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sidd

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2100 on: December 04, 2020, 01:43:52 AM »
Amazon deforestation is on the order of thousands of square miles (a thousand square mile is a quarter million hectares) The graf  by El Cid in reply # 2088 shows a drop of around 100 million hectares in total area under cultivation. So, cultivated area from amazon deforestation is tiny compared to reduction in total cultivated area.

sidd

oren

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2101 on: December 04, 2020, 05:00:13 AM »
Quote
the grain chart was increasing at a linear rate; population increases exponentially.
At this time population grows linearly at 80 million per year, thanks to slowly declining birth rates. Growth is expected to further slow to a bit less than linear in the coming decade.
OTOH, what is not shown in the grain chart is the amount of cumulative environmental degradation it took to produce that grain. Topsoil erosion, aquifer depletion, biodiversity decline, prime forest loss, accrual of chemicals, and many other accumulative long term processes.
I am reminded of Saudi Arabia and its success at becoming one of the world's top exporters of wheat. In 1992 it all looked really good. Eventually though, the aquifer ran out (and so did money to subsidize desalination for irrigation).
Humanity is an expert on robbing the bank, but the proceeds are not eternal.


wili

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2102 on: December 04, 2020, 06:22:33 AM »
The global population growth rate is still around 1%, which taken at face value would seem to indicate continued exponential growth (doubling in 72 years).

Except that this rate itself is falling as is expected to continue to fall at an increasing rate (as the global baby boom continues to age and die, and as women globally become more and more empowered). So yeah, over the long term it could probably be seen as roughly linear and eventually flat/declining. But we won't reach zero population growth, according to the charts at your link, till the end of the century. Of course, many other factors may come into play before then.

It will be interesting to see what, if any, effect the global covid crisis does to these numbers. Obviously, there will be increased deaths from covid, and they do not seem to be generally offset by decreased deaths from people traveling less, etc.

There were some early predictions that all those couples suddenly staying home all the time together would get bored and occupy themselves with lots more sex/baby-making. But that doesn't seem to have been the case (or they had 'safe' sex?).

I expect that it may have a dampening effect on the optimism people kinda have to have about the future to decide to bring a human into this world, but who knows...

ETA: I hadn't looked at these numbers closely for a couple years, but recent trends do look like they are arching in a less-than-linear direction. Yearly changes for the last few years (positive, in millions, years ending in June of stated year):

2015: 84.6
2016: 84.2  (down .4 from previous)
2017: 83.8  (down .4)
2018: 83.2  (down .6)
2019: 82.4  (down .8)
2020: 81.3  (down .9)

These numbers of course could bounce around in either direction in any given year, but the last six years paint a picture of not only falling annual growth numbers, but falling at an accelerating rate!

https://www.worldometers.info/world-population/

But I recall becoming rather excited a few years ago when, as you can see by the linked chart, the annual absolute increase fell below 80 million in 2005, from over 90 million in 1990, only to go up again to 84.6 by 2015. So...we'll see...

(Stupid question...what's the mathematical term for the point on a bell curve where it stops curving upward and starts curving down toward the peak? I was going to call it the asymptote, but that doesn't seem to be its meaning. Long time since I did formal study of math... :/ )
« Last Edit: December 04, 2020, 07:09:38 AM by wili »
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2103 on: December 04, 2020, 07:26:45 AM »
(Stupid question...what's the mathematical term for the point on a bell curve where it stops curving upward and starts curving down toward the peak? I was going to call it the asymptote, but that doesn't seem to be its meaning. Long time since I did formal study of math... :/ )
Inflection point is the term. It is the point where the curvature changes sign.

sidd

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2104 on: December 04, 2020, 07:28:34 AM »
4 inflections on a gaussian bell.

sidd

Shared Humanity

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2105 on: December 04, 2020, 03:06:48 PM »
Glad to see persons linking to research which helps us get a sense of the magnitude of the problem facing us with regards to sustainable food production. There is a wealth of material out there to draw on. The simple fact is that the green revolution, the massive increase in food production over the past 50 years was accomplished using practices that are simply not sustainable. This has allowed the population to grow well beyond a sustainable level. There are endless examples in nature of what happens when any species outgrows the food available in its environment. The result is always the same.

Nature has its ways to restore balance. They may seem cruel and harsh but they are unavoidable if we do not consciously work to restore that balance ourselves.
« Last Edit: December 04, 2020, 03:12:26 PM by Shared Humanity »

wili

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2106 on: December 05, 2020, 03:21:37 PM »
SH, I agree. But of course the cornucopians point out that we're not just any species, and we clever apes will come up with some other solution (or stop gap) to further extend our run.

This is about the time some technocornies start talking about colonizing space, to which I can only face palm.
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

dnem

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2107 on: December 05, 2020, 05:24:23 PM »

El Cid

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Général de GuerreLasse

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2109 on: December 06, 2020, 06:45:22 PM »
technocornies
:)

vs neomalthusian

Look at the image below the caption: "We work in over 80 countries"

What science did not do yesterday, nor today, it will not do tomorrow.

https://www.wfp.org
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Un petit croquis en dit plus qu'un grand discours, mais beaucoup moins qu'un gros chèque.
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vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2110 on: December 07, 2020, 03:46:51 PM »
Giant Vertical Farm Opens In Denmark
https://techxplore.com/news/2020-12-giant-vertical-farm-denmark.html



Fourteen layers of racks soar from floor to ceiling in this massive, 7,000-square-metre (75,350-square-foot) hangar used by Danish start-up Nordic Harvest.

https://www.nordicharvest.com/

The produce grown here will be harvested 15 times a year, despite never seeing soil or daylight. It is lit up around the clock by 20,000 specialised LED lightbulbs.

In this futuristic farm, little robots deliver trays of seeds from aisle to aisle.



Some 200 tonnes of produce are due to be harvested in the first quarter of 2021, and almost 1,000 tonnes annually when the farm is running at full capacity by the end of 2021, explains Anders Riemann, founder and chief executive of Nordic Harvest.

The farm uses one litre of water per kilogramme of produce, or 40 times less than underground farms and 250 times less than in fields, he says.

That would make the Taastrup warehouse one of Europe's biggest vertical farms.

