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Why are Pakistan’s floods so extreme this year? (nature.com)
164 points by pseudolus on Sept 2, 2022 | hide | past | favorite | 172 comments



"Pakistan is home to over 7,200 glaciers, more than anywhere outside the poles. Rising temperatures, linked to climate change, are likely making many of them melt faster and earlier, adding water to rivers and streams that are already swollen by rainfall."

https://www.vox.com/science-and-health/2022/8/30/23327341/pa...


> climate change ... [glaciers] melt faster and earlier

Yes, this has been strongly predicted by climate models since forever. Mark Lynas' 2006 book Six Degrees, which summarised climate change research up to about 2005, has a section on this.

The prediction was that Pakistan will be wetter (i.e. have higher river flows) than historical averages through the 2020s because of glacial retreat.

Sometime in the late 2030s or early 2040s, the glaciers will be effectively gone, and Pakistan will be without water, except during the monsoon (which may be more erratic - different models still say different things here). The rest of the year, the river beds will be dry.

The time to start planning flood control and water retention structures was 20 years ago. Better late than never, though.


> Pakistan is home to over 7,200 glaciers, more than anywhere outside the poles

It seems odd to give a measure of ice as the count of the pieces.


Kind of, right? But it also makes sense. We might talk about a highly populated country having a lot of cities -- even though cities are just somewhat loosely defined pieces of the population total.


I've never heard of anyone talk of the total number of cities in China, or India, or Indonesia, etc. Where do people talk like that?


See 'List of longest glaciers on Earth in non-polar regions'

https://en.m.wikipedia.org/wiki/List_of_glaciers


57 is much less than 7,200.


Im lost, what unit of measurement would satisfy your doubts about the presence of a lot of glaciers in Pakistan?


A glacier is defined by the valley/valleys it inhabits, it has a locality and flows like a river does. It seems odd to give it a name, but it is no more odd than naming a river.


glaciers do have a certain minimum size, though.


It appears USGS roughly defines it as 0.1 square kilometers [1], or (being American) about 6 Walmarts.

1. https://www.usgs.gov/faqs/there-size-criterion-glacier


> 6 Walmarts?

Supercenter, Discount Store, Neighborhood Market?

So many sizes


Higher temperatures mean more moisture in the atmosphere and aridification at the same time. That's why there can be drought plus record breaking rainfall at the same time.

Plus, when you have drought, it damages the soil and plant life which would normally aid in capturing and retaining the rainfall. And when the rain does fall, instead of being absorbed into the soil it just creates erosion instead as the top layer dies.

People think about soil as just dirt, which it is not. Soil is effectively a living organism (or ecosystem of organisms).


Crazy to think we might actually kill the soil. Imagine a place like mars, because of the soil dies so will everything else.


Reminder that population is Pakistan's population 6x it was at 1950. In 2050 its expected to be 370 million people compared to 37 million in 1950. https://en.wikipedia.org/wiki/Demographics_of_Pakistan


I'm going to go out on a limb here and say that Pakistan's population in 2050 will be closer to 37 million than to 370 million.


This sounds extreme, but it's not as extreme as everyone seems to think.

200M is closer to 37M (+163M) than 370M (-170M).

OP is saying a 10% decrease is more likely than the population staying even.

I disagree - but not as wildly as I would if OP was saying that the population is likely to actually be close to 37M.

200M is quite far from 37M... It's just that 370M is even farther...


I find it more logical think of orders of magnitude, so to compare numbers by dividing them; with 100 sitting between 10 and 1000. Then 200 is a lot closer to 370 than to 37.


Current pop is 220M, already closer to 370 ... I can see it not growing much, but not decreasing.


Climate change caused deaths. Famine, heat, draught, etc.


I'm going to not go on a limb and say that by 2050, the entire population of the world will be closer to 37 million than 370 million.

Mark my words.

100% think this.

That's my futurology projection.


Nukes?


The population of a country peaks a few years after it has gotten developed. As in low child mortality, high educated population, etc.


What countries do you think this is true of? Even, say, France is still growing. Let alone the US.


US birth rate: 1.70 France birth rate: 1.87 Japan birth rate: 1.36 Pakistan birth rate: 3.45

So Pakistan, unlike many more developed countries, has a birth rate higher than the replacement rate, but significantly lower than it’s 1950 to 2000 highs over 6 - and trending downwards.

The population would be expected to drop precipitously, but not soon.


I think Mexico's fertility rate was around 6 in 1975. And is now 2.10 or something. Basically Pakistan is 20 years behind Mexico demographically. Mexico will probably peak in 30 years.

Not sure about Pakistan because a Pakistan of 500 million doesn't seem sustainable.


Your logic is not sound.

As long as birth rate remains above the replacement rate, population will not drop.

Pakistan's birth rate has fallen significantly (but still above the replacement rate), so you will expect population growth to plummet, but not the population number itself


My point is that the current trajectory would soon make the birth rate below the replacement rate.


Are those countries growing with birth rates alone? I thought immigration was what was helping the populations stay stable


The population in most western countries are rising because of births + immigration. If just looking at births alone, then most of these countries would see declining populations.


