Columbus blamed for Little Ice Age | Hacker News Reader

Columbus blamed for Little Ice Age

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77 pointspwg42 comments

The must-read book for the context is 1491, by Charles C. Mann [1]. The main point is that pre-Columbian America was much more densely populated than previously thought, with the Native Americans managing a good deal of the ecosystem. European contact brought in diseases (mainly smallpox) that killed off the vast majority of the inhabitants, with momentous consequences for the ecosystem (e.g. the extreme proliferation of bison and passenger pigeon). But really read the book, it's very well written, based on the latest research, and quite enlightening.

[1]http://www.amazon.com/1491-Revelations-Americas-Before-Colum...

Interesting theory except, as others have pointed out, the Little Ice Age started perhaps 2 centuries before Columbus. The North Atlantic ice pack was growing by 1250. In 1315 the European climate changed permanently for the worse with with heavy rainfall and a permanent drop in temperatures. The deepest part of the Little Ice Age occurred with the Maunder Minimum where sunspots virtually disappeared (1645-1715). Unfortunately, there were no sunspot observations for the 13th and 14th centuries to to show whether the start of the Little Ice Age occurred with a solar minimum.

You're confusing the end of the Medieval Warm Period with the start of the Little Ice Age.

During the Medieval Warm Period from 950-1250 sea ice was temporarily reduced, allowing the colonization of Greenland. This is not necessarily related to the Little Ice Age from 1550-1850.

It's really a matter of deciding when is the start of the Little Ice Age. http://en.wikipedia.org/wiki/Little_Ice_Age Some put it at the end of the medieval warn period, others hundreds of years later. I favor 1315, because over the period of a few years the climate of Europe tanked for hundreds of years. Of course a 1315 date argues for the cause being a long solar minimum and not reforestation.

My opinion was greatly influenced by Brian Fagan: The Little Ice Age, http://www.amazon.com/Little-Ice-Age-Climate-1300-1850/dp/04....

It's really just a matter of basic honesty to admit the consensus dating (1550-) up front. The 11 critical comments you're following from the linked article all fail to do this.

> This new growth could have soaked up between 2 billion and 17 billion tons of carbon dioxide from the air.

That seems like a lot of uncertainty.

I am not sure you are allowed to question climate science like that. But it does make me wonder about large tree planting projects as an approach to climate change. Although I've heard there are problems with water tables in China where they have conducted green belt strategies to limit growing deserts.

edit: [1]http://en.wikipedia.org/wiki/Green_Wall_of_China#Problems

edit2: -2 wow, anyone care to explain? Sarcasm not permitted?

Understanding the whims of karma change on HN comment are not worth pondering or worrying about, much less commenting about (which usually just ends up making things worse).

There also seems to be an over-corrective quality. As I am now on 20 points, but people can't see that (until this comment) and therefore I think some people presume I am only just back from negative and give me an upvote to pad the figures against the humourless. Strange indeed. But you are right regarding what usually happens: a complaint can often lead from burnt whiskers to a smoking crater.

Generally, sarcasm is to be avoided. It tends to downgrade the discussion and many people will down vote comments they agree with if they dislike the tone. It's often argued that this was even the original intent of voting and doing anything else is the path to Reddit.

In response to Hisoka: it looks like your "Did Google pay you to say this?" comment got your account auto-killed.

At some point, someone is going to have to put serious money into desalination plants.

Surely we've got enough places having droughts that our control over nature will have us putting up massive water pipelines around the world. They'll need redundant desalination and cleansing plants.

Anyone know what to do with all the material removed?

I get the feeling we'll need to dump it back into the ocean in a controlled way. Seem to remember that from some reading I was doing years ago. I remember the article said a good test place would be the coast of Africa so farming didn't take too much water from the Serengeti messing up the wildlife.

You don't seem to have a good understanding on the difference between what is permitted and what is discouraged.

Questioning of all science is encouraged. Blind denialism is discouraged because it is idiotic, but permitted.

