Speaking of higher seawalls…
The Netherlands protects a huge amount of land below sea level. Can those dykes be raised another meter or two? What is the cost or feasibility of protecting other endangered areas with seawalls, e.g. Bangkok and Central Thailand? (I suppose Central California could be protected with relative ease by damming the Carquinez Straits, no?)
How long did it take to replace the levees around New Orleans?
I’m glad I live on high ground - such as it is - given that the downtown already goes underwater during some high tides. Some of that is due to our recent unpleasantness, but the rest is your regular tide action.
Charleston makes a wonderful bulls-eye for category 5 hurricanes, you should be ready for ten foot sea-level rise on a week’s notice. If not, then melting ice and thermal expansion are the least of your worries …
The sea ice off Antarctica is increasing…in both area and depth. Explanations for this (by the AGW crowd) include the idea that melting continental ice has diluted the sea water, to the point that the freezing point (of the seawater) has increased-calculations for this do not support this.
That’s wrong for a number of reasons. Temperature changes vary greatly across different ocean regions, vary greatly with depth, and the coefficient of expansion varies significantly with ocean depth. Moreover, climate model calculations are always based on the coefficient of volumetric expansion of seawater at different depths (because we’re concerned about the increase in volume resulting from decrease in density), reasonable approximations being ε[sub]T[/sub] =2.7×10[sup]-4[/sup]°C[sup]-1[/sup] for the upper ocean and ε[sub]T[/sub] = 1.5×10[sup]-4[/sup]°C[sup]-1[/sup] for the deep ocean.
So a first approximation that’s actually used in climate models for change in sea level δh for any given depth h and temperature change δT is:
δh = h ε[sub]T[/sub] δT
This works out to about 0.45 m ºC[sup]-1[/sup] in your hypothetical example using the deep ocean coefficient alone, probably more like half a meter if computed more accurately.
That’s why thermal expansion has been responsible for roughly half of sea level rise until recently, though contribution from ice melt is now overtaking it.
I was going to say Norfolk, Virginia has it worse, but looking at the pics, maybe not. I think I posted this somewhere before:
https://www.washingtonpost.com/business/economy/in-norfolk-evidence-of-climate-change-is-in-the-streets-at-high-tide/2014/05/31/fe3ae860-e71f-11e3-8f90-73e071f3d637_story.html
Indeed, and incidentally recently was a report that mentioned that there is an increase of ice inland, in Antarctica, suffice to say even the author of the study knew ahead of time that deniers were going to grab it and run with it, ignoring that his study also reports that the increase does not contradict what has been observed elsewhere in West Antarctica and in the northern hemisphere. Basically almost all researchers agree that the gains observed in some areas in the Antarctic can not overcome the huge loses observed elsewhere.
It never ceases to amaze me how utterly unprincipled these denialists are in pursuing their mercenary goals. Monckton is a complete crackpot who thinks AGW is a socialist conspiracy to set up a socialist world government (he also thinks anyone with AIDS should be immediately and permanently quarantined in some kind of AIDS concentration camp and permanently removed from society). Denialist groups like the Heartland Foundation and SPPI bill him as a “climate scientist” and expert adviser whereas he has no scientific credentials at all – zero. The UK House of Lords has had to take the unprecedented step of publicly denying that he is a member.
But some might wonder who the gentleman is who is so enthusiastically interviewing him and fawning all over him in that video. He might not be very recognizable outside of Canada, but that is Ezra Levant. Levant is a climate change denialist, and his resume pretty much fits the denialist to a tee. He is a former far-right political activist turned frothing-at-the-mouth self-promoting blowhard. He was formerly a paid shill for the tobacco industry, turned paid shill for the oil industry. He’s been sued for slander and defamation by no fewer than six prominent individuals, and he lost five of them while one is still before the courts, and had to make settlements and apologize for malicious lying in all of them.
He’s been disciplined three times by the Canadian Broadcast Standards Council and by the Alberta Law Association for ethics violations. He was the major draw of a slimy, disreputable new TV station that was an attempt by far right nutjobs to establish a kind of Canadian version of Fox News. Turned out there was no market for that in Canada, so as a last resort they appealed to the CRTC (the Canadian version of the FCC) for must-carry status on cable, arguing they were a “news channel” on a par with CBC Newsworld. When the CRTC was done laughing they told them to go pound sand. So they shut down and Ezra and his pals are now making YouTube videos like that one with Monckton. They appreciate each other because they both so much enjoy lying to the public.