There is not simply enough food and energy


"Too little, too late" to decimate it with the nukes (



The scale of the flood is crazy. Since the image data is sourced from UNOSAT, I found out more updated data from its website: https://unosat.org/products/


I think it's worth pointing out that the impacts of climate change are often presented as singular effects: rising sea level, warmer summers, increased drought, etc. But as we can see here there is also a very strong interaction effect between all of these (and it tends to magnify the issues rather than having them cancel out).

This is also why many major climate reports tend to inherently be on the conservative side: it's really, really hard to correctly model these interactions so you can only earnestly report the predicted change in individual variables rather than the impact on the system.

And keep in mind this is not the "new normal", we're entering a period of transition that will not end within our life times. The rate of CO2 accumulating the atmosphere is accelerating and the rate of methane in the atmosphere is rapidly accelerating. We will likely see a blue ocean event in the next 20 years and it's really hard to imagine how that will even play out with the global climate, Thwaites glacier could collapse without much warning (very rapidly causing sea level rise beyond our current projections), the AMOC slow down could reach a tipping point, etc.

Everything we're witnessing now will in the future seem relatively mild.


> The rate of CO2 accumulating the atmosphere is accelerating

It's a small point, but the ratio of CO2 on the atmosphere is definitively not accelerating. On the last couple of decades it has been growing steadily, and the noisy few months look like they have negative acceleration.

https://climate.nasa.gov/vital-signs/carbon-dioxide/


I had to look up what a "blue ocean event" was. So, for others, here it is:

https://en.wikipedia.org/wiki/Arctic_sea_ice_decline#Impacts...


I chuckled when I saw your username together with your probably not far fetched but damning prediction of what's to come.


also missing is yet another aspect of a very complex system - parched soil has lower ability to retain water. These floods follow an intense heatwave during which large swathes of pakistani soil dried up. Come the rains and you have a massive problem.

Like you say, this is just the beginning. If floods like this happen in the Indian plains - and they will - the human and social costs will be immense.


we just saw this in the DFW area last week. 3 months of triple digit temps and zero precip followed by a single 24 hour period receiving 5-7" of rain. the ground was so hard, that it might as well have been concrete. that just allowed all of the water to run off into the streams that fed the lakes. fortunately, those lakes were well below normal levels, so this just helped them come back to where they were. if there were multiple days of that level of rain, a la Harvey, we'd have been really screwed.


It's not a foregone conclusion that we're doomed to a life of accelerating climate change. We could deploy solar geoengineering to see us through the transition to renewables. Then, as fossil sources are retired and direct air capture comes online, gradually draw down our geoengineering efforts.

It may seem like a non-starter right now, but what about five years from now? What if our best climate models agree that it will do less damage to the planet than allowing the permafrost to thaw?


I think it's a political problem, not a technical problem. If we can imagine that our best climate models could drive decision making to enable geoengineering... why don't our best climate models drive earlier interventions?


Geoengineering is a unique prospect in that it's inexpensive-- Cheap enough that a couple of billionaires could pay for it if they wanted. In terms of interventions, it's a much easier pill to swallow than something in the trillions of dollars.

The pushback comes from the risk. While we know that it'll cool the planet, we don't necessarily know how it'll affect weather patterns. If we can figure that out with some level of certainty, I believe there will be a point where the rewards outweigh the risks.


I think there are probably several billionaires who independently have the resources the pursue significant stratospheric aerosol injection. I wonder how such an individual would imagine their liability for stochastic effects on agriculture. Those risks make me think it's most likely a government with a nuclear arsenal would pursue this... perhaps India? Mumbai could become a very difficult place to live in a few decades.


That's the whole premise of Robinson's novel Ministry of the future.


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I believe this is one of the largest challenges when trying to make effective changes in the system to address climate change: those whose actions can create the largest changes are not the ones who have to bear the burden first or directly. I really don't know how to appeal to a crowd denying all the evidence, so devoid in empathy for people across the world, while, as an immigrant, I can see my neighboring countries literally drowning.


> I believe this is one of the largest challenges when trying to make effective changes in the system to address climate change: those whose actions can create the largest changes are not the ones who have to bear the burden first or directly.

You mean the corporations and companies that continue to produce emissions on a massive scale while trying to constantly shame me and tell me what a bad person I am for having the audacity to drive to the grocery story once a week or so?


That's an aspect, but the thing I find the most maddening is that people cast doubt on the science by saying that the effects of changing the mixture of gasses in our atmosphere are ultimately not completely knowable. That's obviously true, but to me that's all the more reason why we probably should avoid doing it as much as possible.


I am certain that's part of the psychology. Wealthy people in the colder north know that even if shit hits the fan in poorer and hotter countries, they can pull up the draw bridge and still survive, despite being the people that caused the situation. It's like a long slow genocide perpetrated by a billion people.


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Is there such a thing as "clean gas" and if so, how does Russian gas qualify here?

Also, isn't it Russia that's throttling gas delivery to 20% right now?


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Russia invaded Ukraine. What did the EU do to justify this? I don't mean what Russia's reasons are (NATO expansion) but what morally justifies it.


How about not shutting down German nuclear plants, and not buying "clean natural gas from mother russia".


