WI: Native Americans never crossed over from Asia

[jahenders]

I don't think so -- I was trying to convey some of those butterflies.

The OP involved an empty America, but aren't you forgetting the butterflies of a empty America on European history and civilization

 

[Napoleonrules]

Yes all 70 of them. I didn't say they'd go off and start some big civilization, I said they could wander elsewhere and that they didn't have to just settle in Siberia. That was my argument that they could wander elsewhere and they could of. The fact that there were 70 of them just wants it easier for them to wander elsewhere. So yes all 70 of them.



Pretty much everywhere, but particularly the Amazons



I am not a scientist well versed in this theory so I can't argue against what you say Derek, it is easily possible that I just misconnected the argument of the scientist who discussed how Humans started global warming. But I'd like to clarify that by lots of trees I don't mean a forest, I mean swathes of forests. The Americas were host to great civilizations of large populations that had a considerable affect on their climate. I forget the exact now but millions, maybe its tens of millions, of trees were estimated to have been lost to American populations before the arrival of the Europeans which devastated their populations.

Derek is technically correct that the highest level of CO2 does correspond to the most forested time period but he's getting cause and effect wrong. The high CO2 caused the forests; it's not hat the forests were there and the CO2 still happened, the CO2 was first and caused the forests to be able to grow to a massive extent. Same thing WOULD happen today but humans are still cutting down all those trees and not allowing them to spread as they otherwise would. And we've selected for trees less diverse and not as big as they would have had in those earlier geologic timespans.

The Great Plains would have had more scattered forests than they did IOTL, but it wouldn't be one huge forested area like the east or northwestern US coasts. A lot of it was the result of human management, human caused forest fires, and the intentional making the environment good for buffalo (actually bison, not a buffalo).

What I'm curious about, and haven't done research on is- would OTL extinct large mammals bigger than a bison, have survived in an ATL without humans in the New World? Would we have had mammoth and mastadon, and maybe in certain places of North America like the Great Plains or Great Basin or the pampas of Argentina a decendent from them that paralleled the evolution of Africa's elephants? Anyone know? I'll start researching.

 

[Derek Pullem]

Derek is technically correct that the highest level of CO2 does correspond to the most forested time period but he's getting cause and effect wrong. The high CO2 caused the forests; it's not hat the forests were there and the CO2 still happened, the CO2 was first and caused the forests to be able to grow to a massive extent. Same thing WOULD happen today but humans are still cutting down all those trees and not allowing them to spread as they otherwise would. And we've selected for trees less diverse and not as big as they would have had in those earlier geologic timespans.

The Great Plains would have had more scattered forests than they did IOTL, but it wouldn't be one huge forested area like the east or northwestern US coasts. A lot of it was the result of human management, human caused forest fires, and the intentional making the environment good for buffalo (actually bison, not a buffalo).

What I'm curious about, and haven't done research on is- would OTL extinct large mammals bigger than a bison, have survived in an ATL without humans in the New World? Would we have had mammoth and mastadon, and maybe in certain places of North America like the Great Plains or Great Basin or the pampas of Argentina a decendent from them that paralleled the evolution of Africa's elephants? Anyone know? I'll start researching.

I wasn't making the argument that lots of trees = high CO2. What I was taking issue with was the assumption that the absence of a relatively small number of Amerindians could impact the climate so quickly (hundreds / low thousands of years) as to cause glaciation in Europe!

High CO2 and forestation are not directly linked. One tends to offset the other but other factors as you rightly point out can dominate.

 

[Gurroruo]

What I was taking issue with was the assumption that the absence of a relatively small number of Amerindians could impact the climate so quickly (hundreds / low thousands of years) as to cause glaciation in Europe!

I agree that relatively the population of the Americas is small at ~50 million PreCom, but that's simply because Asia is a powerhouse of population. Europe and Africa not so much, but they do stomp over the Americas. Meanwhile the Americas only beat Australia which is a majority desert island and Antarctica, which is a permafrost island. And it wouldn't be quick, it would be over the course of 20,000 years.

