Except that the land that is uncovered is not very good farmland. All the value of the nutrients went up in smoke with the trees and plants. You can only get a few years out of it before you have to go burn down some more forest, and leave empty wasteland in your wake.
I have seen this several times. I do have to ask - can farmland not be remediated? We have farmland in the USA that has been in continuous use for several hundred years now. It hasn’t “run out” of nutrients - various fertilizers can, as I understand it, add the minerals and nitrates that get depleted with each years’ crops.
The land in the US has soil that sometimes goes down for hundreds of feet. We lose several inches a year, but it still can last for hundreds of years.
The land under a rain forest is not so deep. The soil is not as well established, it is less rich in nutrients to start with, and will easily erode.
You could cultivate the fields more carefully and get them to last much longer or even indefinitely, but that is a more expensive proposition than just burning down another few hundred acres of rain forest when your current fields die out.
In the US, we took grasslands, and then we started growing grass on them. That’s all most of our crops are is modified grass. Going from rain forest to farm is a bit more of a shock to the system.
To an extent, but only to an extent.
And yes, it did run out for a while, even in parts the USA. The historical record is pretty clear that not all land is suitable as farmland, even if some of that land can be used as such for temporary periods. And even when there is good farmland, profitable crops and sustainable crops are not always the same thing.
Solutions to this problem…
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Get people to stop burning/cutting the amazon rain forest down.
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Everyone, everywhere should plant a tree.
Not that everyone planting a tree would be a bad thing, but you’d need a heck of a lot more than one tree per person.
The problem is is that the Amazon resides in countries that we cannot just make do what we want. They aren’t burning it for fun, they are burning it in order to grow food and cash crops.
And everyone needs to plant more than just one tree. The emerald ash borer alone killed off about as many trees as there are people in the US.
And in Africa and Southeast Asia, forests are being clear-cut or burned for rubber and palm oil plantations.
If the Amazon was totally burned, we’d find some tribes and civilizations that we weren’t previously aware of (with interesting social and medical consequences) but honestly, it would produce so much smoke, the sun would be blotted out before we all died from anoxia.
On a lighter note, all hail Plankton!
From Forbes: Why Everything They Say About The Amazon, Including That It’s The “Lungs Of The World,” Is Wrong
I’m interested in 2 factual claims that this guy makes.
[ol]
[li]The claim that the Amazon is “the lungs of the world” is extremely overstated, because while the Amazon produces an enormous amount of oxygen, it also uses an enormous amount, and the net impact is insignificant.[/li][li]The level of fires currently burning in the Amazon is not significantly higher than the recent average levels.[/li][/ol]
What’s the Straight Dope on these claims?
Phytoplankton contribute 50-70%, and we are screwing that up.
For the first claim, I can at least agree that most of Earth’s oxygen comes from phytoplankton, not trees. Trees are, roughly speaking, a neat way to temporarily store carbon. Trees have a respiration cycle, the same as we do - they inhale carbon dioxide during the day to help with photosynthesis, and exhale carbon dioxide at night. This isn’t a 1:1 ratio, though; a lot of carbon is sequestered as the tree grows.
Of course, we’re not just talking about trees when we talk about the Amazon rainforest. There’s a whole lot of other things going on that can negate the oxygen surplus. That said, losing the Amazon rainforest would still have a huge impact on the climate and carbon dioxide levels world-wide.
For the second claim: yes and no.
The National Institute for Space Research (this is the Brazil agency) says that there is an 83% increase in the number of fires.
The National Aeronautics and Space Administration (in the US) says that the overall fire activity in the Amazon basin is slightly below average this year.
The answer depends on the scope: do you take the Amazon as a whole, which is more than just what is contained in Brazil? Or do you look just at Brazil, and wonder what could cause an 83% uptick?
Amazon rainforest contributes about 5.5% of world oxygen.