Beep boop. Not a Russian bot, a German one who is just pissed of by the current politics and the elitist decisions.

And I hate it that any alternative proposed to the current kamikaze politics is called "Russian bots".

Yes, German nuclear plants was yet another trash decision and pushed again by the fear agitated by the Green Party. And yet, the majority wants nuclear, the Greens are against it.

We need REALPOLITIK and not this ideological trash. And REALPOLITIK to beat the biggest thread: global warming... and not some random conflicts between random countries nobody cared about 7 months ago and some random old pseudo-dictators that will anyway not be alive in a few years anymore.


Get natural gas from Canada and the US. North America can supply Europe. Frack in Germany, supply yourself.

You have to choose, is Ukraine worth short term financial pain? The choice is to surrender Ukraine to Russia and take the gas, or suffer for a year financially while you ramp up other energy sources.


Highlighted by the stupidity of not buying directly from Russia at normal prices but instead buying the same hydrocarbons extracted by Russia from war washing third parties like China and India who resell Russian hydrocarbons to those who for political reasons can’t buy directly but can buy indirectly at inflated prices!!

It’s the height of stupidity.


As far as I can tell, e.g. (1), the EU does not get gas from China or India.

(1) https://markets.businessinsider.com/news/commodities/europea...




You're right it seems. Here's a non-paywalled article https://news.yahoo.com/china-reselling-natural-gas-energy-14...


Pretty disheartening to see the downvotes in a forum like hn which are supposed to be informed about these things. If people that are supposed to be able to critically assess data and have access to as much information they need to verify any claims come to the conclusion that you are full of shit, what hope is there to educate grandpa screaming at the wokes on the street.


It is difficult to get a man to understand something when his startup idea depends upon his not understanding it.

–Upton Sinclair, paraphrased


I love technology and have to keep telling my friends that it's possible there won't be a computer industry in 30 years. I'm not joking. Our technology requires a highly complex and organized society to continue to function and develop. Complex and highly organized societies developed under a stable climate. We created societies built on cities that don't move.

If you love technology. If you love computers. Then global warming is your biggest threat and something you should care about deeply.


HN has become very hostile to reality when reality makes people scared.

I no longer expect any thing I say to convince people, but still keep saying what I do so that other people that see it, can feel a little less crazy/alone.

Consider it my, probably futile, struggle against the upcoming wave of cognitive dissonance. As soon as I realized the way things were headed, I also realized that, paradoxically, the more obvious our situation becomes the more aggressively people will refused to see it.

There was a time on HN where downvotes where pretty exclusively reserved for trollish comments and other inappropriate content. I agree with your feeling that this is disheartening, but strangely serves as evidence that these things are happening.

I myself have days where I can't believe my own eyes as I watch events unfolding I thought I would only see at the end of my life if I lived to a ripe old age.


It's not surprising, actually. The problem with very smart people is that they're often very smart in their particular domains of expertise, but socially they will be treated as just very smart in general. This often leads to an emotional overconfidence in assessing fields outside their domains of expertise, and that extreme cleverness becomes more of a tool to create complex rationalizations of uninformed biases rather than being used humbly, empirically, and diligently as should be the case for a beginner in any topic.

And yes, I'm aware that's essentially a paraphrase of the Dunning-Kruger concept. We're all probably making similar assumptions about domains of knowledge we don't know much about, because that's what the brain does. Just like human vision appears solid and complete but is actually a stitched together amalgamation of the small, receptor-dense fovea in the center darting around constantly, and the rest being filled in by the brain instead of direct perception, so is our impression of the world, and we won't know things for sure unless we take time to study them up close.


I read someone else suggest Permaculture as a way of mitigating some of the affects of monsoons in these types of areas.

Does anyone have any evidences of such a thing working?


Probably the best documented example of it working is in the Loess Plateau in China. John D Liu has a couple documentaries on it, here is one: https://youtu.be/IDgDWbQtlKI

A good example of a similar project in India, as covered by Andrew Millison: https://youtu.be/jDMnbeW3F8A

Sepp Holzer did a similar project in Portugal: https://www.youtube.com/watch?v=OUryneCjxV4 ...I believe he also did some pretty large projects in the middle east, but I can't find any vids on them at the moment.

Geoff Lawton has done a ton of projects like this, but maybe not at the landscape wide scales like the projects above.

Probably the best book on the basic principles of how to do it - Rainwater Harvesting for Drylands and Beyond by Brad Lancaster. Also the book Water For Every Farm by P.A. Yeomans is pretty good as well, but not as accessible of a read.

TLDR - To keep desert monsoons from flooding areas downstream, dig a landscape wide network of swales and basins to catch, soak and sink the water into the soil. Properly dug, such earthworks recharge aquifers while stopping flooding and erosion.


I can't see how it could help having tons of plastic also floating in the river and expensive gravel filling the river bottom. The best way would still be to work with the monsoon, not against it.

But maybe I'm not understanding the solution. Can you explain more the idea?


Permaculture has nothing to do with tons of plastic nor gravel filling the river bottom.

Permaculture is: the development of agricultural ecosystems intended to be sustainable and self-sufficient.

