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Why are Pakistan’s floods so extreme this year?

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Re: Why are Pakistan’s floods so extreme this year?

#61

Post by hackerlight »

polygamous_bat wrote: post #49
hotpotamus wrote: post #39

Earlier quoted context omitted.

Quoted post unavailable.

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 countrie…

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.

Re: Why are Pakistan’s floods so extreme this year?

#62

Post by prpl »

ben_w wrote: post #52
prpl wrote: post #4

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.

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.

Re: Why are Pakistan’s floods so extreme this year?

#63

Post by nerdponx »

asah wrote: post #59
Panino wrote: post #36

Earlier quoted context omitted.

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,…

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.

Re: Why are Pakistan’s floods so extreme this year?

#64

Post by andyjohnson0 »

"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...

Re: Why are Pakistan’s floods so extreme this year?

#65

Post by aeternum »

mring33621 wrote: post #50

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.

Except it has happened about every 12 years throughout history

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

Re: Why are Pakistan’s floods so extreme this year?

#66

Post by ben_w »

prpl wrote: post #62
ben_w wrote: post #52

Earlier quoted context omitted.

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.

Re: Why are Pakistan’s floods so extreme this year?

#67

Post by Panino »

peteradio wrote: post #55
Panino wrote: post #36

Earlier quoted context omitted.

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,…

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,…

> 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

Re: Why are Pakistan’s floods so extreme this year?

#68

Post by handoflixue »

aeternum wrote: post #65
mring33621 wrote: post #50

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.

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

Re: Why are Pakistan’s floods so extreme this year?

#69

Post by MrRiddle »

handoflixue wrote: post #68
aeternum wrote: post #65

Earlier quoted context omitted.

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

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

Re: Why are Pakistan’s floods so extreme this year?

#70

Post by alexose »

AftHurrahWinch wrote: post #54
alexose wrote: post #37

Earlier quoted context omitted.

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…

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.

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