Amusingly, Mr. Loudmax, you are being far more rude, and therefore deserving of a downvote, than I ever was. I believe the word "permitted" with regard to social sanction (HN votes) has a greater range of meaning than you are permitting here. And even if what you say were true, there is no blind "denialism" in my post either. In fact the sentence in question could have been written by someone on either side of the climate debate. Only a humourless po-faced person, the type on a crusade and using ridiculous words like "denialism", would downvote it.

Yes; especially given this comment on the article (by Bo Higgs):

This article gives too much coverage to the 'Politically Correct' piece of crap by this clown, Richard Nevle.

The "Little Ice Age" began long BEFORE 1492. The Pope in Rome sent Columbus a letter (after 1492) asking for Columbus to investigate, "what had happened to the Bishop of Greenland," because Rome had not had any letters from Greenland for many years. N.B. -- There were so many Catholics living in Greenland, that the Pope appointed a Bishop to live there.

The Middle Ages Warm Period had ended decades before, and could no longer sustain the European-style agrarian life-style.

Also, bear in mind that post-1500, World exploration meant required an exponential increase in wooden ships, both in number and in size. As a result, not only did population increase, but so did de-forestation. Indeed, perhaps the main export of the American Colonies was LUMBER. Even the export of tobacco,and then cotton required de-forestation. By 1608, the well-known, but un-mapped 'Northwest Passage' had frozen over to such an extent that Henry Hudson was un-able to complete his mapping. Re-forestation must have been exceedingly rapid to effect the entire Earth in such a short time.

Richard Nevle is proof of the adage that, "If the only tool you have is a Grant to prove A.G.W.(tm), then everything in the result of A.G.W.(tm)"

Reprinting a comment from another page, particularly a comment full of abuse (politically correct piece of crap? clown?), inaccuracies, and conspiracist wonderings, is not really worthy of HN.

I'll just point out the first glaring issue about the only fact that the comment even mentions: the "Little Ice Age," though somewhat ambiguously defined, is usually taken to mean the era from the mid sixteenth century to the nineteenth.

The text of http://en.wikipedia.org/wiki/History_of_Greenland#The_demise... implies that the Little Ice Age is taken to have started earlier in Greenland, although this is contradicted by the graph next to it.

There's actually some level of debate about whether the Little Ice Age even existed as a global event, as opposed to several coincidental regional climatic changes. So it's a bit messy (and if it didn't actually exist globally, it would suggest that the article is explaining something that never happened).

I'm not sure of whether there's any scientific consensus on it, however. NASA does suggest the Little Ice Age started in 1550, though.

and another uncertainty is the deforestation these Europeans then made to build their new homes on the other continent. Considering how the Buffalos almost died out they weren't that ecofriendly ..

Wow, so in the 1400's we were already on the way to anthropogenic global warming, essentially!

Um, no? Did you read the article? It is talking about a massive reforestation event due to the Native Americans dying off. This is the exact opposite of anthropogenic global warming.

He read the article. He's implying that we were on the way to anthropogenic global warming, and then Columbus and those who followed him inadvertently put a stop to it.

I think he's saying that the deforestation that had been happening before must therefore have been contributing to global warming, if ending it contributed to global cooling.

Reforestation implies prior deforestation. That the death of any number of people in the 1400's made the climate change is essentially the meaning of anthropogenic climate change. So yeah, kid, I read the article.

The size of California is 423970 square kilometres. At the higher end of the population estimate (80 million), and assuming complete annihilation of the population, that's 0.53 hectares (or 1.3 acres) of constant deforestation for every man, woman and child.

This is over North and South America and I have seen estimates that disease wiped out over 80% of the native population. Some areas lost well over 95% of the population others much less so. But, disease tends to spread more rapidly though more densely populated areas, so it’s effect is going to be concentrated on farming communities. And those areas where early europeans spent most of their time aka South America.

