05 Feb 19
The post that was quoted here has been removedFrom the article you cited:
“The great dying of the indigenous peoples of the Americas resulted in a human-driven global impact on the Earth system in the two centuries prior to the Industrial Revolution,” wrote the UCL team of Alexander Koch, Chris Brierley, Mark Maslin and Simon Lewis.
The drop in temperature during this period is known as the “Little Ice Age”, a time when the River Thames in London would regularly freeze over, snowstorms were common in Portugal and disrupted agriculture caused famines in several European countries.
The article didn't say it was the sole cause, but it certainly is alleging a cause and effect relationship.
The post that was quoted here has been removedHere's my basic problem with the claim:
The thesis of most proponents of AGW (of which I consider myself included) is that we have contributed to greenhouse gas increases in the atmosphere since the industrial revolution by steadily increasing greenhouse gas emissions.
Everyone agrees that throughout history, there have been natural fluctuations and cycles in global temperatures, but the thesis is that natural cycles would not easily explain the share spike (inconsistent, but statistically significant) in the past ~ 200 years.
Okay, fair enough.
But the AGW theory doesn't propose to explain every natural ebb and flow in temperatures throughout human history by pointing to human behaviors. This would be impossible, as there were climate cycles long before humans showed up on the planet.
I know of no thesis that there was significant AGW before the industrial revolution and certainly I don't think anyone would be able to show a direct relationship between human pre-industrial farming and foresting activities and global temperatures.
If you know of a study that does this sort of analysis, please point it out. But I know of none.
To explain the little ice age as being (even partially) attributable to large scale human death in NA would require one to show that the propagation of those human activities in the first place caused some warming that was partially wiped away by the genocide of the NA and consequent decrease in activity. Has this warming been shown? Does it correspond to increase in human pre-industrial activities of farming?
Without a comprehensive study showing a causal relationship between human pre-industrial activities and global climate, this seems to me like a wild stab in the dark - an effect begging for a guess at its cause.
My understanding is that the general consensus is that we don't know precisely why we get temperature peaks and troughs but that the natural cycle wouldn't explain the peak we're seeing now without greenhouse gas emissions. This does not support the tying of the little ice age to the genocide of the pre-industrial NAs.
@sh76 saidA global synthesis of over 500 paleoclimate records shows that 1577–1694 CE is the only period of significant global cooling within the past two millennia, and the only part of the Little Ice Age (LIA) that was global in extent (Fig. 5B from, Neukom et al., 2014).
Here's my basic problem with the claim:
The thesis of most proponents of AGW (of which I consider myself included) is that we have contributed to greenhouse gas increases in the atmosphere since the industrial revolution by steadily increasing greenhouse gas emissions.
Everyone agrees that throughout history, there have been natural fluctuations and cycles in global temper ...[text shortened]... ns. This does not support the tying of the little ice age to the genocide of the pre-industrial NAs.
https://www.sciencedirect.com/science/article/pii/S0277379118307261 at 7.2
Their analysis is considerably more sophisticated and deeper in time than you are suggesting:
o more fully understand the changes to the Earth system in the 1500s and 1600s we compile data from 1000 CE to 1800 CE for (A) the atmospheric CO2 concentration, (B) global surface air temperatures, and three potential drivers of these changes, (C) Total Solar Irradiation, (D) volcanic eruptions, and land carbon fluxes, as (E) the carbon flux to the land, (F) LUC in the Americas, and (G) LUC in the rest of the world (Fig. 5). Beyond visual comparisons that imply a strong role for LUC in the Americas, we can also assess the contribution of each of the potential drivers of changes in atmospheric CO2 and global surface air temperature by calculating their radiative forcing impact on air temperatures.
06 Feb 19
@sh76 saidYep, and now these same people want to "cool" down the planet again.
Wow.
Attributing the Little Ice Age to the genocide of Naive Americans?
Seems like a group desperate to find a cause of every effect.
Something things just happen, fellas. You can'y always prove the reasons for every phenomenon.
Hold on to your hats everyone and watch your back.