Depends what you mean by recent. This year’s fires are alot more than last year’s but well below what they were 10-15 years ago.
https://en.wikipedia.org/wiki/Deforestation_of_the_Amazon_rainforest
Current annual rates are less than a half of what existed during the late 70’s through the early 21st century. I do not know what percentage being burned is virgin rain forest and how much is previously burned scrub brush and grasslands.
Can we blame the Trump -China tariff tiff for some of this? (same cite)
For #1 it really depends on how you want to play the numbers.
The Amazon is historically been a good carbon sink, but due to reduced area that is trending to not be true. But historically the claims that:
So it is partially true, mostly due to tree growth and sequestration.
While the data isn’t perfect for oxygen production outside of the local area, the Amazon is about a wash, and the Boreal forests of the North are far more significant if you don’t define “sharing” as sharing to other geographic areas of the world.
Consider that in per 100 acres of 100% forest in Minneapolis offsets oxygen consumption of 19 people per year; where that same 100 acres in Calgary would offset 28 people. As noted Cyanobacteria and Plankton produce more than 2/3 of the worlds O2.
This this claim is false:
Net O2 is when carbon is being locked away in a carbon pool that turns over very slowly, which doesn’t happen much in the Amazon. That said; we have evidence that deforestation is creating more drought which in turn causes more fires and more deforestation in the Amazon. There are many reasons to help Brazilians and other South Americans protect the rain forest but yes this 20% number is a very pervasive and incorrect urban legend.
Unfortunately as pointed out in the article you posted using this type of urban myth does pose some barriers to reaching local ranchers and residents in what should be shared goals.
[Moderating]
We just had a thread on this (it’s still on the front page, started by Velocity), but a lot has been posted to this one, too (started by Fotheringay-Phipps), so I’ll just merge them.
I can’t believe that so much wrong information has been posted in this thread.
Ask yourself- if we burnt the entire Amazon rain forest, how much oxygen would disappear from the atmosphere?
20%? No.
The answer is much less than 1%.
Most of the oxygen in our atmosphere is fossil oxygen. It was created long ago by photosynthetic organisms that are long dead and buried; the reduced carbon that this process created is buried deep underground, some as coal and oil, but most in the form of kerogen distributed in rocks. Even if you combusted the entire living biosphere of Earth the atmosphere would only lose a percent or two of oxygen partial pressure.
Sure, with a dead (burnt) biosphere, the oxygen constituent of the atmosphere would go down slowly, as the dead rocks of the atmosphere absorb it; but this would take hundreds of thousands of years.This is because the Earth’s crust and ocean is already pretty well oxygenated, so it can’t absorb much more without some sort of geological turnover.
This is supposed to be the Straight Dope, people - try to get it right!
I meant to say
…Sure, with a dead (burnt) biosphere, the oxygen constituent of the atmosphere would go down slowly, as the dead rocks of the crust absorb it…
This is a tricky subject, and even now the exact figures are somewhat vague, but the oxygen level in our atmosphere was set long ago, and is much, much larger than the mass of the biosphere. Lots of oxygen has been created in the past, and lots of this oxygen is incorporated into sedimentary rocks; but a lot of carbon has also been incorporated into the crust too. Some of this carbon is released by volcanoes, but the current oxygen level is more-or-less independent of current-day oxygen production.
Great quote, pity it’s false.
The african rainforest is twice as large, and the oceans contribute 5-7 times more oxygen that the amazon rainforest.
The real concern is irretrievable loss of biodiversity. There are, literally, thousands of species in the Amazonian forests that occur NO_WHERE else in the world, not even in sanctuaries/zoos. A great many not even described yet, never mind studied in detail. And once lost, they will of course be irreplaceable.
But our lives and future humans lives will go on. The flaw here is that Brazil is being paid what, a few tens of millions, not to use that land? It seems completely reasonable for them to convert their land into more economically useful things. Most of the value of these species is to tourists and scientists - and that may not justify such a colossal amount of land.
Apparently the rainforest is quite fragile and destroying more than 20 percent of it is as bad as destroying it all.
So might as well destroy it all…
Most of the value of those species is to those species.