In Denmark, a world leader in wind farms, about 40 percent of electricity consumption is wind-based. ... "In our case, we use 100 percent energy from windmills which makes us CO2-neutral," Anders Riemann, founder and chief executive of Nordic Harvest explained.

----------------------------------------------------
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2111 on: December 07, 2020, 04:13:57 PM »
Quote
With 20 football pitches, Denmark will be self-sufficient in salads and herbs

Quote
The roots turn into bio-fertilizer
Nothing is wasted. After the harvest, we use the roots to make fertilizer. We ferment the roots and add only natural minerals. We call it bio-fertilizer and it works better and is far less resource intensive than artificial fertilizer.

https://www.nordicharvest.com/saadangoervi/produktionen

One thing i am interested in the micronutrients in the food. Must be less then when grown from some good soil?
Þetta minnismerki er til vitnis um að við vitum hvað er að gerast og hvað þarf að gera. Aðeins þú veist hvort við gerðum eitthvað.

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2112 on: December 07, 2020, 04:20:28 PM »

One thing i am interested in the micronutrients in the food. Must be less then when grown from some good soil?

I would never want to eat food made in these factories. Pretty sure things grown there have no taste. The things I grow (in very rich soil) are full of taste. Humans by taste can tell lifeless, nutrient-poor food from good food. One of the main reasons for growing my own food is that I want to eat good tasting fruits and veggies and if you buy your food in supermarkets you can not. These artifical light/zerosoil plants must be even worse than supermarket food.
You must taste a fully ripe (grown in rich, natural soil) tomato, peach, apricot, melon or even apple, straight from the tree to know the difference. Fruits/veggies sold nowadays are usually just plain terrible - no wonder children don't want them.
« Last Edit: December 07, 2020, 04:27:16 PM by El Cid »

vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2113 on: December 07, 2020, 05:21:54 PM »
Quote
One thing i am interested in the micronutrients in the food. Must be less then when grown from some good soil?

Micronutrients are part of the basics of hydroponics. They are better accounted for than regular (depleted) soil.

The reason supermarket produce is tasteless is it's harvested unripe a week before it shows up on the shelf. The rationale of urban farms is the elimination of time wasted with transportation and storage.

The limitation of hydroponics is the absence of endobacteria and mycorrhizal fungi that may share beneficial peptides with their host. Its like the human microbiome. It's a necessary part of the plant.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

Bruce Steele

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2114 on: December 07, 2020, 06:20:46 PM »
might i mourn the plants never seeing the sun or feeling the warm breeze of a new spring day. The rabbits who would so enjoy the sweet green, the bugs that might otherwise bother us but feed a sky of birds. The fungi never grown, the soil as dead as a concrete slab. The air sanitized so the powered mildew never forms. All things controlled by panels and sensors but never feeling the soft touch of the gardener hands like all things are an end point to be rationalized, no circle of life. No circle of life and we wonder why the planet is dying ?  We are fucked up in the head.

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2115 on: December 07, 2020, 08:51:49 PM »
might i mourn the plants never seeing the sun or feeling the warm breeze of a new spring day. The rabbits who would so enjoy the sweet green, the bugs that might otherwise bother us but feed a sky of birds. The fungi never grown, the soil as dead as a concrete slab. The air sanitized so the powered mildew never forms. All things controlled by panels and sensors but never feeling the soft touch of the gardener hands like all things are an end point to be rationalized, no circle of life. No circle of life and we wonder why the planet is dying ?  We are fucked up in the head.

big thumbs up

gerontocrat

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2116 on: December 07, 2020, 09:55:04 PM »
I came across this in a Zane Grey novel written about a century ago. It's a sort of warning.

The Desert

Well, well, there’s no understandin’ the work of the desert. The way it develops the livin’ creatures! They all have to live, an’ livin’ on the desert is a thousand times harder than anywhere else. They all have to be perfect machines for destruction. Each seems so swift that he gets away, yet each is also so fierce an’ sure that he catches his prey. They live on one another, but the species doesn’t die out. That’s what stumps me about the desert. Take the human creatures. They grow fiercer than animals. Maybe that’s because nature did not intend man to live on the desert. An’ it is no place for man. Nature intended these classes of plants an’ these species of birds an’ beasts to live, fight, thrive, an’ reproduce their kind on the desert. But men can’t thrive nor reproduce their kind here.”

“How about the Indians who lived in the desert for hundreds of years?” asked Adam.
“What’s a handful of Indians? An’ what’s a few years out of the millions of years that the desert’s been here, just as it is now? Nothin’—nothin’ at all! Wansfell, there will be men come into the desert, down there below the Salton Sink, an’ in other places where the soil is productive, an’ they’ll build dams an’ storage places for water. Maybe a lot of fools will even turn the Colorado River over the desert. They’ll make it green an’ rich an’, like the Bible says, blossom as a rose. An’ these men will build ditches for water, an’ reservoirs an’ towns an’ cities, an’ cross the desert with railroads. An’ they’ll grow rich an’ proud. They’ll think they’ve conquered it. But, poor fools! they don’t know the desert! Only a man who has lived with the desert much of his life can ever know. Time will pass an’ men will grow old, an’ their sons an’ grandsons after them. A hundred an’ a thousand years might pass with fruitfulness still in the control of man. But all that is only a few grains of time in all the endless sands of eternity. The desert’s work will have been retarded for a little while.

But the desert works ceaselessly an’ with infinite patience. The sun burns, the frost cracks, the avalanche rolls, the rain weathers. Slowly the earth crust heaves up into mountains an’ slowly the mountains wear down, atom by atom, to be the sands of the desert. An’ the winds—how they blow for ever an’ ever! What can avail against the desert winds? They blow the sand an’ sift an’ seep an’ bury.... Men will die an’ the places that knew them will know them no more. An’ the desert will come back to its own. That is well, for it is what God intended.”
"Para a Causa do Povo a Luta Continua!"
"And that's all I'm going to say about that". Forrest Gump
"Damn, I wanted to see what happened next" (Epitaph)

vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2117 on: December 07, 2020, 10:15:17 PM »
Ecclesiastes 1:4 — "Men go and come, but earth abides.

https://en.m.wikipedia.org/wiki/Earth_Abides
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

wili

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2118 on: December 07, 2020, 11:02:15 PM »
"A force de chercher de bonnes raisons, on en trouve; on les dit; et après on y tient, non pas tant parce qu'elles sont bonnes que pour ne pas se démentir." Choderlos de Laclos "You struggle to come up with some valid reasons, then cling to them, not because they're good, but just to not back down."