I presume GP meant that by having more persistent vegetation in the area, that vegitation would do vegetation things and help with flood control.


I see, I was thinking in hydroponics, both terms are often associated.

I'm sceptical when I see agriculture wrapped in hype terms. I think that engineering will play a bigger role here. Forest restauration and dams that would retain soil and water and absorb part of the hit will help.

Just to speculate about possible partial solutions, I think that in plain areas subject to frequent flooding they could erect small hills and build the houses over those to defend homes. As floods will increase in the future, the sooner they start, the better.

They could also to dig a system of storm ponds. So will have many soil to build the hills. Moving soil can be done in the same step. The base of the hills should be heavily reforested to retain the soil in place. As a bonus you increase the forested area and help nature to flourish.

The other solution would be to dig concrete canals for as water highways but that would remove the main reason why people lives there: Very rich soil for agriculture plus water. You don't want all of this water lost in the sea

Storm ponds would play a benefit role to store water for the dry season also.


Sounds ridiculous on its face, and that is as a practitioner of permaculture. I couldn't really get my head around how it could possibly make even a slight dent against the massive flooding witnessed here.


When Gabe Brown switched from conventional agriculture to regenerative agriculture, he increased water infiltration in his soil from 0.5 inches (1.25cm) per hour to 30 inches (75cm) per hour. So imagine if he and all his neighbors had the same beautiful soil -- flooding just couldn't happen.

I haven't seen a list of such measurements from permaculture, but I know it can be used to regreen deserts (as shown in Jordan, Saudi Arabia, Arizona and elsewhere). And I assume permaculture vastly increases water infiltration. Geoff Lawton has videos showing Zaytuna Farm happily surviving drought and flood alike.

If farmers switched from conventional agriculture to some combination of regenerative agriculture and permaculture, most flooding would be prevented. Their own fields would easily infiltrate rain, eliminating runoff that builds up into flooding.

The article mentions that in addition to Pakistan getting double the normal amount of rain, increased glacier melt is filling the Indus river. I assume that in the theoretical situation of all farmers in Pakistan practicing regenerative ag or permaculture, that land on the Indus would flood. But not 1/3 of the country as we're seeing now, and the flooded areas would recover faster.


Water infiltration is measured by digging a small hole, filling it with water, and seeing how fast it drains. There's no way that regenerative agriculture has changed soil composition multiple feet down, which is what would be needed for the soil to absorb multiple feet of water.

I went to check the above sentence, and the first hit was this detailed article from Washington State, which analyses Brown's claims in detail, and explains why the scientific community is skeptical of them:

https://csanr.wsu.edu/regen-ag-solid-principles-extraordinar...

Anyway, even if, as Gabe Brown claims, regenerative agriculture is an order of magnitude more effective than expected, and you applied it to 100% of the land in Pakistan, it would still only reduce flooding by less than a foot.


> Water infiltration is measured by digging a small hole, filling it with water, and seeing how fast it drains.

Informally yes, but the scientific way is to use a ring infiltrometer: https://www.fao.org/3/s8684e/s8684e0a.htm -- Basically instead of digging a hole, you pound a pipe into the ground and then fill the pipe with water.

As for agricultural practices being able to change soil composition multiple feet down, trees and tap-rooted plants are very effective at placing large volumes of organic matter at depth. One example, Lacy Phacelia (Phacelia tanacetifolia) is an annual plant that produces a dense fibrous root system that reaches a depth of 4 feet; in the fall the Phacelia plants die, and their roots decompose at depth, creating pathways for water infiltration while also increasing soil organic matter at depth. The same goes with other trees and shrubs. The farmer from the "It ain't much but it's honest work" meme, Dave Brandt, has some really enjoyable presentations on youtube about improving soil composition at depth.


> . There's no way that regenerative agriculture has changed soil composition multiple feet down

How do you know that?

How deep do roots go? Do worms dig? Do you know?

I do not. But I am not making assumptions


Read the article I cited.


Any link to read about this 0.5 - 30 inch/hr conversion? Cultivated soil or already wetted soil will absorb much more readily than not, was this a carefully controlled experiment? Anyway it would take some serious modelling not handwavy yes or no as to whether permaculture/regenerative techniques (and a well defined definition of success of mitigation) could work. I absolutely admit that it could help on the margins, but would it have really have changed the image featured in this comment: https://news.ycombinator.com/item?id=32692060 ? Is the supposition that this water would find its way to some aquifer?


> Any link to read about this 0.5 - 30 inch/hr conversion?

Read From Dirt to Soil by Gabe Brown. He also mentions the first inch (2.5cm) infiltrates in 9 seconds! So his soil drinks up more water in 9 seconds than nearby farms do in an entire hour.

> was this a carefully controlled experiment?

NRCS water infiltration tests.

https://www.nrcs.usda.gov


Check out: Treating the Farm as an Ecosystem with Gabe Brown Part 1, The 5 Tenets of Soil Health https://www.youtube.com/watch?v=uUmIdq0D6-A

His neighbor's farm floods, his land soaks it up like a sponge.

Year-on-year his topsoil gets deeper.


Living in similar conditions in Florida, I know at about 4 inches per hour on a plain, you're screwed. It floods badly. And we have excellent drainage systems.


