Article on little ice age possible cause

[Masquernom]

The authors conclude that when Europeans arrived in the Americas, disease killed ~ 90% of the native population. The agricultural land returned to forest. The forest absorbed CO2 from the atmosphere, and it led to the little ice age of 1610. Also known as the year without a summer.


Trying to post a link to the study;

https://www.sciencedirect.com/science/article/pii/S0277379118307261#!

 

[ERD50]

I did see an article on that. Interesting study.

Related to that:

https://www.princeton.edu/news/2018...od-low-carbon-fuel-poised-harm-global-forests

Europe’s decision to promote the use of wood as a “renewable fuel” will likely greatly increase Europe’s greenhouse gas emissions and cause severe harm to the world’s forests, according to a new comment paper published in Nature Communications.

European officials agreed on final language for a renewable energy directive earlier this summer that will almost double Europe’s use of renewable energy by 2030. Against the advice of 800 scientists, the directive now treats wood as a low-carbon fuel, meaning that whole trees or large portions of trees can be cut down deliberately to burn.


Although wood is renewable, cutting down and burning wood for energy increases carbon in the atmosphere for decades to hundreds of years depending on a number of factors, the researchers explained. Bioenergy use in this form takes carbon that would otherwise remain stored in a forest and puts it into the atmosphere. Because of various inefficiencies in both the harvesting and burning process, the result is that far more carbon is emitted up smokestacks and into the air per kilowatt hour of electricity or heat than burning fossil fuels, the authors explained.

Seems pretty clear that burning wood as a renewable source is going to do harm. In the mean time, the US has lowered their carbon output through switching to more Natural Gas (still fossil fuel, but less carbon relative to energy output).

And these Euro nations signed the Paris Accord! Lotta good that does!

-ERD50

 

[Music Lover]

So, now we are to believe that the natives were all farmers with vast extensive tracts of farmland, so vast that it affected the climate...rather than tribes of hunter gatherers as we've been told for decades??

 

[braumeister]

So, now we are to believe that the natives were all farmers with vast extensive tracts of farmland, so vast that it affected the climate...rather than tribes of hunter gatherers as we've been told for decades??

There was extensive farming in some parts of North America before European contact, but I still think volcanic eruptions are the more likely cause of the little ice age.

 

[audreyh1]

So, now we are to believe that the natives were all farmers with vast extensive tracts of farmland, so vast that it affected the climate...rather than tribes of hunter gatherers as we've been told for decades??

Yeah, I’m finding that hard to swallow. Yes. There were farming communities, but the native population density was super low not counting central and southern Mexico.

I also figure it’s gotta be volcanic eruptions.

 

[timo2]

Yeah, I’m finding that hard to swallow. Yes. There were farming communities, but the native population density was super low not counting central and southern Mexico.

I also figure it’s gotta be volcanic eruptions.

But they are counting central and southern Mexico, if I read the article correctly.

 

[Music Lover]

There was extensive farming in some parts of North America before European contact, but I still think volcanic eruptions are the more likely cause of the little ice age.

The Little Ice Age also happened at the same time as the Maunder Minimum...a time when sunspot activity was very low. Low sunspot activity is often linked to cooler temperatures.

 

[ERD50]

So, now we are to believe that the natives were all farmers with vast extensive tracts of farmland, so vast that it affected the climate...rather than tribes of hunter gatherers as we've been told for decades??

That was my reaction as well. But then again, a lot of the things I was told for decades were wrong too!

-ERD50

 

[Music Lover]

That was my reaction as well. But then again, a lot of the things I was told for decades were wrong too!

-ERD50

A lot of things we are told today are wrong...and it's even worse because it seems to be deliberate and not by error.

 

[timo2]

how about the proverbial and now disgraced term 'synergy' of volcanic eruptions, sunspot patterns, and the aforementioned temporary loss of cultivated land in the western hemisphere? Stuff happens.

 

[Sunset]

So, now we are to believe that the natives were all farmers with vast extensive tracts of farmland, so vast that it affected the climate...rather than tribes of hunter gatherers as we've been told for decades??

That and the giant herds of buffalo each tribe kept for milking, that they would let out each day to roam the plains

 

[I was misinformed]

The authors conclude that when Europeans arrived in the Americas, disease killed ~ 90% of the native population. The agricultural land returned to forest. The forest absorbed CO2 from the atmosphere, and it led to the little ice age of 1610. Also known as the year without a summer.

Thanks for posting about this interesting study.

Note that the "Year Without a Summer" normally refers to the single year 1816 which had an exceptionally cold summer, at least in many parts of the extratropical northern hemisphere. This year is near the end of the Little Ice Age (LIE) as often defined, but the cold summer in 1816 is generally (and quite plausibly) explained as resulting primarily from the global atmospheric effects of the explosive eruption of Mt. Tambora in 1815.

The basic cause or causes of the LIE are still not definitively understood. The issues raised in this new paper might be usefully divided into two parts. First the authors find ice core data suggest there was a decrease of atmospheric CO2 concentration of about 7-10 ppm around the end of the 1500's and the first 2-3 decades after 1600. How did this occur? The authors try to rule out other natural causes and propose this novel idea of reforestation of the Americas. I am not sure how plausible their estimates for the amount of reforestation are, and I would imagine there is a great deal of uncertainty concerning this aspect. I am also not clear on how persuasive their ruling out natural causes is.

The second (essentially independent) issue is then whether the 7-10 ppm post-1600 decrease in atmospheric CO2 could have driven the climate changes seen over the extended LIE period? The answer is likely that the CO2 change is too small to account for the LIE by itself and I think the authors are just positing the reforestation (and consequent CO2 decrease) as one contributor along with solar changes and possibly volcanism to the LIE global cooling. As a crude comparison we have seen the post-industrial atmospheric CO2 increase by ~130 ppm (from ~280 to ~410 ppm today) and this has apparently driven an increase in global mean temperatures of at most 1 degree C.

 

[Masquernom]

Yes, you're correct, the year without a summer was 1816. Has nothing to do with this article.

 

[Koogie]

Agree with most posters so far. This doesn't quite pass the sniff test.

Nice to see critical thinking is still a common skill.... not something you'd believe if you just stick to reading the news...