Paddy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2119 on: December 08, 2020, 10:23:22 AM »
The FAO food price index has continued on the rising trend seen since May this year, reaching its highest point since December 2014: http://www.fao.org/worldfoodsituation/foodpricesindex/en/?_=1359546441963

Still significantly lower than it was back in its 2011 peak, however.

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2120 on: December 08, 2020, 02:10:05 PM »
The FAO food price index has continued on the rising trend seen since May this year, reaching its highest point since December 2014: http://www.fao.org/worldfoodsituation/foodpricesindex/en/?_=1359546441963

Still significantly lower than it was back in its 2011 peak, however.

A few observations:

- food prices have not gone anywhere in real terms in 50 years
- the 2011 food price rise was a direct cause of the Arabic Spring: in poor countries where a significant portion of the population's income is spent on foods, food price rises can lead to revolutions (just like 1789 France)
- oil and food prices are highly correlated for obvious reasons

Paddy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2121 on: December 08, 2020, 02:38:57 PM »
The FAO food price index has continued on the rising trend seen since May this year, reaching its highest point since December 2014: http://www.fao.org/worldfoodsituation/foodpricesindex/en/?_=1359546441963

Still significantly lower than it was back in its 2011 peak, however.

A few observations:

- food prices have not gone anywhere in real terms in 50 years
- the 2011 food price rise was a direct cause of the Arabic Spring: in poor countries where a significant portion of the population's income is spent on foods, food price rises can lead to revolutions (just like 1789 France)
- oil and food prices are highly correlated for obvious reasons

All true.  Although "not gone anywhere" only applies in that there's been no long term upwards or downwards trend in real terms; there have been significant fluctuations along the way, such as in 2011, when food prices were 20% higher than the norm by this measure.

Alexander555

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2122 on: December 09, 2020, 05:54:00 PM »
If you look at that soil in the amazon. Would they ever be able to produce food in a durable way ? Or would the sun kill everything in that top layer ?

Any soil in the right hands can become fertile, but it takes a lot of time and skill for that soil to become resilient and productive. The ancient Amazonian Indians created the famous terra preta. The logic that prevails right now in the Amazon will not lead to any good. Now what I find most worrying about this region is the work of Camilo Mora.

In fact, between the IPCC report, the work of Camilo Mora, the work of Dennis Meadows and that of James Lovelock, I have little illusion about our chances of adapting.

http://www.soc.hawaii.edu/mora/Publications/Mora%20059.pdf

https://www.ipcc.ch/site/assets/uploads/sites/4/2020/06/SRCCL_SPM_fr.pdf

Yesterday there was an article about deforestation in Zambia on Al Jazeera. They cut down 3000 square kilometers a year. So i went to take a look how big the country is. And to my surprise it's 750 000 square km. For a population of just 17 million people. And they have more rain than we have. And still many go hungry. So why many go hungry if you can turn any soil into a good soil. Is it just a lack of knowledge ?

Alexander555

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2123 on: December 09, 2020, 07:14:29 PM »
Giant Vertical Farm Opens In Denmark
https://techxplore.com/news/2020-12-giant-vertical-farm-denmark.html



Fourteen layers of racks soar from floor to ceiling in this massive, 7,000-square-metre (75,350-square-foot) hangar used by Danish start-up Nordic Harvest.

https://www.nordicharvest.com/

The produce grown here will be harvested 15 times a year, despite never seeing soil or daylight. It is lit up around the clock by 20,000 specialised LED lightbulbs.

In this futuristic farm, little robots deliver trays of seeds from aisle to aisle.



Some 200 tonnes of produce are due to be harvested in the first quarter of 2021, and almost 1,000 tonnes annually when the farm is running at full capacity by the end of 2021, explains Anders Riemann, founder and chief executive of Nordic Harvest.

The farm uses one litre of water per kilogramme of produce, or 40 times less than underground farms and 250 times less than in fields, he says.

That would make the Taastrup warehouse one of Europe's biggest vertical farms.

In Denmark, a world leader in wind farms, about 40 percent of electricity consumption is wind-based. ... "In our case, we use 100 percent energy from windmills which makes us CO2-neutral," Anders Riemann, founder and chief executive of Nordic Harvest explained.

----------------------------------------------------

This is what i call a complete disaster. 20000 LED lights to produce something as simple as food. To produce more food per square meter so that you can have more people per square meter. That all need more water than the little bit you save during the direct production. Joepy, now it can stop raining.

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2124 on: December 09, 2020, 08:51:43 PM »
Yesterday there was an article about deforestation in Zambia on Al Jazeera. They cut down 3000 square kilometers a year. So i went to take a look how big the country is. And to my surprise it's 750 000 square km. For a population of just 17 million people. And they have more rain than we have. And still many go hungry. So why many go hungry if you can turn any soil into a good soil. Is it just a lack of knowledge ?

It is a lack of knowledge, corrupt government, stupid laws, etc.

Case in point is Zimbabwe, once called the breadbasket of Africa. 390 000 km2. Has 14 million population. Could easily sustain 50 million. Easily!

After a so called landreform, they drove away white farmers, dividied up the land to smallholders and cronies of the maffialike government and the result is:

"Zimbabwe's commercial farming sector was traditionally a source of exports and foreign exchange, and provided 400,000 jobs. However, the government's land reform program badly damaged the sector, turning Zimbabwe into a net importer of food products.[2] For example, between 2000 and 2016, annual wheat production fell from 250,000 tons to 60,000 tons, maize was reduced from two million tons to 500,000 tons and cattle slaughtered for beef fell from 605,000 to 244,000.[102] Coffee production, once a prized export commodity, came to a virtual halt after seizure or expropriation of white-owned coffee farms in 2000 and has never recovered"

Just like the kolhoz system in Russia. Russia was a food importer in the 70s-80s!!! With the world's best soils and huge agricultural areas.

