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Genuine question here. What would be the expected change over the same period? The abstract says 53% of lakes saw declines...does that mean 47% saw no change or
by ooz16 3y ago
Genuine question here. What would be the expected change over the same period? The abstract says 53% of lakes saw declines...does that mean 47% saw no change or gains? If so, that seems pretty close to net stable to me globally. Or frankly what we would expect to see (some gains, some losses)
Also, this is stated later in the doc:
"Between 1984 and 2015, a loss of 90,000 km2 of permanent water area was observed by satellites—an area equivalent to the surface of Lake Superior, whereas 184,000 km2 of new water bodies, primarily reservoirs, were formed elsewhere (14)"
My first impression was that this means there has been a growth in total permanent water area from 1984-2015. Am I just reading this wrong?
- abracadaniel 3y agoThat sounds reasonable. The water would have to go somewhere, but that alone could be catastrophic regionally. Cities are built around water sources, so having them move on timescales of human lifespans is worth worrying about.
- goatlover 3y agoTrue, but we're rather capable of building long pipelines to ship liquids across large distances.
- MattGaiser 3y agoIt would require a lot of expansion for the required volume. A barrel of oil has about 159 litres in it. The Keystone Pipeline would have transported 1.1 million barrels if it were fully expanded. 174,900,000 million litres per day. The City of Phoenix by itself uses about 1 billion litres per day.
- adhesive_wombat 3y agoI was going to say "but that probably double-counts recycled water" and then I looked it up and recycled water is only 8% of Phoenix's water usage, and it's 10% nationally in the US.
- _3u10 3y agoWater isn’t toxic though, aqueducts aren’t built to anywhere near the standards of oil pipelines.
- q1w2 3y agoMost people live by the ocean or on major lakes and rivers. This data doesn't show any of that changing.
- explaininjs 3y agoThe article also states “climate change and human activities increasingly threaten lakes that store 87% of Earth’s liquid surface fresh water”, but neglects to mention that only 0.3% of freshwater is liquid surface water in the first place. All in all a giant nothing burger, as with so many climate change alarmist “science” nowadays. https://www.usgs.gov/special-topics/water-science-school/science/freshwater-lakes-and-rivers-and-water-cycle#overview https://www.usgs.gov/special-topics/water-science-school/sci...
- wittenbunk 3y agoBecause obviously the amount of surface water is completely independent of the amount of subsurface water in aquifers. /s
- explaininjs 3y agoWhat do you think the “obvious” correlation coefficient is between the two? Or even its sign? I suppose it’d be far too much to ask for the R value too. Science is supposed to answer these questions, instead this article carefully withholds information to make molehills into mountains.
- MattGaiser 3y ago> but neglects to mention that only 0.3% of freshwater is liquid surface water in the first place. But what percentage of the water we can actually use? The Arctic and Antarctic are far away from most of us, and groundwater is limited and probably spread out quite a bit. Water vapour is hard to extract from the air. You are trivializing it by saying it is just a tiny percentage of freshwater, but it is actually where most of our used water currently comes from.
- explaininjs 3y ago> But what percentage of the water we can actually use? What percentage of lake water could we use prior to literal millennia of engineering effort was put into moving it where we need? > most of our used water currently comes from This is technically true today, but barely. Nationwide roughly twice as much water comes from surface as the ground, but it varies dramatically by region. If you live in NY, 90% of your water already comes from the ground. It’s certainly not the case that we’re “locked in” to lakes, rather we are very capable of adapting to local conditions.
- deleted 3y ago[deleted]
- LesZedCB 3y ago> Globally, natural lake volume declined at a net rate of −26.38 ± 1.59 Gt year the phrase you read said "Over half (53 ± 2%) of the large lakes experienced significant water losses" (emphasis mine)
- onlyrealcuzzo 3y agoIs 26.38 Gt a lot? There's 91k cubic kilometers of fresh water in lakes according to: https://www.usgs.gov/special-topics/water-science-school/science/how-much-water-there-earth https://www.usgs.gov/special-topics/water-science-school/sci... And a cubic kilometer is basically a Gt, right? .98 Gt? So 26 / 91,000 = ~0.02% ? Is that a lot? If it's really 0.02% - wouldn't you expect something to be random noise? How do we know it's not random noise?
- time_to_smile 3y ago[flagged]
- PM_me_your_math 3y agoSo we should have 100% faith in what we're being told in the article? If the author was trying to deceive then they wouldn't cite data that provided contradiction. Seems more like a religious approach than a logical one. There are papers, that were well cited, claiming there would be no sea ice by 2010, which never occurred.
- roqi 3y ago> So we should have 100% faith in what we're being told in the article? If you're asking questions that are answered in the article then that means you're discussing things without any context or insight or understanding, and have no intention to gather that context or insight or understanding. You aren't asking questions in good faith if you purposely avoid the answers.
- lovemenot 3y ago
- throwaway290 3y agoit sounds like new water bodies are man-made reservoirs, not permanent, e.g. the thing goes out into the ocean when the dam breaks.
- neves 3y agoI just think that if it was the case, Science Magazine would have changed the headline.