt there were many more people living in the Stonehenge area than Nazca area.

Do you think a few stones piled up is complex?

For a lesson in deforestation, read up on North Africa and the Sahel, and desertification.

No interest, and it wouldn't inform on the current thread.

I also emailed Bill Laurance, an Australian expert in deforestation for his opinion on permanently taking out a forest with Stone Age technology... assuming I get a reply, I'll post his response.

Great, but it will only be an interesting answer if he isn't a card carrying member of the cult of Global Warming who run around screaming "denier" at anybody, including the 1 in 8 climatologists, who don't believe that human activity is causing global warming.
Otherwise, it's just another guy with a political agenda projecting his current angst back a few centuries.

[rangerone314]

Trees can be CUT down, fallow areas could be burnt to prevent regrowth. (I would assume they would not want to waste all the wood)

The article COULD have made mention of the estimated population density.

Deforestation DOES contribute to alteration of a climate. Thus North Africa does inform. The climate does not exist in a vacuum, life and the biosphere (thin as it is) DOES change the environment. Otherwise, we would not have 16% oxygen atmosphere.

North Africa WAS the breadbasket of the Roman Empire. Now its a basket-case.

[dorlomin]

Do you think a few stones piled up is complex?

Yes.

[Roy]

Dr. O, you should read Collapse, by Jared Diamond.

He examines many different societies that collapsed due to environmental damage caused by their activities. He also looks at other factors like reliance on imports, and the robustness of the ecosystems where these societies were located and how those interacted to cause their collapse.

There are many historical examples. I think you may be underestimating the ingenuity and resourcefulness of your fellow man, stone age tools or no, to modify his environment.

[Dr. Ofellati]

Dr. O, you should read Collapse, by Jared Diamond.

He examines many different societies that collapsed due to environmental damage caused by their activities. He also looks at other factors like reliance on imports, and the robustness of the ecosystems where these societies were located and how those interacted to cause their collapse.

There are many historical examples. I think you may be underestimating the ingenuity and resourcefulness of your fellow man, stone age tools or no, to modify his environment.

You've got me interested. Before I take the plunge, what is the most famous society, other than Easter Island, that underwent an ecosystem-induced collapse?

[Vogelzang]

I'm glad my competitors are having so many psychotic attacks. While their sick, I'll steal market share from them.

[coyote]

You've got me interested. Before I take the plunge, what is the most famous society, other than Easter Island, that underwent an ecosystem-induced collapse?

The main societies Diamond discusses in the book are: modern Montana, Easter Island, Pitcairn and Henderson islands, the Anasazi, the Maya, the Greenland Norse, Rwanda, Haiti, China and Australia. But the discussion is by no means confined to eco-collapse, but a more general discussion of the various "disastrous decisions" that a society can make.

[XOVERX]

Instead of the printed book by Diamond, you may want to consider the audio book version. Slip it in your car cd player and listen while you drive. Book's done in a few short days without having to sit down, read, and concentrate. Just a thought.

[rangerone314]

Instead of the printed book by Diamond, you may want to consider the audio book version. Slip it in your car cd player and listen while you drive. Book's done in a few short days without having to sit down, read, and concentrate. Just a thought.

Days? WTF? How many pages is it?

Harry Potter book #1 only took an hour to read and it took that long cause I was drinking hot chocolate and didn't want to spill any on the book.

[Ludi]

No interest, and it wouldn't inform on the current thread.

Why waste time debating with someone who isn't interested in learning about the subject of the debate?

[XOVERX]

You can read Harry Potter in an hour? Excellent.

The Diamond book is certainly no longer than Harry Potter. I say, "a few days" only because it takes me 15 minutes to drive to work. 15 minutes back home.

That's how I "read." Audio books while driving in my car instead of incessant music.

Don't get me wrong -- music's good, too. Just, for me, not incessantly.

[frankthetank]

I must be a slow reader! I started that Diamond book at B&N but was too cheap to buy it.

[Dr. Ofellati]

No interest, and it wouldn't inform on the current thread.

Why waste time debating with someone who isn't interested in learning about the subject of the debate?

Ah Ludi, queen of the Climate Change Cult, always with the spin, eh? I don't waste time on tangents, which is what the suggested reference would be. You read it. If you've read it, reread it.

[americandream]

Up to your old tricks again Olefatti!

[Ludi]

Ah Ludi, queen of the Climate Change Cult,

Ooo, I like that! Thanks!