Climate Change

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RoadScholar
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Re: Climate Change

#376

Post by RoadScholar » Thu May 17, 2018 10:48 pm

What a turkey. If things worked that way, by now there’d be no mountains left.

Uplift, dude. Tectonics. That’s why there’s stuff to erode. :brickwallsmall:


The bitterest truth is healthier than the sweetest lie.
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Tiredretiredlawyer
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Re: Climate Change

#377

Post by Tiredretiredlawyer » Fri May 18, 2018 8:34 am

Gneissly done your own self!! :thumbs:


"The people must know before they can act, and there is no educator to compare with the press." - Ida B. Wells-Barnett, journalist, newspaper editor, suffragist, feminist and founder with others of NAACP.

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vic
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Re: Climate Change

#378

Post by vic » Fri May 18, 2018 4:49 pm

I forgot to post this yesterday:

https://www.washingtonpost.com/news/pol ... 4968f377f9

It might not be scientifically rigorous, but it seems to be a nice first-order approximation. And since I majored in (but didn't complete a degree in) Physics, that's all that matters, right?
Here’s how big a rock you’d have to drop into the ocean to see the rise in sea level happening now
:snippity:
So to make the oceans rise 3.3 millimeters, we would need to displace that 1.2 trillion cubic meters of water upward by dropping in 1.2 trillion cubic meters of dirt or stone or whatever.

How much is that? It’s a sphere of earth a bit over 8 miles in diameter. If we were to balance it at the top of the Capitol building, it would look like this.
Image
If the sphere were stone, it would weigh about 6.6 quadrillion pounds. Just drop that in the ocean and — bloop! — 3.3 millimeters of sea-level increase. (We’re ignoring here that dropping it in some parts of the ocean would result in a mountain in that location. For the sake of explaining things, we’re pretending that the oceans are just one big uniform pool of water and that the sea level rise is similarly consistent. This isn’t how it works, of course.)

Put another way, it’s a volume of earth equivalent to taking the top five inches of every one of the United States’ 9.1 million square miles of land area and using it to coat the bottom of the world’s oceans. That would push sea levels up by 3.3 millimeters.

But, remember: That sea level rise happens annually. So every year, we’d need to take the top five inches of the United States, roll it in a ball and drop it in the ocean to get the sort of sea level rise we’re currently seeing. Don’t worry, though; assuming that the depth of Earth’s crust is about 40 kilometers in the United States, it would take 309,000 years for us to get to the mantle.

Except, of course, that sea level rise is occurring at an increasing rate. If someone could check on the white cliffs of Dover for us, we’d appreciate it.



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TollandRCR
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Re: Climate Change

#379

Post by TollandRCR » Fri May 18, 2018 5:44 pm

The rocks do not exist to raise the sea level. The ice shelves certainly do. Glacier melt is nice and slow, and expansion due to warming of the oceans is leisurely. We can build buffers and walls that will keep coastal cities going for a while. Collapse of the Ross ice shelf will get NYC's attention very quickly. Note that Ross sits above the ocean. It is doing nothing now to raise the sea level. An ungodly percentage of humanity lives in areas that will experience disastrous sea level rise with business as usual.


“The truth is, we know so little about life, we don’t really know what the good news is and what the bad news is.” Kurt Vonnegut

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Jim
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Re: Climate Change

#380

Post by Jim » Fri May 25, 2018 2:43 pm

In a Warming West, the Rio Grande Is Drying Up

https://www.nytimes.com/interactive/201 ... rande.html

"But the state of the Rio Grande reflects a broader trend in the West, where warming temperatures are reducing snowpack and river flows.

A study last year of the Colorado River, which provides water to 40 million people and is far bigger than the Rio Grande, found that flows from 2000 to 2014 were nearly 20 percent below the 20th century average, with about a third of the reduction attributable to human-caused warming. The study suggested that if climate change continued unabated, human-induced warming could eventually reduce Colorado flows by at least an additional one-third this century.

“Both of these rivers are poster children for what climate change is doing to the Southwest,” said Jonathan T. Overpeck, dean of the School for Environment and Sustainability at the University of Michigan and an author of the Colorado study."



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