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Oceans are in fact largely great blue deserts. Occupying less than one percent of the ocean floor, coral reefs are home to more than twenty-five percent of marine life. And 90% of all ocean life is found in coastal waters.

To me this means that we should invest a focused effort in planting coral reefs in protected areas (and protecting additional areas for the same.) This would have the effect of creating more marine sanctuaries safe from human fishing pressure, which will seed surrounding fishery areas and become a win-win. New Zealand has done this to great effect (creating protected areas, not planting reefs.)

I think however the typically human reaction is see a coral reef that's dying and try to use re-planting to bring it back to life. Unless that's coupled with re-planting higher-temperature corals, that's neither going to work or be sustainable as the Oceans continue to warm for hundreds of years to come. I would rather see more resistant corals being planted, or coral reefs being planted in colder waters.

Lastly, while it is a great tragedy that the coral reefs are dying, it should be noted that the Earth has been here before and come back from it at the end of the last ice age when sea levels rapidly rose 400 feet and drowned all of Earth's reefs at the time. That doesn't make things any less tragic, or absolve us of the blame, but perhaps helps frame things by remembering that Earth is not a steady-state system but a rather a system of constant flux and adaptation.

I hope that in the same way humans have been having massive negative effects on nature and the climate, we can also pool together and create some equally impressive positive effects on the natural world.




> it should be noted that the Earth has been here before and come back from it

There weren't 7 billion humans back then. My big concern is that we're well above the pre-green-revolution carrying capacity of Earth and it wouldn't take all that much to put us in a position where we can't feed 3 billion people. It's possible that a greenhouse earth will give us more arable land to work with, and we'll be just fine. It's likely that things will become ugly during the transition, as formerly arable land becomes desert, the oceans stop providing food, and mass migration causes global unrest. A lot of people are going to starve.


For those that want to dive deeper it looks like this meta-analysis might be a good starting point for the human carrying capacity of the earth.

https://academic.oup.com/bioscience/article/54/3/195/223056

> When taking all studies into account, the best point estimate is 7.7 billion people; the lower and upper bounds, given current technology, are 0.65 billion and 98 billion people, respectively.


> the lower and upper bounds, given current technology, are 0.65 billion and 98 billion people, respectively.

The answer is "anywhere from a tenth of the people currently alive to 13.5 times as many as are currently alive." Absolutely useless. A range covering more than two orders of magnitude. May as well say, "We don't know."


> Absolutely useless

Not at all. To say "we don't know" might mean that we don't know the order of magnitude. Order of magnitude estimates to the first or second decimal place are oftentimes more than enough to hone in on a solution. In this case the two orders of magnitude set a clear bound (assuming the capacity estimate are accurate) for the near future at the high end and provide a warning sign for the present.


This is a meta-analysis. They reference many different papers. Many of them come to different conclusions. If you want more certainty you can get it by starting to read the papers the reference and deciding which ones you think are reasonable.


Seems like this calculation completely disregards the emotional effects of that many people in such close proximity.


Well if we have 98 billion people on earth - lets see how dense we get. This [site](http://www.zo.utexas.edu/courses/thoc/land.html) argues there's about 24,642,757 square miles of habitable land on Earth - this is discounting deserts and mountains, and of course oceans.

That puts about 6 people per acre in all the habitable spots on the globe.

To put that into perspective, Manhattan has about [27,000](https://www1.nyc.gov/site/planning/data-maps/nyc-population/...) residents per square mile - or 42 people per acre. There are other, denser cities out there as well. People-dense parts like this make other parts more people-sparse.

I'm sure by the time (if) we have 98B people - Manhattan will be much more people-dense, and many more cities will be similarly dense. So it may be that 50B people live in massive, dense cities, leaving the other 50B to be in more suburban-yet-still-dense zones.

However, this is the 'idea' case of all habitable land being used for habitation. There is also the need for farms and industrial land, and all manner of other places for human activity, and the vast things needed to support it. Ideas like vertical farming solve for some of these, but are not perfect.