There was a saying in Hungary during my youth: start socialism in the Sahara and soon you will need to import sand. So true.

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2125 on: December 09, 2020, 09:01:40 PM »
Oh, and before you think that maybe Zimbabwe is not very good for agriculture, let me show you its climate (ie. the climate of Harare, its capital). This is the most perfect climate for man (no wonder, we all come from the highlands of Africa). No frosts, rarely above 30 degrees, 10-15 C in the morning, 20-25 in the afternoon. A rainy season of 5-6 months. Even without irrigation you should have at least one great harvest. If you have irrigation you can harvest at least twice per year, or even thrice.

Général de GuerreLasse

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2126 on: December 11, 2020, 05:53:29 PM »
Oh, and before you think that maybe Zimbabwe is not very good for agriculture, let me show you its climate (ie. the climate of Harare, its capital). This is the most perfect climate for man (no wonder, we all come from the highlands of Africa). No frosts, rarely above 30 degrees, 10-15 C in the morning, 20-25 in the afternoon. A rainy season of 5-6 months. Even without irrigation you should have at least one great harvest. If you have irrigation you can harvest at least twice per year, or even thrice.

My dear El Cid, take the leaders of Zimbabwe and send them to Switzerland and vice versa. In 5 years the Swiss will starve and the Zimbabweans will be happy and full.
La cravate est un accessoire permettant d'indiquer la direction du cerveau de l'homme.
Un petit croquis en dit plus qu'un grand discours, mais beaucoup moins qu'un gros chèque.
Pierre DAC

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2127 on: December 11, 2020, 09:47:34 PM »
Oh, and before you think that maybe Zimbabwe is not very good for agriculture, let me show you its climate (ie. the climate of Harare, its capital). This is the most perfect climate for man (no wonder, we all come from the highlands of Africa). No frosts, rarely above 30 degrees, 10-15 C in the morning, 20-25 in the afternoon. A rainy season of 5-6 months. Even without irrigation you should have at least one great harvest. If you have irrigation you can harvest at least twice per year, or even thrice.

My dear El Cid, take the leaders of Zimbabwe and send them to Switzerland and vice versa. In 5 years the Swiss will starve and the Zimbabweans will be happy and full.

most likely

Général de GuerreLasse

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2128 on: December 12, 2020, 11:25:57 AM »
Giant Vertical Farm Opens In Denmark
https://techxplore.com/news/2020-12-giant-vertical-farm-denmark.html



Fourteen layers of racks soar from floor to ceiling in this massive, 7,000-square-metre (75,350-square-foot) hangar used by Danish start-up Nordic Harvest.

https://www.nordicharvest.com/

The produce grown here will be harvested 15 times a year, despite never seeing soil or daylight. It is lit up around the clock by 20,000 specialised LED lightbulbs.

In this futuristic farm, little robots deliver trays of seeds from aisle to aisle.



Some 200 tonnes of produce are due to be harvested in the first quarter of 2021, and almost 1,000 tonnes annually when the farm is running at full capacity by the end of 2021, explains Anders Riemann, founder and chief executive of Nordic Harvest.

The farm uses one litre of water per kilogramme of produce, or 40 times less than underground farms and 250 times less than in fields, he says.

That would make the Taastrup warehouse one of Europe's biggest vertical farms.

In Denmark, a world leader in wind farms, about 40 percent of electricity consumption is wind-based. ... "In our case, we use 100 percent energy from windmills which makes us CO2-neutral," Anders Riemann, founder and chief executive of Nordic Harvest explained.

----------------------------------------------------

This is what i call a complete disaster. 20000 LED lights to produce something as simple as food. To produce more food per square meter so that you can have more people per square meter. That all need more water than the little bit you save during the direct production. Joepy, now it can stop raining.

Not to mention all the oil that had to be used to build it all. We need plastic, metals etc ... I would be curious to know the carbon footprint of a salad that grew in this Cornucopian delirium. Whenever human beings believe they have found a technological solution, they only increase the number of problems. As we say in France : "Science sans conscience n'est que ruine de l'âme" (Rabelais)
« Last Edit: December 13, 2020, 11:06:15 PM by Général de GuerreLasse »
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vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2129 on: December 15, 2020, 10:50:57 PM »
Error Correction Means California’s Future Wetter Winters May Never Come
https://www.pnnl.gov/news-media/error-correction-means-californias-future-wetter-winters-may-never-come

California and other areas of the U.S. Southwest may see less future winter precipitation than previously projected by climate models. After probing a persistent error in widely used models, researchers at the Department of Energy's Pacific Northwest National Laboratory estimate that California will likely experience drier winters in the future than projected by some climate models, meaning residents may see less spring runoff, higher spring temperatures, and an increased risk of wildfire in coming years.

... When new climate model generations are refined and grow increasingly accurate, some biases are reduced while others linger. One such long-lived bias in many models is the misrepresentation of an important circulation feature called the intertropical convergence zone, commonly known as the ITCZ.
Many climate models mistakenly depict a double ITCZ: two bands appearing in both hemispheres instead of one, which imbues uncertainty in model projections. Scientists refer to this as the double-ITCZ bias. Variations in the wind and pressure systems that influence the ITCZ add to that uncertainty.

To peer through the effect of the double-ITCZ bias and create more accurate projections, Dong and atmospheric scientist Ruby Leung analyzed data from nearly 40 climate models, uncovering statistical and mechanistic links between the bias and the models' outputs. The lion's share of the models they analyzed projected a sharpening of California's seasonal precipitation cycle, bringing wetter winters and drier fall and spring seasons.

Winter precipitation includes more than just rain, encompassing snowpack in mountainous areas and other factors that influence climate processes throughout the year.

Those uncovered relationships, Dong said, now cast doubt on estimations from CMIP5 models that projected wetter winters in the future. Models saddled with a larger double-ITCZ bias, it turns out, tend to exaggerate the U.S. Southwest's wetter winters. They also understate the drier winters in the Mediterranean Basin, which also features pronounced wet winters and dry summers similar to California, under warming climate scenarios.

