Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

So, how do you refill an aquifer?

heatmap.news

Post reply on HN
Print view View original

21–30 of 95 posts

Re: So, how do you refill an aquifer?

#21

Post by qzw »

Throw73849 wrote: post #15
vkou wrote: post #10

Earlier quoted context omitted.

The greenhouse coefficient of water vapour is, pound-for-pound, about one hundredth that of CO2. There's also no meaningful amount of water that can be sequestered, given there's about 10^18 tonnes of it in the world's oceans.

It may be still more efficient to pump water underground. Isolating CO2 is very energy intensive, for the same amount of energy we may isolate 100x more H2O. Sometimes it even condenses spontaneously! There is also huge amount of natural CO2, single vulcano eruption... It is about reducing green house gas emissions generated by humans. And there are many artificial lakes, fields and forests that generate huge footpri…

Clippy: It looks like you’re trying to turn Earth into Arrakis. Would you like some help with that?

More seriously though, as the effects of climate change intensify, I think it’s all but inevitable we’ll have to seriously look at manipulating whatever environmental factors we can in order to counteract the worst of them. Maybe we can’t do much about the sea level rise, but maybe it would be possible to moderate storm and drought/flooding intensities. As you pointed out, water vapor levels may be one of the easier things we could manipulate, as least on a local or regional scale.

Re: So, how do you refill an aquifer?

#22

Post by nvahalik »

HPsquared wrote: post #16
Throw73849 wrote: post #9

Some projects are pumping CO2 underground to reduce global warming. Water vapor is a greenhouse gas. Maybe we could use some of that money and equipment, to pump water underground!

Water vapour is a greenhouse gas but, confusingly, clouds can have either cooling or warming effects. The interactions are pretty complex.

> clouds can have either cooling or warming effects

Just in case anyone is wondering... one of the simplest interactions has to do with daytime and nighttime cloud cover.

Daytime cloud cover causes shade, which _can_ lower temps below the clouds. At night, heat from the ground radiates up and clouds can block the radiated heat. This is why cloudless nights during winter are colder, and cloudy summer nights can be stifling.

Re: So, how do you refill an aquifer?

#23

Post by gus_massa »

Throw73849 wrote: post #9

Some projects are pumping CO2 underground to reduce global warming. Water vapor is a greenhouse gas. Maybe we could use some of that money and equipment, to pump water underground!

The amount of water in the air is almost impossible to change because the evaporation and condensation keep the balance "constant". It actually depends on the average temperature and other factors so it's not a real "constant", but unless it's possible to cover all the seas it's impossible to reduce it.

The amount of CO2 changes more slowly, plants and cyanobacteria and some minerals absorb it, but it's a slow process. Natural decomposition, fires and fossil fuel power plants release it, but it's a slow process.

So it's easy to modify the CO2 amount in either direction. Burning fossil fuel to produce energy makes a lot of money. Carbon capture requires a lot of money. So you can guess which one is wining now.

Re: So, how do you refill an aquifer?

#25

Post by somat »

vkou wrote: post #10
Throw73849 wrote: post #9

Some projects are pumping CO2 underground to reduce global warming. Water vapor is a greenhouse gas. Maybe we could use some of that money and equipment, to pump water underground!

The greenhouse coefficient of water vapour is, pound-for-pound, about one hundredth that of CO2. There's also no meaningful amount of water that can be sequestered, given there's about 10^18 tonnes of it in the world's oceans.

My understanding is it is the other way around, that in equal concentrations water vapor has a much stronger greenhouse effect than carbon dioxide. However for physics reasons the atmosphere does not hold much water vapor.

In fact if I understand correctly this is the mechanism for a runaway greenhouse, that is, something like what happened to venus. Warmer temps allow for more water vapor in the atmosphere, due to it being such a good greenhouse gas, temps then build out of control as more and more water is vaporized.

https://en.wikipedia.org/wiki/Greenhouse_gas#Role_of_water_v...

Re: So, how do you refill an aquifer?

#27

Post by SkeuomorphicBee »

Some regions in India with wet and dry seasons have been successfully doing this for some time now. Interestingly, the very high precipitation during the wet season allowed them to achieve improvement without megaprojects, instead focusing on outreach campaigns to teach many small farmers to build recharge wells and water slowing features (frequent small dams) on runoff streams on their land to foster ground absorption during the wet season.

Re: So, how do you refill an aquifer?

#28

Post by dylan604 »

meristohm wrote: post #2

Permeable pavement sounds interesting, and I wonder how safe it is (the bottom of the fractional-distillation barrel might have fewer volatiles but do we want more surface area of the stuff to come into contact with water?) and how quickly it gets clogged. Also, beavers: they're great at slowing the flow of water across a landscape, giving the water time to recharge aquifers. We'll need to address how we use land, th…

My concern for urban permeable pavement is all of the chemicals that would be absorbed with it. Same with the forced injection of water back into an aquifer. I was under the impression that the water being pulled through the ground is a filtering process so that the water in the aquifer is clean.

Re: So, how do you refill an aquifer?

#29

Post by gaoshan »

In the case of a place like Florida, parts of the gigantic aquifer that extends under that State and up in Georgia get backfilled by brackish water once depleted below a certain level and this effectively destroys it, preventing refilling or refreshing because of the salt content that gets introduced.

Re: So, how do you refill an aquifer?

#30

Post by indus »

There is a California-specific law called the Subdivision Map Act that requires cities/counties to have provisions for parks when approving new subdivisions and housing.

The specifics of this is super convoluted and left to the interpretation of the city and its planning done at the county.

What would be amazing is to add a certain percentage to lakes and ponds when new parks are created--and not just green field.

Hope someone can lead and get this amended.

Post reply on HN