98B might be possible if we did everything perfectly efficiently and optimized every single part of the planet leaving absolutely nothing allocated for the bare essentials to keep people living. The reality is we would never get anywhere close to that level of efficiency and would destroy the planet much sooner.


At Dutch population density (1,312 people per square mile[1]) that would be 32 trillion people so even 100 billion people should leave plenty of space.

[1]http://www.worldometers.info/world-population/netherlands-po...


Would AR/VR help with this at all? I was thinking that with the earlier article about Japan's micro apartments, if having the walls covered with 3D screens (or even mirrors) would give a bigger sense of space and help with mental well being.


I can say from experience that VR absolutely helps dispel cabin fever. I once lived in a fairly small apartment in a dense city. Turning on a big box fan in my VR area and then going out to wide open spaces like the mountains in Skyrim VR made me feel better almost instantly.


Seems likely, if you decided to dive into the various papers they are pulling from I'd be really interested to hear about which ones consider sociological problems like emotional effects of over crowding!


And heading to 10 billion. On the back of unsustainable use of soil, water, fish, natural resources in general, antibiotics, antifungals, etc. That worries me too.


It's pretty easy to turn energy into food, in large quantities in small areas, even in incredibly hostile environments. (AKA greenhouses). We don't do so only because food and arable land is so incredibly cheap that it's not worth it.

Farming is only 0.07% of the US economy. A small increase in food prices would vastly increase supply. Africa would probably be screwed, but that would have nothing to do with our ability to feed them and be solely due to economics not making it profitable.


Is farming 0.07% of the US economy or of the US workforce? Those are totally different things. Its certainly not 0.07% of US arable land

There were bread and rice riots around the globe just 10 years ago.

https://en.wikipedia.org/wiki/2007%E2%80%9308_world_food_pri...


> Is farming 0.07% of the US economy or of the US workforce?

0.07% of GDP. It's a higher percentage of workforce, but still under 1% directly employed. Land area is irrelevant to my argument -- greenhouses can feed a lot of people in a small area.

> There were bread and rice riots around the globe just 10 years ago.

All that says is that Capitalism does a really bad job of supplying stuff to people without any money.


Well, the Earth doesn't care about humans, per se.

So the Earth will still come back from it. And even the human species will likely come back from it. But technological society? That's a lot more iffy.


But a lot of people starving will probably help the coral reefs recover since there will be fewer people using energy and polluting.


I don't think many people are seriously thinking that starving is the next problem. These days it seems like war comes before people start starving to death.

https://www.nytimes.com/2015/03/03/science/earth/study-links...


No-one studying coral reefs now thinks they have much chance of surviving beyond mid-century given already baked-in ocean heating.


while it is a great tragedy that the coral reefs are dying, it should be noted that the Earth has been here before and come back from it

Nobody's worried the reefs will never come back. They are worried they won't be back anytime soon and we'll have to make do for the next hundred thousand years.


You're off by about two orders of magnitude there, judging from recent history.

But even then, that's a long time from a human perspective, I think we could re-plant reefs the same way we replant forests on timescales of a couple generations or less.

Edit: obviously it would be better if we didn't have to do that, but that ship has sailed.


2 orders of magnitude in which direction?


To me this means that we should invest a focused effort in planting coral reefs in protected areas (and protecting additional areas for the same.)

I'm not a marine biologist, but from my understanding the big threat to coral reefs is ocean acidification. If this trend continues, we won't be able to do anything to save the reefs. There's no use in re-planting corals if the entire ocean is too acidic for them to survive in, coastal or otherwise.


It’s also temperature. Reefs bleach at a certain temperature. They can recover from this, but very slowly and not if they bleach again the next year and the year after that.

Apparently this is what happened the last two years. Also, apparently it’s never happened two years in a row before.

Source: Was at the Great Barrier Reef a month ago. The marine biologist on board was very informative.


>Earth is not a steady-state system but a rather a system of constant flux and adaptation.

I just want to point out that the main mechanism of adaptation is that the creatures less suited to survival die out.


> Earth has been here before

The Earth may be effectively eternal (from a human standpoint), but human species is not. More likely, humans will be around, but modern human society would likely suffer an extinction event at some point with our trajectory.