The double-ITCZ bias is prominent in all CMIP5 climate models, said Leung, as well as CMIP6 models, the most recent generation, though the latter were not considered in this work. "If you look at the whole ensemble of models," said Leung, "you see quite similar biases."

Correcting for the bias reduces winter precipitation projections to a level that's roughly equal to California's current winters, amounting to little change and no future wetter winters. In the Mediterranean Basin, said Dong, the correction means winter drying will be intensified by 32 percent.

"An important implication of this work," said Dong, "is that a reduction in estimated winter precipitation will likely mean a reduction in spring runoff and an increase in spring temperature, and both increase the likelihood of wildfire risk in California."

The findings do not bode well for agricultural production, as over one third of the country's vegetables are grown in California soil, and two thirds of its fruits and nuts are grown on California farms, according to the California Department of Food and Agriculture. Almonds and grapes, two especially water-hungry crops, were among the state's top producing commodities, bringing in a combined $11.5 billion in 2019.
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2130 on: December 15, 2020, 11:44:47 PM »
Quote
Abstract
The double-Intertropical Convergence Zone (ITCZ) problem, in which excessive precipitation is produced in the Southern Hemisphere tropics, which resembles a Southern Hemisphere counterpart to the strong Northern Hemisphere ITCZ, is perhaps the most significant and most persistent bias of global climate models. In this study, we look to the extratropics for possible causes of the double-ITCZ problem by performing a global energetic analysis with historical simulations from a suite of global climate models and comparing with satellite observations of the Earth’s energy budget. Our results show that models with more energy flux into the Southern Hemisphere atmosphere (at the top of the atmosphere and at the surface) tend to have a stronger double-ITCZ bias, consistent with recent theoretical studies that suggest that the ITCZ is drawn toward heating even outside the tropics. In particular, we find that cloud biases over the Southern Ocean explain most of the model-to-model differences in the amount of excessive precipitation in Southern Hemisphere tropics, and are suggested to be responsible for this aspect of the double-ITCZ problem in most global climate models.

https://www.pnas.org/content/110/13/4935

Interesting piece vox.

The above is from 2013 so this problem has been with us for a while. 
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sidd

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2131 on: December 16, 2020, 07:42:24 AM »
Yes, the double ITCZ has been a difficulty for a long time. I wonder if that is due to the ocean mixing overestimate

http://www.realclimate.org/index.php/archives/2020/12/unforced-variations-dec-2020/#comment-781873

--
"Hansen addresses this on pg 34-35 of

http://www.columbia.edu/~jeh1/mailings/2019/20191211_Fire.pdf

“I suspected that all ocean models, ours included, suffered from what I described as excessive ‘sludge.’ By this, I meant excessive small-scale mixing of ocean properties.”

“My suspicion was that the turbulence parameterization caused excessive mixing. Such mixing makes global ocean models more ‘well behaved.’ The real world, however, is not so well-behaved. ”

--

This discussion is probably better held in a different thread.

sidd

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2132 on: December 16, 2020, 08:29:17 AM »
As climate models can not even "backcast" localized Holocene Optimum conditions (especially precipitation, eg Europe, Green Sahara, Fertile Crescent etc.), I have not a bit of confidence in them saying anything about future California winters.
In my opinion it is much more useful to study Eeemian and Holocene optimum conditions to judge what is likely to come

dnem

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2133 on: December 16, 2020, 01:41:07 PM »
Long article in today's New York Times about how Siberia is becoming suitable for agriculture as the climate shifts due to AGW:

https://www.nytimes.com/interactive/2020/12/16/magazine/russia-climate-migration-crisis.html



Across Eastern Russia, wild forests, swamps and grasslands are slowly being transformed into orderly grids of soybeans, corn and wheat. It’s a process that is likely to accelerate: Russia hopes to seize on the warming temperatures and longer growing seasons brought by climate change to refashion itself as one of the planet’s largest producers of food.

But for a few nations, climate change will present an unparalleled opportunity, as the planet’s coldest regions become more temperate. There is plenty of reason to think that those places will also receive an extraordinary influx of people displaced from the hottest parts of the world as the climate warms. Human migration, historically, has been driven by the pursuit of prosperity even more so than it has by environmental strife. With climate change, prosperity and habitability — haven and economic opportunity — will soon become one and the same.

And no country may be better positioned to capitalize on climate change than Russia. Russia has the largest land mass by far of any northern nation. It is positioned farther north than all of its South Asian neighbors, which collectively are home to the largest global population fending off displacement from rising seas, drought and an overheating climate.


El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2134 on: December 16, 2020, 04:57:56 PM »
Long article in today's New York Times about how Siberia is becoming suitable for agriculture as the climate shifts due to AGW:.....
And no country may be better positioned to capitalize on climate change than Russia.

I have written about this previously but found scepticism. AGW is always terrible, and it can not be good for anyone - that is the general line of thinking here...

one more thoguht about Russia and Ukraine:.

There is another factor here (besides a warming climate): both in Russia and Ukraine the transition from the kolhoz system to modern methods is not so fast and still ongoing and helps increase production gradually (see attached chart)

another thought: Canada is also going to be a big winner of AGW, maybe bigger than Russia.
(and don't forget Poland, Belorussia and even Kazakhstan!)

Bruce Steele

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2135 on: December 16, 2020, 05:05:03 PM »
El CID,      El Niño , La Niña , and the PDO warm and cold events all have predictive value of precipitation for different regions. But I don’t see any models that accurately predict any of them two or three years in advance , let alone decades in advance, so any model predictions of long term precipitation will be flawed by where we are in any one of the cycles mentioned above. Cold or warm water PDO events can last multiple decades so model predictions of precipitation will only be accurate in very long term averages and since we farm on annual availability of rains I would much prefer better predictive values to the Ninos and PDO. Our average precipitation over century scales is interesting but not very useful considering the very likely heating involved on century scale timelines.
« Last Edit: December 16, 2020, 05:13:52 PM by Bruce Steele »

El Cid

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2136 on: December 16, 2020, 08:11:52 PM »
El CID,      El Niño , La Niña , and the PDO warm and cold events all have predictive value of precipitation for different regions. But I don’t see any models that accurately predict any of them two or three years in advance , let alone decades in advance, so any model predictions of long term precipitation will be flawed by where we are in any one of the cycles mentioned above. Cold or warm water PDO events can last multiple decades so model predictions of precipitation will only be accurate in very long term averages and since we farm on annual availability of rains I would much prefer better predictive values to the Ninos and PDO. Our average precipitation over century scales is interesting but not very useful considering the very likely heating involved on century scale timelines.