And that’s a typical story of another climate denialist.
I used linear expansion because the ocean margins are quite literally set in stone, the oceans have no place to expand but in the vertical. Both methods will give the same results, just I’ve saved myself from having to divide volume by surface area.
From what you posted, it looks like expansion is less at higher pressure, plus heat energy from the surface takes a long time to conduct down to depth (as convection is inhibited by the temperature inversion). Could you go ahead an post your math or give a link where the calculations are shown?
<nitpick>Typically when one posts an equation, like δh = h ε[sub]T[/sub] δT, each symbol is clearly defined and units specified.</nitpick>
Obviously they don’t yield the same results, since your results are wrong and off by more than a factor of 2. It’s not completely true that the oceans can expand only in the vertical, but it’s very nearly true. You’re contradicting your own argument. Think about it.
No online link, it’s from this text on climate modeling. But the only thing that you could reasonably challenge is the expansion coefficients, and Wikipedia gives the volumetric coefficient of expansion of pure water at 20°C as 207×10[sup]-6[/sup] °C[sup]-1[/sup]. My source gives an approximation of 2.7×10[sup]-4[/sup] °C[sup]-1[/sup] to use for modeling upper-level seawater expansion at 22°C, so the numbers are certainly in the same ballpark. I should mention that the deep-ocean coefficient is premised on typical deep-ocean conditions, namely a temperature of 2°C and pressure of 300 bar – it’s supposed to be comparable to the upper levels under real physical conditions and not for illustrative purposes of only pressure differences.
I clearly defined them. h is depth (meters was implicit, sorry if that wasn’t clear but I thought it was obvious), T is temperature in °C, ε[sub]T[/sub] is the appropriate coefficient of expansion at the depth in question, and δ in front of anything means the delta thereof. What’s the mystery?
Yeah, I clicked on that video and immediately reacted with “eww, you made me watch Ezra Levant. Get it off, get it off!”
What if it actually happens, and we were wrong. What if we pour all this money and genius into finding abundant (cheap) green, renewable energy, and we do it! And then we find out we didn’t really have to, we were wrong, global warming is an illusion and things will go back to normal anyway.
And we are stuck with all this cheap green energy! Wow, what a disaster!
I, for one, stand ready! “Sorry, guys, we dirty fucking hippies stuck you with this major advance in civilization. My bad!”
So how do we stand on the James Hansen non-linear-ice-melt-flood-everything-before-we’re-ready thing ?
Renaissance ain’t what it used to be.
Hansen came with very worrisome study, but many other researchers still consider that the rise of the oceans will take more time, still the biggest change regarding the most likely outcomes was to expect a 1 to 2 meter rise of th oceans by 2100, now the issue is that because of the acceleration of cap ice loss those numbers are bound to increase, and I have seen reports of that 1 to 2 meter increase to come by mid century in 2050.
The point is that while many are critical of Hansen the issue here is that his research can not be dismissed so easily, more research is needed, but as it was pointed many times in the past the contrarians and deniers in power still tell us that no such thing will take place. Not even the conservative estimates.
IMHO Hansen may be overstating the rate of ice cap loss, but if many only listen to the deniers chances are that we will not be ready indeed.
If the ice collapse accelerates there is a likely curve ball:
I expect by then that the deniers will claim that no scientist or model predicted that. While the climate in the northern hemisphere will be affected the oceans will continue to rise:
https://screen.yahoo.com/medieval-barber-000000006.html
[QUOTE=Theodoric of York]
"Wait a minute. Perhaps she’s right. Perhaps I’ve been wrong to blindly follow the medical traditions and superstitions of past centuries.
Maybe we barbers should test these assumptions analytically, through experimentation and a “scientific method”.
Maybe this scientific method could be extended to other fields of learning: the natural sciences, art, architecture, navigation.
Perhaps I could lead the way to a new age, an age of rebirth, a Renaissance!..
Naaaaaahhh!!"
[/QUOTE]
And then he joined the Tea Party…
Aren’t we pushing a rope at this point? Are there any underfunded technologies that could lead to cheap renewable power because ISTM that they are all getting money thrown at them as fast as they can rationally spend it.
That be a problem. UKIP (right wing party) got 16% of the UK vote this year and they want to eliminate climate change from the school curriculum.
Good point, but it seems that the focus is on punishing existing industry, and not on acknowledging/encouraging free market solutions. Doesn’t fit the political narrative…