I like your idea of higher-temp corals. Are you aware of efforts to repopulate corals based on varieties that are temperature resistant?


Humans are not likely to go extinct anytime soon - anything that can wipe out the most adaptable and one of the most numerous and widely distributed species - would leave the Earth uninhabitable to pretty much all higher life forms.

That doesn't mean we can't trash the place or experience massive drops in population.

There does appear to be hope on the higher temperature corals, but I don't know of any plan to actually plant reefs like that. Australia, which benefits economically from tourism to the great barrier reef should take a serious look at it: https://www.theguardian.com/environment/the-coral-triangle/2...


> would leave the Earth uninhabitable to pretty much all higher life forms.

Why are you ruling that scenario out?


I don't see us doing that to ourselves. Climate change won't accomplish that, nuclear war won't accomplish that, biological warfare gone wrong wouldn't likely accomplish that.

I just don't see it happening. That doesn't mean it's impossible.


Anything above around 7 degrees of warming puts the human species itself at risk. Above 3 degrees civilization falls apart. Both of these are within range of possibility in the lifespan of children born today. All it would take is a few more Trump-style presidencies.


I think the OPs point is even then there would still be enough humans around to keep the species going. They probably wouldn't have todays technological benefits, but a few thousand humans could probably survive.


> Anything above around 7 degrees of warming puts the human species itself at risk. Above 3 degrees civilization falls apart.

Could you elaborate/provide links on this? How/why would these happen?


> All it would take is a few more Trump-style presidencies.

I agree with the first statement, but so far, Trump presidency was not exactly a bad thing for the climate.

Economic war with China and renationalisation have positive impacts on CO2 emissions.

Iran sanctions increased oil prices.

Coal subsidies haven't succeeded in reviving the coal industry.

Poor, uneducated families still die from drug overdoses and immigration has decreased, reducing the US population growth.

I know that not all of these things are glorious, but I just wanted to point out that the bigger picture is more complicated than that.


Humans are unlikely to go extinct, but our modern society/lifestyle is very likely to.


I would debate "very likely", but yeah it's modern civilization that's more at risk here. I think it's still an unlikely outcome though.


"...it should be noted that the Earth has been here before and come back from it at the end of the last ice age when sea levels rapidly rose 400 feet and drowned all of Earth's reefs at the time."

No one is seriously arguing that the earth is going to be literally destroyed, despite what anti-science Republicans would lead you to believe.

People are saying "the Earth that we know, love, have co-evolved with will be destroyed, and the assumptions that we built our cities, countries, and societies around will be turned on their heads. This will be replaced with a harsh world with wild extremes, natural disasters in places that aren't built for them, and more intense natural disasters in places that might be used to current, weaker ones.

Perpetuating this willful misinterpretation, even by acknowledging it, is a disservice to the future.


Please don't take HN threads further into political flamewar. It only leads to predictable places and doesn't help.

https://news.ycombinator.com/newsguidelines.html


[flagged]


> Insulting half of the political structure isn't going to help anything

Bear in mind that having 'half of the political structure' maintaining prescientific views re our planet's climate systems has become quite eccentric in 2019 - the US and Australia being the worst offenders. Most of the rest of the world has moved on from outright primitivism to mere obfuscation. Which is some kind of progress, but not enough. Anyway, at this stage the US far right Republican party is now enough of a worldwide laughing stock for insults to potentially be worthwhile. At some point there's a chance that half the US citizenry may come to see themselves reflected back as obscurantist and backward.

> Climate change isn't a new phenomenon. The earth wasn't this magical garden of eden with perfect climate just for us

No, but agricultural civilisation emerged from a background of a relatively stable climate. The range of possible near-term consequences of our current GHG gas emissions include (at scary probabilities, rising as new research comes in) ones that all but eliminate large scale agriculture. This has not been faced in the last 10k years, not with a 7-12 billion population, and not with the additional insults of soil and fresh water loss, habitat destruction, insect population collapses etc. Most ecological scientists are pretty terrified of what's coming at us at this point.




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