As a farmer you are most certainly right. What I pointed out is that models don't even get right average precipitation rates (which we know quite well from a number of sources) even 5-10 thousand years ago, so we can not expect them to have the ability to forecast future precipitation patterns.
The variablity of precipitation is of course another huge unknown and as you say is possibly more important for agriculture especially in climates with unstable and/or very seasonal rain patterns.

Général de GuerreLasse

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2137 on: December 20, 2020, 08:04:00 PM »
El CID,      El Niño , La Niña , and the PDO warm and cold events all have predictive value of precipitation for different regions. But I don’t see any models that accurately predict any of them two or three years in advance , let alone decades in advance, so any model predictions of long term precipitation will be flawed by where we are in any one of the cycles mentioned above. Cold or warm water PDO events can last multiple decades so model predictions of precipitation will only be accurate in very long term averages and since we farm on annual availability of rains I would much prefer better predictive values to the Ninos and PDO. Our average precipitation over century scales is interesting but not very useful considering the very likely heating involved on century scale timelines.

As a farmer you are most certainly right. What I pointed out is that models don't even get right average precipitation rates (which we know quite well from a number of sources) even 5-10 thousand years ago, so we can not expect them to have the ability to forecast future precipitation patterns.
The variablity of precipitation is of course another huge unknown and as you say is possibly more important for agriculture especially in climates with unstable and/or very seasonal rain patterns.

"Forecasting is difficult especially when it concerns the future."
Pierre DAC
 ;D    :-X
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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2138 on: December 21, 2020, 08:38:13 AM »
"Forecasting is difficult especially when it concerns the future."
Pierre DAC
 ;D    :-X

Not only that! Models can not even recreate known (regional) past climates, especially precipitation. So why would we think they can forecast the future???

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2139 on: December 21, 2020, 08:02:06 PM »
Read and despair?

https://www.nature.com/articles/s41893-020-00656-5.epdf
Proactive conservation to prevent habitat losses to agricultural expansionDavid R. Williams1,2,9 ✉, Michael Clark3,9 ✉, Graeme M. Buchanan4, G. Francesco Ficetola5,6, Carlo Rondinini7 and David Tilman 2,8

Quote
The projected loss of millions of square kilometres of natural ecosystems to meet future demand for food, animal feed, fibre and bioenergy crops is likely to massively escalate threats to biodiversity. Reducing these threats requires a detailed knowledge of how and where they are likely to be most severe. We developed a geographically explicit model of future agricultural land clearance based on observed historical changes, and combined the outputs with species-specific habitat preferences for 19,859 species of terrestrial vertebrates.

We project that 87.7% of these species will lose habitat to agricultural expansion by 2050, with 1,280 species projected to lose ≥25% of their habitat. Proactive policies targeting how, where, and what food is produced could reduce these threats, with a combination of approaches potentially preventing almost all these losses while contributing to healthier human diets. As international biodiversity targets are set to be updated in 2021, these results highlight the impor-tance of proactive efforts to safeguard biodiversity by reducing demand for agricultural land.
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Niall Dollard

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2140 on: December 28, 2020, 09:51:13 AM »
Russian trawler sinks near Novaya Zemlya.

2 saved and 17 missing. Reports say ice accretion was the cause of the sinking.

I wonder was the trawler fishing further north than usual because of lack of sea ice and got caught out ?

www.rt.com/russia/510885-fishing-boat-murmansk-sinks/amp/

vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2141 on: January 13, 2021, 08:52:31 PM »
Earth to Reach Temperature Tipping Point In Next 20 to 30 Years, New Study Finds
https://phys.org/news/2021-01-earth-temperature-years.html


Integrated global temperature response curves for normalized photosynthesis (green dashed line), respiration (red dashed dotted line), and a mass balance estimate of the land sink (blue solid line) in relation to current climate (gray bar), where the mean across each curve sums to zero. Photosynthesis represents the integration of C3 and C4 curves (Fig. 1) weighted by global fraction of C3/C4 photosynthesis (37). The gray shaded bar represents observed mean annual temperature range from 1991 to 2015 (9, 22), and vertical dashed line indicates current annual mean temperature at FLUXNET tower sites.

Earth's ability to absorb nearly a third of human-caused carbon emissions through plants could be halved within the next two decades at the current rate of warming, according to a new study in Science Advances.

Using more than two decades of data from measurement towers in every major biome across the globe, the team identified a critical temperature tipping point beyond which plants' ability to capture and store atmospheric carbon—a cumulative effect referred to as the "land carbon sink"—decreases as temperatures continue to rise.

Over the past few decades, the biosphere has generally taken in more carbon than it has released, mitigating climate change.

But as record-breaking temperatures continue to spread across the globe, this may not continue; the NAU, Woodwell Climate and Waikato researchers have detected a temperature threshold beyond which plant carbon uptake slows and carbon release accelerates.

Lead author Katharyn Duffy, a postdoctoral researcher at NAU, noticed sharp declines in photosynthesis above this temperature threshold in nearly every biome across the globe, even after removing other effects such as water and sunlight.

"We know that the temperature optima for humans lie around 37 degrees Celsius (98 degrees Fahrenheit), but we in the scientific community didn't know what those optima were for the terrestrial biosphere," Duffy said.

The results were alarming.

The researchers found that temperature "peaks" for carbon uptake—18 degrees C for the more widespread C3 plants and 28 degrees C for C4 plants—are already being exceeded in nature, but saw no temperature check on respiration. This means that in many biomes, continued warming will cause photosynthesis to decline while respiration rates rise exponentially, tipping the balance of ecosystems from carbon sink to carbon source and accelerating climate change.

"Different types of plants vary in the details of their temperature responses, but all show declines in photosynthesis when it gets too warm," said NAU co-author George Koch.

