Comments on: Distribution of Water on the Earth https://gregladen.com/blog/2009/08/04/this-has-come-up-a/ Thu, 06 Aug 2009 13:18:17 +0000 hourly 1 https://wordpress.org/?v=6.4.6 By: greg laden https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541035 Thu, 06 Aug 2009 13:18:17 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541035 Nathan: Well, that’s what I meant. If you look at those numbers, one has no a priori reason to question precision, but given what is being measured, seeing apparently significant digits as they are, one might suspect. But if we change to smaller units, and retained the same actual precision, you would see a lot of zeros on the right side and the perception that they are over-precise would vanish, yet the numbers are exactly the same (just different units).

]]> By: Nathan Myers https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541034 Thu, 06 Aug 2009 13:14:28 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541034 Greg: Measurement precision doesn’t change when you change units, it just moves the decimal point around.

]]> By: jj https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541033 Wed, 05 Aug 2009 13:21:46 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541033

Well, two percent isn’t much, but, unfortunately, the place it will be most obvious is in shallow water and lowlands

Glacial Ice melt is NOT major concern regarding sea level rise due to global warming. It’s the expansion of sea water volume at higher temps. Or at leased that’s what I’ve heard via lectures.

]]> By: Mark P https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541032 Wed, 05 Aug 2009 12:30:15 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541032 Well, two percent isn’t much, but, unfortunately, the place it will be most obvious is in shallow water and lowlands. Where we like to live.

]]> By: Nathan Myers https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541031 Wed, 05 Aug 2009 11:59:53 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541031 If people wouldn’t strip off error bars, they wouldn’t have to keep answering questions like this.

]]> By: Greg Laden https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541030 Wed, 05 Aug 2009 08:43:13 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541030 Nathan: As far as swamps and groundwater go, there is, of course a whole science dedicated to that and although it is harder to measure, I’m sure we essentially “know it” even if we (well, actually, you) don’t know how other people measure it!

As to the precision, there is no particular reason why we don’t have the precision indicated here, but I’ve not assessed that or made adjustments in these numbers. But do remember that significant digits is a buggaboo (sp?) If the measurements were made in cubic miles, the precision would go up with the same signficant digits. If the measurements were made in cubic centimeters the precision would go down. This is cubic kilometers. Cubic kilometers seemed like the right unit to use, but they are kind of small for planetary geology, so I would take the precision on the fresh water values with a grain of salt.

But only a grain, or it will become salt water.

If you go to the USGS source, there will be a reference to the source, where the method of estimating is probably given.

]]> By: jimspice https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541029 Wed, 05 Aug 2009 00:02:04 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541029 So if you juiced every living thing on earth, you would have a cube 10.4 K on a side? But there would be no one left to measure it?

]]> By: Nathan Myers https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541028 Tue, 04 Aug 2009 23:57:40 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541028 Incidentally, I’m astonished at the precision. Do we really know the oceans’ volume to ten significant figures? I’m almost equally impressed at knowing swamps’ volume to five figures. Who knows what’s under there?

]]> By: Nathan Myers https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541027 Tue, 04 Aug 2009 23:08:37 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541027 Of course nobody has even a faint idea what the cloud cover will do at the higher temperatures and C02 levels. We might end up in a global ice age after all, despite all. The global thermonuclear war likely to occur once the ice age starts might fend it off, or accelerate it. The survivors won’t even know if it did, either way.

]]> By: Greg Laden https://gregladen.com/blog/2009/08/04/this-has-come-up-a/#comment-541026 Tue, 04 Aug 2009 22:58:19 +0000 http://scienceblogs.com/gregladen/2009/08/04/this-has-come-up-a/#comment-541026 A total meltdown of the glacial ice would increase the amount of water in the oceans by about 2 percent. (But there are complications)

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