Maybe even relatively simple but massive reforestation efforts could help mitigate climate change effects in the long run.


Forests are not very good carbon sinks except in the short run.

They have three problems when used as carbon sinks:

1) They tie up land for one, otherwise, non productive purpose (the wild species living in them do not mind that, must be said)

2) Once fully grown they reach a carbon balance. This can happen surprisingly quickly, a few decades.

2) Forests do not simply sit there like a rock. Eventually they will burn unless managed. Then they simply release all that stored carbon into the atmosphere.

Regenerative agriculture is a much better carbon sink. The process of storing the carbon increases the soil fertility so it is a win/win. Soils can get very deep so there is not a natural limit like for forests.

A draw back is measuring the carbon sunk. I do not know of anybody doing that (a market opportunity?). An important part of carbon farming is selling the "carbon credits" (a mad bad and sad idea, but it is a thing) to do that there must be an accepted measure of carbon sequestration, like there is for trees.


Agree but don't forests do much more for weather events than being carbon sinks?

AFAIK they also create a more moderate micro climate, reducing soil temperature, retaining humidity and rain while keeping it in the soil, reducing the risk of draughts.

Of course regenerative agriculture is much better but the effort to implement it at a scale is incomparably greater, while it should not be shunned.

Also agroforestry will help with making agriculture possible in larger areas of land.


At least over here, trees grow for centuries. Big trees survive forest fires as well.

Not a short term carbon sink only.


Gabe Brown's work is primarily on improving soil health, not on earthworks for flood prevention, aquifer recharge, etc. His gains in rainwater infiltration is a secondary effect of the steps he's taken to improve his soil.

In terms of projects whose primary aim is flood prevention / aquifer recharge, John D. Liu, Andrew Millison, and Geoff Lawton all have documented quite a few projects that have been very successful in addressing the problem.


naive q: does that still help if the aquifer gets saturated?


Is an aquifer ever likely to get saturated? I have no expertise in this area, but in the US at least the concern is always over aquifers being depleted, not so fully saturated that they can't absorb more water. My understanding was that it takes very long time for water to actually get from ground level down into an aquifer.


At some point the ground cannot accept anymore water, no matter what.

Proof: oceans exist.

The key to the whole thing is if you can slow it down enough so that a sudden deluge over a day/week/month has time to slowly drain out.

Getting water into an aquifer takes time depending on how the soil is, but eventually the aquifer would rise to the surface and you'd have a marsh. Or it would rise higher and you'd have a lake.


This depends entirely on where you live. Sure in the Southwest, there's a big problem with drought. But along the Gulf Coast, the water table is astonishingly close to the surface. When my family put in an in-ground pool in Louisiana, they had to start filling the concrete pool with water even before finishing it because if they left it empty, the surrounding water table would push it up out of the ground like a floating boat.


Yeah just imagine if a billion people completely changed their way of life.


I'm not sure if you're being sarcastic or not. Climate change is going to require changes of at least that scale, whether we reduce emissions or not.


Luckily for humanity that won’t actually be necessary.

In the next 20-30 years I suspect we’ll just moderate total solar irradiance as-needed by injecting moon dust into L1.

The only issue is if there are powerful countries that are actually benefiting from the warming and don’t want to cool it down bit.


Luckily for humanity that won’t actually be necessary because in the next 20-30 years we're likely to revert to savagery and barbarism, and "civilized" behaviors won't matter anymore (assuming one of our "leaders" doesn't do the epic stupid and get us all "nuked" out of existence).


I think that's pretty easy if government incentives are in place.


Imagine if they don't.


permacultures are some super carbon sinks, anti-erosion systems, absorption systems and organic food producers, each one is just a grain of sand (https://en.wikipedia.org/wiki/Sorites_paradox), but many grains do the job along with lifestyle changes


The more water that is retained on the property, the less that is available for entering streams.


Lots of small water retaining walls and pits makes it so it doesn’t run off and accumulate in some low central area.


no mention of the Hunga Tonga–Hunga Ha'apai eruption?

It sounds like that eruption at least changed atmospheric composition by throwing tons of water into it.


https://link.springer.com/article/10.1007/s00376-022-2034-1

Unlikely. At least a single volcanic eruption is not enough to change the long-term climate trend, you need a clusters of eruptions to persist through centuries for that. HTHH will likely decrease the global mean surface temperatures by 0.004°C in the first year.

Compared to that human activity is a thousand times more significant, everything else is statistical noise next to it, which at least means that it is easy to spot.


> At least a single volcanic eruption is not enough to change the long-term climate trend, you need a clusters of eruptions to persist through centuries for that.

https://en.m.wikipedia.org/wiki/1883_eruption_of_Krakatoa

“ The eruption caused a volcanic winter.[17] In the year following the eruption, average Northern Hemisphere summer temperatures fell by 0.4 °C (0.72 °F).[18] The record rainfall that hit Southern California during the water year from July 1883 to June 1884 – Los Angeles received 970 millimetres (38.18 in) and San Diego 660 millimetres (25.97 in)[19] – has been attributed to the Krakatoa eruption.[20] There was no El Niño during that period as is normal when heavy rain occurs in Southern California,[21] but many scientists doubt that there was a causal relationship.[22]

The eruption injected an unusually large amount of sulfur dioxide (SO2) gas high into the stratosphere, which was subsequently transported by high-level winds all over the planet. This led to a global increase in sulfuric acid (H2SO4) concentration in high-level cirrus clouds. The resulting increase in cloud reflectivity (or albedo) reflected more incoming light from the sun than usual, and cooled the entire planet until the sulfur fell to the ground as acid precipitation.[23] “.