Right now, less than 10 percent of the terrestrial biosphere experiences temperatures beyond this photosynthetic maximum. But at the current rate of emissions, up to half the terrestrial biosphere could experience temperatures beyond that productivity threshold by mid-century—and some of the most carbon-rich biomes in the world, including tropical rainforests in the Amazon and Southeast Asia and the Taiga in Russia and Canada, will be among the first to hit that tipping point.


The normalized global temperature response of C3 photosynthesis (green), which exhibits TmaxP of 18°C, C4 photosynthesis (yellow) that exhibits TmaxP at 28°C, and total ecosystem respiration (brown) derived from the FLUXNET 2015 synthesis dataset. The minor thermal optima observed in C4 classified sites validate the mixed C3/C4 nature of some ecosystems and were well explained by the sum of two Gaussian curves (see Materials and Methods). All fluxes were normalized and fit over ambient temperatures observed by FLUXNET (up to 38°C), where the mean across each curve sums to zero. Shaded areas represent the 90% confidence interval of projections.

K.A. Duffy el al., "How close are we to the temperature tipping point of the terrestrial biosphere?," Science Advances (2021)
https://advances.sciencemag.org/content/7/3/eaay1052

---------------------------------------------

... sadly, there's an echo of LTG there ... we were warned
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2142 on: January 13, 2021, 09:58:43 PM »
And that is the sort of thing we want to avoid but we have very little time to stop this. Book keeping won´t cut it.

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vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2143 on: March 03, 2021, 03:39:06 PM »
Global Warming Poses Threat to Food Chains
https://phys.org/news/2021-03-global-poses-threat-food-chains.html

Rising temperatures could reduce the efficiency of food chains and threaten the survival of larger animals, new research shows.

Scientists measured the transfer of energy from single-celled algae (phytoplankton) to small animals that eat them (zooplankton).

The study—by the University of Exeter and Queen Mary University of London, and published in the journal Nature—found that 4°C of warming reduced energy transfer in the plankton food webs by up to 56%.

Warmer conditions increase the metabolic cost of growth, leading to less efficient energy flow through the food chain and ultimately to a reduction in overall biomass

"Phytoplankton and zooplankton are the foundation of food webs that support freshwater and marine ecosystems that humans depend on.

"Our study is the first direct evidence that the cost of growth increases in higher temperatures, limiting the transfer of energy up a food chain."

"In general, about 10% of energy produced on one level of a food web makes it up to the next level," said Dr. Diego Barneche, of the Australian Institute of Marine Science and the Oceans Institute at the University of Western Australia.

"This happens because organisms expend a lot of energy on a variety of functions over a lifetime, and only a small fraction of the energy they consume is retained in biomass that ends up being eaten by predators.

"Warmer temperatures can cause metabolic rates to accelerate faster than growth rates, which reduces the energy available to predators in the next level up the food web."

The study measured nitrogen transfer efficiency (a proxy for overall energy transfer) in freshwater plankton that had been exposed to a seven-year-long outdoor warming experiment in the UK.

"Warming impairs trophic transfer efficiency in a long-term field experiment" Nature (2021).
https://www.nature.com/articles/s41586-021-03352-2
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

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vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2144 on: March 05, 2021, 03:39:11 PM »
Collapse of Northern California Kelp Forests Will Be Hard to Reverse
https://phys.org/news/2021-03-collapse-northern-california-kelp-forests.html

A new study led by researchers at UC Santa Cruz documents this dramatic shift in the coastal ecosystem and analyzes the events that caused it. This was not a gradual decline, but an abrupt collapse of the kelp forest ecosystem in the aftermath of unusual ocean warming along the West Coast starting in 2014, part of a series of events that combined to decimate the kelp forests.

Published March 5 in Communications Biology, the study shows that the kelp forests north of San Francisco were resilient to extreme warming events in the past, surviving other strong marine heatwaves and El Niño events. But the loss of a key urchin predator, the sunflower sea star, due to sea star wasting disease left the kelp forests of Northern California without any predators of sea urchins, which are voracious grazers of kelp.

There were a lot of disruptions at one time that led to this collapse, and the system now persists in this altered state," said first author Meredith McPherson, a graduate student in ocean science at UC Santa Cruz. "It's a naturally dynamic system that has been really resilient to extreme events in the past, but the die-off of sunflower stars caused the resilience of the ecosystem to plummet. As a result, the kelp forests were not able to withstand the effects of the marine heatwave and El Niño event combined with an insurgence of sea urchins."

The researchers used satellite imagery from the U.S. Geological Survey's Landsat missions going back to 1985 to assess historical changes in kelp forest canopy cover.



Kelp forests declined all along the California coast, but not to the same extent as in Northern California. Bull kelp is an annual species that regrows each year, which may make it more sensitive to these stressors than giant kelp. But another critical difference in Northern California is the absence of other urchin predators such as sea otters, which have enabled patches of healthy kelp forest to persist in Monterey Bay, for example.

"Sea otters haven't been seen on the North Coast since the 1800s," McPherson said. "From what we observed in the satellite data from the last 35 years, the kelp had been doing well without sea otters as long as we still had sunflower stars. Once they were gone, there were no urchin predators left in the system."

Large-scale shift in the structure of a kelp forest ecosystem co-occurs with an epizootic and marine heatwave, Communications Biology, (2021)
https://www.nature.com/articles/s42003-021-01827-6
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

Insensible before the wave so soon released by callous fate. Affected most, they understand the least, and understanding, when it comes, invariably arrives too late

kassy

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2145 on: March 05, 2021, 03:59:18 PM »
In changing oceans, sea stars may be 'drowning'

...

"It's a cascade of problems that starts with changes in the environment," Hewson said, explaining that most of the organic matter comes from microscopic algae exudation (a discharge), zooplankton excretion and egestion, and from decaying animal carcasses. This stimulates a group of bacteria called copiotrophs, which survive on carbon and rapidly consume organic matter, he said.

The copiotrophs respire, he said, so while absorbing the organic matter, they deplete oxygen in the sea star's watery space.

"It's organic matter concentrations in the water," he said. "If you have a dead and rotting starfish next to starfish that are healthy, all of that dead one's organic matter drifts and fuels the bacteria, creating a hypoxic environment. It looks like disease is being transmitted."

