Some of the World's Biggest Lakes Are Drying Up • Hacker News Board

Re: Some of the World's Biggest Lakes Are Drying Up

#11

Post by thaumasiotes » Sun, Mar 04, 2018, 2:09 AM UTC

libertine wrote: post #3

You don't need to go to South America, Asia or middle East - it's happening in Europe and no one seems to notice. Look at Portugal and Spain, it's becoming a desert - the day of the cold wave the south of Portugal and Spain had the same temperatures of some country's in Africa.

> the south of Portugal and Spain had the same temperatures of some countries in Africa

Tropical Africa, or are you saying the temperature in the south of Spain was comparable to the temperature in Morocco fourteen kilometers away?

Re: Some of the World's Biggest Lakes Are Drying Up

#12

Post by goldenkey » Sun, Mar 04, 2018, 2:10 AM UTC

joncrane wrote: post #7

Where is the water going, though? Isn't water a zero-sum game in the sense that Earth is a closed system?

Not exactly. Ocean water isn't usable without removing the salt and other solutes. When a lake or river dries up, it may lose its bedrock and therefore, even when it rains again, the river no longer holds water. So you end up with the water spread out over land, which is useless - because we don't have tree-like roots to just suck low density water out of the ground. We rely on large pools to be efficient.

Re: Some of the World's Biggest Lakes Are Drying Up

#13

Post by narag » Sun, Mar 04, 2018, 2:23 AM UTC

libertine wrote: post #3

You don't need to go to South America, Asia or middle East - it's happening in Europe and no one seems to notice. Look at Portugal and Spain, it's becoming a desert - the day of the cold wave the south of Portugal and Spain had the same temperatures of some country's in Africa.

Spain mainland is separated from Africa by a mere 14 km strait, so no wonder temperature is similar, not talking about Canary Islands that are like a thousand km further to the south.

Southwest mainland is becoming a desert indeed, but that's nothing new. Most classic spagetti westerns were filmed there.

It's Sahara crossing the sea and a good thing for "plastic sea" (greenhouses). Almería provides several vegetables harvests a year that our European neighbourgs appreciate very much.

Just 200km west, you have permanent snow and big woods.

Re: Some of the World's Biggest Lakes Are Drying Up

#14

Post by woodandsteel » Sun, Mar 04, 2018, 2:24 AM UTC

teslabox wrote: post #8

How much of the missing water is actually due to higher temperatures, and how much is due to people siphoning water from the aquifers that feed the lake? This article mostly focuses on "climate change" hysterics, but also acknowledges the siphoning problem. A HN comment [0] linked to a TucsonWeekly [1] piece about how Tucson used to be an oasis. Similarly, the Salt River used to run year-round through Phoenix. Las Ve…

>This article mostly focuses on "climate change" hysterics

So what is your view on climate change? Is it that the climate is not getting warmer, or it might be but we don't know if it is or it isn't, or it is getting warmer but it is all due to non-human causes, or it is getting warmer but it might be due in part to human causes but we don't know, or it is getting warmer but it is beneficial? And all the views I just listed you think are wrong, do you believe the people who hold them are irrational, and do you argue against them?

Or is it that you don't care what people think and why, as long as they are opposed to governmental actions like reducing carbon emissions and promoting renewables?

Re: Some of the World's Biggest Lakes Are Drying Up

#15

Post by verelo » Sun, Mar 04, 2018, 2:31 AM UTC

I have to admit i know nothing about this, so i want to ask what feels like a dumb question: What stops water from evaporating into space? I feel like the answer is something simple like "gravity", or "condensation", but we seem to think Mars once had water, so where is it now, and will that happen here too?

Re: Some of the World's Biggest Lakes Are Drying Up

#16

Post by cstejerean » Sun, Mar 04, 2018, 2:35 AM UTC

verelo wrote: post #15

I have to admit i know nothing about this, so i want to ask what feels like a dumb question: What stops water from evaporating into space? I feel like the answer is something simple like "gravity", or "condensation", but we seem to think Mars once had water, so where is it now, and will that happen here too?