Yes, I’m aware of “but many scientists doubt that there was a causal relationship” regarding the rain but the climate has been affected by a single eruption.


GP said "long-term climate trend" and then mentioned centuries. Yes, an especially large eruption can influence things for a year or two. But then the effect settles out.


Well this flooding is occurring 8 months after the eruption mentioned so it seems a reasonable question to ask.


Ah, fair. A single eruption will not perturb the long-term trend, but we're discussing the short-term incident in Pakistan, and a single eruption can have notable short-term impact. (I don't know anything about whether the specific eruption in question could have any impact on this specific crisis in Pakistan.)


Also https://en.wikipedia.org/wiki/Year_Without_a_Summer with Mount Tambora

There's good evidence this has happened multiple times in history by a single eruption.


That was the consequence of at least two eruptions, one of which emitted up to 60 Tg of sulphur dioxide. HTHH only emitted 0.4 Tg.

It is not impossible that HTHH affected the monsoon, but there is a thousand pound elephant in the room that will make it's effect hard to quantify.


Human activity is responsible for less than 5% of greenhouse gasses. One eruption can spew decades worth of gases into the air


This is misinformation. Volcanoes are responsible for less than 0.5 Gt of the global CO2 emissions a year. That's a bit less than the 50 Gt we are responsible for. Volcanoes and solar flares would have caused a slight cooling in the last 100 years, not a sharp warming we are experiencing.

There is a natural carbon cycle, which is quite balanced in that there is barely any radiative forcing, which is the difference between how much energy enters the atmosphere and how much of it leaves. Human activity amounts to all, I repeat all of the radiative forcing in the last century, and more actually, because naturally there would have been negative forcing.


It’s not misinformation. We don’t have major eruptions every year. And only 5% of annual carbon emissions are anthropomorphic.

I agree humans are responsible for increasing CO2, but not because of emissions. The earth should act as a buffered system, with utility of atmospheric carbon rising with carbon levels.

There’s another paper in nature describing how the mass slaughter of baleen whales broke the iron cycle at the poles. Mass whale poop fed the krill who are critical to fixing iron…the high iron krill poop is what feeds the plankton blooms. Polar plankton was critical to sinking excess atmospheric carbon.


It's misinformation because the natural carbon cycle adds and removes CO2 that keeps a balance. Around 750 Gt of carbon moves through the carbon cycle each year, and the keyword here is that it moves through. The natural emissions are always counterbalanced. The biological pump is one of the most important part of this system, which evolved to work like this.

Unfortunately as it turns out this system can't cope with the extra emissions. Most of it is still absorbed, but a lot of it lingers in the atmosphere, causing trouble. Even the oceans have trouble absorbing the extra emissions. They now threaten the biological pump itself.

This is why people are so depressed when it comes to climate change, because never mind the greenhouse effect, which is in itself substantial, but once you screw with things like the biological pump there is no telling what will happen. This is a big, fine-tuned system, not unlike a spaceship. It is very risky to poke it. Granted it is likely that the system will snap back into working conditions in a few million years, but that's not exactly reassuring for us.


The krill - whale poop cycle was the fertilizer that fed the mass algae blooms in the Arctic that sink increasing emissions. That’s the point. It isnt burning fossil fuels that is the problem… it’s the fact that polar algae is way below normal levels because of a lack of nutrients due to the lack of baleen whales

https://www.academia.edu/314989/Southern_Ocean_iron_fertiliz...

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4254789/


Not directly, though I can't guess at indirect effects. If 100% of the water from that landed in the flooded area of Pakistan, it would've only added 2.6 mm:

http://www.wolframalpha.com/input/?i=146%20million%20cubic%2...


I had only been alluding to indirect effects - an increase in the greenhouse effect, which certainly would raise temperatures (and increase the amount water air can hold).

I think we will find that, even during an increase in anomalous years from climate change, 2022-2023 will be anomalous.


In that case I certainly wouldn't be surprised either way. IIRC the altitude of the water makes a difference.


Do you have any sources that discuss this?


The undersea eruption also ejected 146 million tons of South Pacific Ocean water into the stratosphere.[56] The amount of water vapor ejected was 10 percent of the atmosphere's typical stock.[57] It was enough to temporarily warm the surface of Earth. This water vapour was estimated to remain for 5–10 years.[55]

https://en.wikipedia.org/wiki/2022_Hunga_Tonga%E2%80%93Hunga...


Interesting as water vapour is in itself also a greenhouse gas.


Thanks for sharing this. That certainly is a lot of water.


10% of the stratosphere's typical stock.


If true, the article should be changed. Isn't the stratosphere extremely dry?