...

https://phys.org/news/2021-01-oceans-sea-stars.html

paper:
https://www.frontiersin.org/articles/10.3389/fmicb.2020.610009/full

For those interested in the Sea Star part

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Bruce Steele

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2146 on: March 05, 2021, 05:21:32 PM »
Kassy, The sea star dieoff paper exposes acidification and hypoxia , already an annual springtime occurrence in the Calif. Current Ecosystem ,  exacerbating conditions on a more micro level at the skin / water surface layer for starfish. Organic matter that resulted from hot water killing phytoplankton  settles unto the skin of soft skinned sea stars where it builds up conditions ripe for bacterial remineralization. The remineralization further drops pH and oxygen resulting in skin lesions which are entry points for other pathogens. For starfish with harder smooth skin the organic matter doesn’t build up so not all starfish are susceptible to the conditions of low oxygen/ low pH at the skin surface. Not all starfish are affected.
 We also saw Red Sea urchins with lesions during the same time period , a condition called “ blackspot disease.”  It may be that some sea urchins are susceptible to the same problems as sea stars.
 There are purple urchin barrens now within prime Sea Otter habitate that Sea Otters have habituated for sixty years and there are currently urchin removal efforts by humans to try to control them. Purple urchins do not offer food value to sea otters when they build into high concentrations so you can get urchin barrens within Sea Otter territory.
 In Southern Calif. we have lobster and a fish called a Sheepshead that prey on Sea Urchins so there are a couple predators in Southern Calif. not found North of Point Conception . But even in Southern Calif. purple urchins have denuded the kelp at San Miguel Island, the northernmost of the Channel Islands. We have seen large purple urchin dieoffs during former El Niño events of 82-83 and 97-98 and when water temperatures exceed 75F we will see purples die in Southern Calif again but the problem for Northern Calif is we don’t get water temperatures that high so the purples will persist even through the next big El Niño.
 
 

vox_mundi

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2147 on: March 09, 2021, 01:04:21 AM »
Sea Otters Maintain Remnants of Healthy Kelp Forest Amid Sea Urchin Barrens
https://phys.org/news/2021-03-sea-otters-remnants-healthy-kelp.html

Sea otters have long been recognized as a classic example of a keystone species, a dominant predator that maintains the balance of kelp forest ecosystems by controlling populations of sea urchins, which are voracious kelp grazers.

Since 2014, however, California's kelp forests have declined dramatically, and vast areas of the coast where kelp once thrived are now "urchin barrens," the seafloor carpeted with purple sea urchins and little else. This has occurred even in Monterey Bay, which hosts a large population of sea otters.

In 2017, UC Santa Cruz graduate student Joshua Smith set out to understand why. "Here in Monterey Bay, we now have a patchy mosaic, with urchin barrens devoid of kelp directly adjacent to patches of kelp forest that seem pretty healthy," Smith said. "We wanted to know how did this sea urchin outbreak happen where there are so many otters, how did the otters respond, and what does that mean for the fate of kelp forests here on the Central Coast?"

Smith's findings, published March 8 in Proceedings of the National Academy of Sciences, tell a fascinating story of how the behavioral responses of predators and prey to changing conditions can determine the fate of an entire ecosystem.

... Smith and his colleagues found that sea otters on the Central Coast responded to the urchin outbreak by increasing their urchin consumption dramatically, eating about three times as many sea urchins as they had prior to 2014. Thanks to an abundance of prey (including an increase in mussels as well as urchins), the sea otter population increased substantially after 2014, from about 270 to about 432 sea otters in the Monterey region at the southern end of Monterey Bay.

Yet the urchin barrens remained. A close look at sea otter foraging behavior explained why. Smith's team found that the otters were feeding on urchins in the remaining patches of kelp forest, but not in the urchin barrens.

"It's easy to see from shore where they are diving repeatedly and coming up with sea urchins," he said.

The dive team surveyed those places, as well as areas not being targeted by otters, and collected urchins to examine in the lab. The researchers found that urchins from the kelp beds had much higher nutritional value than those from the urchin barrens, with large, energy-rich gonads. In the barrens, however, the urchins are starved and not worth the effort to a hungry otter.

By doing this, the sea otters are helping to maintain those patches of healthy kelp forest, which are now crucially important for the persistence of giant kelp along the coast. Spores produced from those remaining patches could eventually reseed the barren areas and restore the kelp beds. ...



Joshua G. Smith el al., "Behavioral responses across a mosaic of ecosystem states restructure a sea otter–urchin trophic cascade," PNAS (2021).
https://www.pnas.org/content/118/11/e2012493118
“There are three classes of people: those who see. Those who see when they are shown. Those who do not see.” ― Leonardo da Vinci

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Bruce Steele

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2148 on: March 09, 2021, 11:29:54 PM »
Voxmundi, Well I am hardly non biased on the sea otter/urchin story but hoping that sea otters will fix this problem is not a whole lot more likely than the pycnopodia making a miraculous return. I know some divers think the kelp will just miraculously return even without sea otters or starfish.
 Some of my more pragmatic friends are trying to kill the purple urchins and have ongoing removal efforts but the red urchins fill in after you take the purple ones so now we get into regulatory problems with destroying a resource. Red Sea urchins are a regulated fishery with size limits , seasons, limited permits and closed areas. So just going out to kill red urchins with hammers is a problem.
 I know and despise sea otter politics. I am well versed. Just type my name and sea otters into google search. Tom may find a reason to really not like me. I negotiated an exemption to the ESA on sea otter take almost thirty years ago. Fisheries fought clear to the Supreme Court trying to save it but we lost. But three hundred sea urchin divers fought off the US Fish and Wildlife for over twenty years so losing slowly is actually success when you are fighting the US government in a court of law. They made a negotiated deal and reneged so we gave em hell.

https://g2kr.com/urchin-removal-petition

Tom_Mazanec

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Re: Climate change, the ocean, agriculture, and FOOD
« Reply #2149 on: March 10, 2021, 03:01:57 AM »
Yeah, sea otters are my second favorite furry four-foots. There has to be measures taken to protect the southern sub-species, which are threatened with extinction. So I guess Bruce Steele does not like me now  ;D
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