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Bill White

Member

Registered: 2001-09-09

Posts: 2,114

Re: Did we terraform Earth? - A new study

This article discusses new data that suggests that beginning 8000 years ago, human activities such as agriculture and cutting and burning forests added to the global CO2 and thereby averted a predicted cooling trend.

Beginning 8,000 years ago, atmospheric levels of carbon dioxide began to rise as humans started clearing forests, planting crops and raising livestock, a scientist said Tuesday. Methane levels started increasing 3,000 years later.

The combined increases of the two greenhouse gases implicated in global warming were slow but steady and staved off what should have been a period of significant natural cooling, said Bill Ruddiman, emeritus professor at the University of Virginia.

 
The research studied 400,000 years of South Pole ice cores and the claimed result is:

The changes also disrupted regular patterns that dominated the 400,000 years of atmospheric history that scientists have teased from samples of ancient ice.

"You have 395,000 years of history, which sets some rules, and 5,000 years that break those rules," Ruddiman said.

A BBC link on the same study. The BBC story is the better of the two, IMHO, with greater depth.

Palomar

Member

From: USA

Registered: 2002-05-30

Posts: 9,734

Re: Did we terraform Earth? - A new study

*Yes, I guess...insofar as human activity has, to some extent (occasionally greater, occasionally lesser), made alterations in surroundings upon moving out of the ancestral cradle (Africa) and pushing onward into new areas.  Palm trees are definitely not native to the Chihuahuan Desert (where I live), but they are planted here for their exotic appearance (they are especially popular in parks and for landscaping schemes of professional or government office buildings).

But flora and fauna predate mankind (in the evolutionary scheme of things) by millions of years. 

I'm not sure "terraforming" is the right word in this context, i.e. that it "fits" with the same concept as plans for Marsian terraforming...because I don't think it does.  Earth's has been a mix of -mostly- natural development, with some human interference (unintentional or otherwise)...if Mars is terraformed, that will mostly be the result of deliberately applied manipulation (non-natural to it).

--Cindy

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We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

Cobra Commander

Member

From: The outskirts of Detroit.

Registered: 2002-04-09

Posts: 3,039

Re: Did we terraform Earth? - A new study

Just a couple thoughts here. First, I am wary of conclusions drawn about 400,000 years of history based on data "teased from samples of ancient ice." What I call the 7-11 factor comes into play here. In short, we don't know with certainty who robbed the 7-11 last Friday night, despite witnesses and cameras, so how can we be so sure about anything that happened before recorded history? Something to keep in mind when some academic is spewing his findings as though they are undeniable truth.

But more on the subject, well said Cindy. But I can never leave well enough alone, so... of course humans have added CO2 to the enviroment, we exhale the stuff. All animate life kicks out CO2. The question is whether human activity contributed to such an extent as to "avert a cooling trend."
A trend predicted based on unproven models fed with incomplete data, I might add. It's possible, though I don't recall seeing much evidence of Neanderthals burning down forests on a large scale or doing much of anything that would have a greater impact than the activity of any other large mammal.  This strikes me as a study based more on pre-conceived ideas of what certain people would like to prove rather than actual scientific data. Still, maybe...

But is it terraforming? I would give an emphatic no. At least to me, terraforming requires intent, the conscious decision to alter the enviroment on a large scale. Not only that but it must be a change that makes the enviroment more conducive to life. We can change the climate significantly by dropping a few nukes, but is that terraforming?

To be real nitpicky, you can't terraform Earth because it's already Terra. The form one tries to copy, but we'll let that one go...

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Build a man a fire and he's warm for a day. Set a man on fire and he's warm for the rest of his life.

Mars_B4_Moon

Member

Registered: 2006-03-23

Posts: 9,385

Re: Did we terraform Earth? - A new study

Evidence of Ice Age human migrations from China to the Americas and Japan
https://www.eurekalert.org/news-releases/988195

I thought I would bump an old thread since 'Paleoclimatology' has become part of active discussion

a picture of the old climate jigsaw puzzle

Record-shattering 2.7-million-year-old ice core reveals start of the ice ages
https://www.science.org/content/article … t-ice-ages
Clues to ancient atmosphere found in bubbles trapped in Antarctic samples

NOAA/WDS Paleoclimatology - EPICA Dome C Ice Core Terminations I and II Air Isotopes and CO2 Data
https://www.ncei.noaa.gov/access/metada … core-15077
This archived Paleoclimatology Study is available from the NOAA National Centers for Environmental Information (NCEI), under the World Data Service (WDS) for Paleoclimatology.

Greenland ice cores reveal warm climate of the past
https://nbi.ku.dk/english/news/news13/g … -the-past/

What do ice cores reveal about the past?
https://nsidc.org/learn/ask-scientist/c … te-history

NOAA/WDS Paleoclimatology - North GRIP Ice Core Last Glacial d15N and Temperature Reconstruction
https://www.ncei.noaa.gov/access/metada … core-24371

Last edited by Mars_B4_Moon (2023-05-10 03:14:37)