Still, it's hard to estimate what percentage of those people where farmers, but based on current results from slash and burn agriculture in South America sustained clearing of 10+ acres per person would not be unreasonable considering the crops and methods used during that period. Also, even non farmers are going to start a fair amount of forest fires simply by cooking food. So over all their numbers seem far more credible than you might expect.

What's being described is not slash and burn agriculture in the way it's practiced now, or "deforestation", but a regular seasonal burn-off of prairie or savanna. It prevented trees from taking hold in very wide areas. The book 1491 has good pointers in its bibliography to reputable sources about pre-Columbian grassland burns.

We're talking about the Amazon basin, much of which was probably farmland prior to European influence. According to the archeological record, that region may have grown enough food to support millions of people. That's a lot of land, which then converted into dense rainforest.

For an older, non popsci article treating the topic, check out this one from 2006, "Evidence for the Postconquest Demographic Collapse of the Americas in Historical CO2 Levels":

http://journals.ametsoc.org/doi/full/10.1175/EI157.1

Biological weapons appear to trump any other sort of manmade or natural disaster, short of a killer asteroid.

it is more like the whole humanity is continuously trying to win a Darwin Award. One can imagine galactic version of http://www.darwinawards.com/ where aliens laughing at human race frantically trying to once more increase [under the "domestic /independence" sauce] production of fossil fuels instead of just harvesting free solar and wind energy. Stupid as stupid does.

Interesting, so to extrapolate from this theory, we could halt and even reverse global warming by killing off tons of people. Seems obvious in hindsight.

I read somewhere that the US may actually accidentally come close to its Kyoto targets because of the recession. So yes. Nuclear as your argument may be, you are probably correct. =P

So how much forestation would be required to reverse a significant part of the effect of the industrial revolution? Lets say the CO2 emitted in the last 30 years.

Would there be enough vacant area on earth to handle such an amount of forestation? In Europe, I could only imagine a significant reforestation if our agriculture becomes much more efficient.

Please correct me if I'm wrong, but over its life and decomposition, isn't a tree carbon neutral? While growing, trees basically absorb carbon, and when they decay that carbon is released back into the air. Therefore, planting more trees will not reduce carbon in the long term.

Kinda, but:

A tree can live for hundreds of years, which is long enough for many changes to take place.

Not all trees that die decompose completely. Coal and oil are examples of long term sequestration. A lot of the carbon in coal and oil would still be buried if not for meddling humans.

Yes, but while the trees are alive and before they have completely decomposed they are sequestering the carbon. It is more useful to consider the population of trees in this case. While the population of trees is higher, the amount of carbon trapped in trees is higher and therefore the amount of carbon in the atmosphere is lower. This effect would have ended when the population of trees declined to its pre-Columbian levels.

You're correct, but only if the tree's entire carbon store is released to the atmosphere, such as by being burned. Not all of the tree is able to decay and release its carbon. The portion of the organic matter that fell to the forest floor, was covered by other organic matter, stayed there for a long time and eventually becomes coal or oil. In other words, you can end up storing a lot of carbon in the soil.

I suppose one good way to sequester carbon is to plant trees then cut them down at maturity and build durable buildings out of them.

I suppose one good way to sequester carbon is to plant trees then cut them down at maturity and build durable buildings out of them

Or dump the trunks into any oxygen starved bog.

Or ship them to the northern parts of the world and bury them in the shallow permafrost layer.

Except both of those hold the risk of a sudden return of massive amounts of CO2 to the air due to some unforeseen (fire!) event.

The most low risk is probably to turn them into charcoal, mix that charcoal into the soil they came from and plant new trees there. As long as some of the carbon is still in the soil by the time you repeat the process, you have a net gain of CO2 sequestration.

Speaking as a layman..this all sounds a bit far-fetched. A drop of 80 million people in the Americas then is as nothing compared to what's happened with world populations in the 19th and 20th centuries. Despite a growth by billions we're still debating if climate change is definitely happening today. Maybe I'm just becoming more cynical as I get older

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