 

[Napoleonrules]

I wasn't making the argument that lots of trees = high CO2. What I was taking issue with was the assumption that the absence of a relatively small number of Amerindians could impact the climate so quickly (hundreds / low thousands of years) as to cause glaciation in Europe!

High CO2 and forestation are not directly linked. One tends to offset the other but other factors as you rightly point out can dominate.

It appears to me that you may be someone who does not believe in human ability to affect the climate, such as our our current period of global climate change which is MANMADE. In which case it is useless to argue science with you.

 

[Mr.brightside]

I wasn't making the argument that lots of trees = high CO2. What I was taking issue with was the assumption that the absence of a relatively small number of Amerindians could impact the climate so quickly (hundreds / low thousands of years) as to cause glaciation in Europe!

High CO2 and forestation are not directly linked. One tends to offset the other but other factors as you rightly point out can dominate.

It Really doesn't take that many people to clear large areas of forest. It happened in China and Europe pretty early on.

CO2 levels are right up there with changes in orbit in influence on global climate. The changes are relatively quick but the effects are also minor on a geologic scale. Things like the little ice age and the Medieval warming period are just blimps on the geologic scale and yet drastically alter human history.

Also Europe has never stopped being glaciated. Remember folk we are still in a Ice Age.

 

[Mr.brightside]

It appears to me that you may be someone who does not believe in human ability to affect the climate, such as our our current period of global climate change which is MANMADE. In which case it is useless to argue science with you.

I didn't really get that from him. It's fairly new science so I'd would take it easy.

 

[Derek Pullem]

It appears to me that you may be someone who does not believe in human ability to affect the climate, such as our our current period of global climate change which is MANMADE. In which case it is useless to argue science with you.

As someone with a Chemical Engineering degree I am well aware of the science of Global Warming.

I'm also well aware of a large number of "environmentalists" with no practical training in science making all kinds of unsubstantiated claims on what will happen.

We know global warming (as a mechanism related to higher CO2 levels) exists. What we do not know is how our intervention with the environment impacts global warming in detail. We also have very limited understanding of how the Earth's ecosystem (esp. oceans and ice caps) reacts to changes in CO2.

In the long term the path is clear - in a short term (and the suggested deforestation of North America from c 12000 BCE is actually pretty short term giving the numbers of people and their ability to impact the environment) it's much more confused.

The people who are "useless to argue with" are not scientists and engineers - we know that using less of a finite resources (or at least one that cannot be replenished on a reasonable time scale) is a sensible approach. The problem lies with the Global Warming Evangelists who believe that coal is bad, oil is bad, nuclear is bad and that solar and wind/wave will be the way forward. Like most unscientific environmentalist utopias that works - so long as we revert to a pre-industrial life style and/or 80% of the world population is "culled"

 

[Derek Pullem]

It Really doesn't take that many people to clear large areas of forest. It happened in China and Europe pretty early on.

CO2 levels are right up there with changes in orbit in influence on global climate. The changes are relatively quick but the effects are also minor on a geologic scale. Things like the little ice age and the Medieval warming period are just blimps on the geologic scale and yet drastically alter human history.

Also Europe has never stopped being glaciated. Remember folk we are still in a Ice Age.

True - but CO2 levels in the atmosphere actually fell from 10000 BCE to 5000 BCE. Which if we accepted the no settlers in America =more European glaciation idea is strange as the settlers appeared to be chopping down those tress and the CO2 levels were falling IRL.

Global warming exists - our understanding of the detail doesn't

 

[Mr.brightside]

True - but CO2 levels in the atmosphere actually fell from 10000 BCE to 5000 BCE. Which if we accepted the no settlers in America =more European glaciation idea is strange as the settlers appeared to be chopping down those tress and the CO2 levels were falling IRL.

Global warming exists - our understanding of the detail doesn't

Did they fall. Could you provide a link?

Also maize wasn't domesticated until around 6000 BCE so the fall in CO2 pior is unrelated. More likely has something to do with newly exposed rock absorbing CO2.