Yes, that's why a single eruption can have a noticeable effect.

Stratospheric water may also set the upper limit on how many launches to orbit can be done per year, since all the propellant consumed in or above the stratosphere makes water that ends up in the stratosphere.


How would it limit launches?


You would not want to make so many launches that it perturbed the climate, due to water vapor increase in the stratosphere. We are nowhere close to this happening yet at current launch rates, btw.


[flagged]


You could always click on the source that Wikipedia has literally next to the sentence.

https://www.nature.com/articles/d41586-022-01544-y/


Wikipedia is generally a great summarization of a topic and links to numerous sources - that is usually a more valuable thing to link than an opaque research paper.


The sources are in footnotes. The quote even contains footnote references.


Here's a practical examination of what effect the 10% increase in stratospheric water vapor caused by the eruption has on global weather: https://www.severe-weather.eu/global-weather/cold-anomaly-st...


While it's absolutely true there is a confluence of factors here (eg glacial melt, heat wave and a depression) and that these events are more likely with global warming, I'm disappointed this article didn't cover another important factor: dams.

Flooding used to be a much bigger problem in the Western United States and it was solved with dams. Yes, there is thd risk of dam failure but we're weighing up the real and present risk of flooding regardless against the possible risk of dam failure.

Unfortunately, there has been increasing opposition from the environmental lobby against building dams in the developing world in recent decades (eg [1]) and this matters when such countries are usually dependent on the World Bank and/or IMF to fund their construction.

Dams not only reduce the risk of extreme flooding but also provide cheap hydroelectric power, which is of incredible value to a developing nation.

Pakistan has some dams but clearly not enough. Given these extreme events that led to this catastrophic flooding are increasingly common and that no action in climate change will change this in the short or even medium term, it's time to build dams. Lots of them.

[1]: https://www.theguardian.com/global-development-professionals...


its possible we didnt look at the same flood map or i'm looking at it wrong, but the way i read it it says that >5% of the country is flooded. Thats beyond the scope of dams to handle i believe.


dams work well in regions with limited rainfall. The indian subcontinent receives most of its annual rainfall during the monsoon. Periods of 100 mm/hour of rainfall are not uncommon. Annual rainfall numbers in southern asia are often 1000 mm. North america's closest regions with that level of rainfall are all west of the rocky mountains.

Dams are unlikely to help here and pose a serious risk if they break - which they can in a region prone to earthquakes.


Dams destroy ecosystems, reduce biodiversity and often just silt up. A related but far better idea is to encourage water retention on a far bigger scale by building johads or berms everywhere. See the Paani foundation's work in next door India.


We need to airdrop more beavers, clearly.


This might actually not be a bad idea. That being said I think a lot of the environments would be too dry for beavers and not contain enough trees. Or conversely be too alpine.

So basically we need genetically engineered super beavers that are adapted for high altitude mountaineering.

On another note I find it hilarious and also cruel that beavers are apparently absolutely obsessed with stopping the sound of any running water. To the point that if one wanders near your home and can regularly hear water running inside of pipes it drives them crazy.


Using naturally skilled animals to pick up where we humans either fail or deny an issue is something we should seriously consider as a hedge at this point. If we can get extremely rich people even more rich by doing so, we may have a chance at it catching on.


Climate change is real and has changed the temporal distribution of rainfall, often increasing the interval between rainfalls, while also increasing the amount that falls, during rainy periods.

Longer durations of 'no rain' cause the ground harden to a much less porous, concrete-like surface that cannot absorb the rain, when it does come, fast enough. So the water pools and flows, causing flood conditions.


The article also blames high amounts of glacial melt (to the point of bursting through glacial dams) sending a lot of extra water through waterways in a short amount of time.


With all due respect why are Glaciers melting in August.. or July or June. April and May are hot as hell in Indian Subcontinent.

edit: glaciers melt in summer, I am surprised why they are melting in rainy season. No matter how you vote, just explain why this odd behavior.


Why is that odd? Ice melts when it's warm.


Because you would have signs of glacial melt ahead of time. You would know in may if not June. Not in end of august.


Except it has happened about every 12 years throughout history

The ancients even created a name for it: La Nina.


Huh, I didn't believe you at first but apparently there was indeed very severe flooding in 2010, and again in 1992.

That said, back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before


> back in 1992 this only affected 3 million people, and now it's 30 million. The population of the country only doubled over the same time span, so it seems like this year's flooding is easily five times worse than before

Or the distribution of people living in the flood plane drastically changed in that period. See my other comment @ https://news.ycombinator.com/item?id=32653203


Land-use matters. I don't have a good link but there has been reporting on the topic.

e.g. https://www.reuters.com/article/us-pakistan-environment-fore...


Maybe the increase of population was mostly in affected areas, not 5 times worse.


Except this is our third La Nina year in a row, the first time that's ever happened:

https://www.reuters.com/business/environment/wmo-forecasts-f...


What?

We had a triple dip in 1998, and before that 1976.


Also 1954-57.


That article only says it’s the first this century.


As long as you define century as 2000-2100, and not 1922-2022...


“This century” is fixed to start at 2000 until 2100, same as this decade is 2020–2029.