Gravity and a magnetic field. Gravity keeps the atmosphere from floating away, and the magnetic field protects it from getting stripped by solar radiation. The problem on mars is he magnetic field.

Re: Some of the World's Biggest Lakes Are Drying Up

#17

Post by libertine » Sun, Mar 04, 2018, 2:35 AM UTC

narag wrote: post #13

libertine wrote: post #3

You don't need to go to South America, Asia or middle East - it's happening in Europe and no one seems to notice. Look at Portugal and Spain, it's becoming a desert - the day of the cold wave the south of Portugal and Spain had the same temperatures of some country's in Africa.

Spain mainland is separated from Africa by a mere 14 km strait, so no wonder temperature is similar, not talking about Canary Islands that are like a thousand km further to the south. Southwest mainland is becoming a desert indeed, but that's nothing new. Most classic spagetti westerns were filmed there. It's Sahara crossing the sea and a good thing for "plastic sea" (greenhouses). Almería provides several vegetables…

Uh, neither Spain or Portugal has ever had the same climate has the north of Africa - not at least in the recorded history.

Here's an example of the 27th of February: http://images.meteociel.fr/im/8481/temp_eur2_crn3.png

Re: Some of the World's Biggest Lakes Are Drying Up

#18

Post by libertine » Sun, Mar 04, 2018, 2:38 AM UTC

thaumasiotes wrote: post #11

libertine wrote: post #3

You don't need to go to South America, Asia or middle East - it's happening in Europe and no one seems to notice. Look at Portugal and Spain, it's becoming a desert - the day of the cold wave the south of Portugal and Spain had the same temperatures of some country's in Africa.

> the south of Portugal and Spain had the same temperatures of some countries in Africa Tropical Africa, or are you saying the temperature in the south of Spain was comparable to the temperature in Morocco fourteen kilometers away?

I'm saying it had the same temperature (o was warmer even) then some parts of the north of Africa - not just Morocco: http://images.meteociel.fr/im/8481/temp_eur2_crn3.png

Re: Some of the World's Biggest Lakes Are Drying Up

#19

Post by cstejerean » Sun, Mar 04, 2018, 2:39 AM UTC

woodandsteel wrote: post #14

teslabox wrote: post #8

How much of the missing water is actually due to higher temperatures, and how much is due to people siphoning water from the aquifers that feed the lake? This article mostly focuses on "climate change" hysterics, but also acknowledges the siphoning problem. A HN comment [0] linked to a TucsonWeekly [1] piece about how Tucson used to be an oasis. Similarly, the Salt River used to run year-round through Phoenix. Las Ve…

>This article mostly focuses on "climate change" hysterics So what is your view on climate change? Is it that the climate is not getting warmer, or it might be but we don't know if it is or it isn't, or it is getting warmer but it is all due to non-human causes, or it is getting warmer but it might be due in part to human causes but we don't know, or it is getting warmer but it is beneficial? And all the views I just…

One can fully agree that climate change is an important issue that needs to be dealt with, yet still have a problem with it being waved around irresponsibly on unrelated issues.

Re: Some of the World's Biggest Lakes Are Drying Up

#20

Post by oldcynic » Sun, Mar 04, 2018, 2:42 AM UTC

verelo wrote: post #15

I have to admit i know nothing about this, so i want to ask what feels like a dumb question: What stops water from evaporating into space? I feel like the answer is something simple like "gravity", or "condensation", but we seem to think Mars once had water, so where is it now, and will that happen here too?

There are tiny losses from the upper atmosphere, but not enough to matter.

If you look at the water cycle[0], you'll see that as the water vapour rises it condenses - it gets quite cold a few miles up. Clouds consist of tiny droplets of liquid water and ice, not vapour.

[0] https://en.wikipedia.org/wiki/Water_cycle