“Last hundred years” for the former interpretation.


Or 2001 until 2101, if you're being pedantic about the Nth century AD/CE.

(Because there is no year 0 in the AD/CE calendar, so the first century in the calendar starts in year 1, the second in 101, etc...)


That is how "this century" would typically be understood


Whatabout this thing that can happen at the same time as the climate changing due to human pollution?


"You have two life lines left: 50/50, and ask the audience"

"I'm gonna go with A. Climate change "


Climate change has made us all incredibly intellectually lazy. Literally anything happens and we don't bother trying to understand why past "climate change".

Natural disaster? Climate change. More or less insects/birds/rodents than usual? Climate change. More or less rain/snow/hail/heat/cold/storms/floods/droughts than usual? Climate change. Wildfire? Climate fire. Crypto currencies using record breaking amounts of electricity year over year? Climate change (impoverished countries ravaged by climate change turn to crypto currencies to escape their local inflated currency which further exacerbates climate change in a positive feedback loop - see what I mean?).

In all of these cases climate change may indeed be a piece of the puzzle, but due to intellectual laziness it has become the vast majority of the pie and we don't bother to understand if there are other factors more influential than climate change.


Yeah, a drastic change on one of the most important aspects of the biosphere on the entire world is prone to lead to all kinds of changes.

Usually people do go and verify, it's probably you that are not prone to looking. Almost always, it is global warming. This one time, we are not waiting for anybody to verify, because 50 years ago people were already predicting that global warming would almost certainly cause floods on the South littoral of Asia.


Climate change is happening and most of us live in a country (or next to a country, yay Canada!) where half the political body actively denies that it is happening and refuses to take action.

As long as half of America continues to engage in such dangerous denialism there is no amount of drum beating that is excessive.


There are so many things factually incorrect here

> most of us live in a country

No we don't

> here half the political body actively denies

By actively deny, you mean that they force everyone like you? If you mean that, then it's factually wrong.

> no amount of drum beating that is excessive.

Umm, as a suggestion you should look for more effective way of convincing people.


Yes, I really wish that there is some place for nuanced discussion regarding climate change. I think most would agree that any single event can't be attributed to climate change just we could only look into average frequency.


Persistent corruption and poor management.


climate change.


Because rains been going on for so long this years. Heavy rains went for 2+ months so far across different parts of the country.

Way longer that 1-2 weeks intense monsoon downpour.


I clicked back through the years available for my city on weatherspark.com

Back in the 90s, never above 90-91 in Sept.

In the last 10 years we started seeing 94-95 in Sept.

Coincidentally air travel has doubled in that time period; from 2.25 billion people flying in 2010 to 4.56 billion in 2019. Of course that cratered since 2020.

Thanks AirBnB and other apps that make burning fossil fuels a thoughtless, trivial thing?


> Thanks AirBnB and other apps that make burning fossil fuels a thoughtless, trivial thing?

Your outrage is misdirected to something you probably personally relate to. Leisure travel is a minuscule component of the carbon in the atmosphere. Leisure travel is a fly hitching a ride on the beast that is global logistics, and AirBnb making leisure travel slightly cheaper and easier is a drop in the bucket for all leisure travel in general.


“Outrage”.

Your qualification of my emotions is way off.

2.4% when talking tonnes may be a small percent relative to the “big picture” but it’s not 0 tonnes, it has an impact, and production of machines to produce planes, production of more planes to keep up with rising demand are not included in that 2.4%. Leisure travel across the planet is not exactly a requirement for the survival of the species.

It’s still pushing our choices onto future humans.

Since statistics are what matters to you; you’re one of seven billion; your perspective is not that important.

Probably best to avoid overly reductive rhetoric, the basis of which (statistical relevance) can be easily used against you. More co2 is released in service of the airline industry than just planes flying. The world is not made of singular statistical objects in a vacuum.


I doubt people going on a vacation a couple times per year is even a line item in the list of causes of burning fossil fuels. However, at the beginning of the pandemic, with fewer cargo vessels and even fewer personal vehicles burning fuel, we saw a measureable improvement to the environment within days.


The planes in the air are not the only release of co2 required to provide air travel.

There’s an industrial pipeline of machines to mine materials and machines to produce planes, all the travel to and from airports. The drink service carts don’t just fall from the sky or grow on trees, they too have an entire industrial pipeline required for their production. Making travel easier puts more strain on planes necessitating more parts and net new planes sooner.

The world is a miasma of statistics making up “the big picture”.


I'd love to see nature write an article about why a certain part of the world has had such unusually moderate temperature and precipitation of late. Also, if you want to search the whole globe for something extreme happening, you're guaranteed to find it in spades.


What does this even mean? Are you denying that climate change is a thing? Now? In 2022?


A sadly prevalent line of rhetoric here on HN. We could be living on venusian Earth and some HN pedant would be splitting hairs


waiting for absolute apocalypse before taking up a curious mind about it


Here's what the temperature anomaly looks like for "the whole globe" https://www.youtube.com/watch?v=haBG2IIbwbA


For example, if you search through the whole globe for people holding extreme anti-science views denying climate change in the face of overwhelming evidence, you'll find literally millions of them.




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