The reason I, or anyone else for that matter, might be interested in what he (or a non-climatologist) has to say is an attempt at avoiding any hoopla stemming from scientists trying to earn a paycheck. Global climatology is no where near the black and white science that cardiology or electrical engineering is.
It is not the province of people who start using blatantly inflammatory language such as fraud, activist, Scare-with-a-capital-S right out of the gate. That is the province of knee-jerk ideologues and cranks.
The main thing people who approach the subject in such a manner have to teach us about the science, is why refereed discussion has become such an integral part of the scientific process.
He also doesn't note that, if we end up with "sea levels hundreds of feet higher and in general, GREEN from pole to pole" that a significant number of the world's cities would need to be moved or surrounded by monumental dikes because of the ~200' rise in sea level that would accompany the melting of the Antarctic and Greenland ice shelves. BILLIONS of people would be displaced.
Oh, and he ignores the sea becoming more acidic, causing the likely extinction of most higher sea life as the food chain collapses. Corals are already on the brink worldwide. At least there will still be jellyfish.
Given that 75% (to a first approximation) of the surface of the planet is ocean, and that ice that is currently in the ocean is already displacing its mass (so not contributory to sea level rise when it melts), lets do a little math.
Using a nominal radius of 4,000 miles for the planet (yes its an ellipsoid I know), and only 75% of the surface area is water, we can compute the surface area of the ocean (approximately) as
(4/3*pi*4000^3) * .75 = 201,056,640,000 sq miles.
Call is 200 billion square miles. And we can convert 200' of sea level rise into miles by using 200 ft / 5280 ft/mi to get .0378 miles. So the volume of water that would have to flow into the ocean is then: 201,056,640,000 * .0378 = 7,599,940,992 miles^3 of water
We know ice is 92% the density of water, so its going to take up 8.7% more volume so 7.6x10^9 miles^3 * 1.0869 is a bit more than 8.25 billion cubic miles of ice.Now Wolfram Alpha [2] puts the area of the North American Continent at 9.461 million mi^2, so this ice we're melting, if it were on the north American continent, would cover it to a depth of 8.25 billion / 9.461 million, yes 873 miles. Way out into orbit. I've looked around on Google Earth and can find no ice structures which poke out of the atmosphere :-).
But there is an even simpler way to 'check the facts' here. For every foot of sea level rise, we need to melt 1.0869' * (.75/.25) = 3.4' of ice over all of the land in the world. That doesn't sound too bad until you try to figure out how much of the existing land today supports 100% ice holding (which is to say, water which is, but for temperature, permanently locked into ice so glaciers and the poles and the peaks over 12,000') That number is closer to 1% of the total land mass, and that is only .25% of the earths surface area, yes 300' thick ice in those areas for each foot of sea level rise.
Bottom line, given what we know of the ice on our planet, if we melt all of it, we'll be lucky to get 20' of sea rise. 200' is completely out of the question unless a comet hits us that is 100 miles in diameter, at which point all bets are off.
[1] http://www.wolframalpha.com/input/?i=area+of+USA
[2] http://www.wolframalpha.com/input/?i=area+of+north+america
"He also doesn't note that, if we end up with "sea levels hundreds of feet higher and in general, GREEN from pole to pole" that a significant number of the world's cities would need to be moved or surrounded by monumental dikes because of the ~200' rise in sea level that would accompany the melting of the Antarctic and Greenland ice shelves."
I saw the '~200'' to mean 'on the order of 200 feet'. I've also heard the 200' number mentioned elsewhere [1][2] and it is complete fiction, there isn't enough water on the planet locked up in ice to raise the oceans 200', if there was we could see it by the way it protruded out of the atmosphere.
And sure if Manhattan flooded and we lost most or all of NY City that would be a huge hit to the country, and if we lost all of Bangledesh (estimates of 3M people living at 3' sea level) that would put a huge crimp on the rest of the India to absorb all those refuges and compensate for the lost arable land. Epic human tragedy.
My contribution here is simply a mathematical analysis of the more absurd numbers people use because humans have a hard time internalizing very large numbers (like 200 billion square miles of ocean surface).
[1] "What is very clear, however, is the importance of Antarctica's huge ice sheets remaining stable. The West Antarctic ice sheet is thought to be potentially unstable, and if it collapsed sea levels around the world would rise almost 20 feet. The melting of the larger and more stable East Antarctic ice sheet would raise Earth's sea levels another 200 feet." - http://www.sciencedaily.com/releases/2002/03/020329072043.ht...
[2] " If all of the Antarctic ice melted, sea levels around the world would rise about 61 meters (200 feet). But the average temperature in Antarctica is -37°C, so the ice there is in no danger of melting. In fact in most parts of the continent it never gets above freezing." - http://science.howstuffworks.com/environmental/earth/geophys...
6000000/200000000000 = .00003
That means that for every foot of ice melted from these two areas combined, you could expect an average sea level rise of .00003 feet (or 360 millionths of an inch). So lets say you melted 10,000' of ice off that combined land mass, that would be, wait for it, an average rise of 3.6".They are just numbers, but they put things in perspective.
Oops. Looks like you're off by a factor of 1000, since Wolfram is saying the total is 131.6m sq. miles (487k sq. km). [1] But what's three orders of magnitude among friends...
The Antarctic Ross ice shelf is about 188k sq. miles, and up to 750m thick. Again according to Wolfram Alpha, that makes 3.653×10^17 L (liters) of ice. 92% of that is 3.36×10^17 L (liters).
And if you spread that many liters over the (Wolfram Alpha) area of the the oceans, you get nearly a meter sea level rise (0.9856). That's one (albeit large) shelf.
The Greenland ice sheet comes to almost 4.27×10^18 L (liters) of ice (based on numbers from Wikipedia and an average thickness of 2.5km) [2]. We're up another factor of 10 here, with 12.530 meters of rise now.
According to WikiPedia, the Antarctic Ice Sheet contains 30m cubic km of ice, and they claim it's worth 70m of ocean depth. [3]
But let's crunch some numbers. If you assume 92% density you get 2.76×10^7 km^3. Again in Alpha I get 80.96m [4], or 265'. The truth is that, as the sea level rises, the SURFACE AREA will change (because so much land will be flooded), and so even though the combined rise of all ice melting might be 300' at the current area of the oceans, the estimates are that it would only rise about 200', plus or minus.
So how do the numbers not agree with me? THIS is why it's useless to take an engineer's view of something like climate change. Misplace a decimal point (or cube when you really mean 4pi r squared) and suddenly you're making all kinds of crazy assumptions. And yes, I forgot the surface area of a sphere too, but the more serious error is assuming your rusty memory of a math equation can prove that ALL THE EXPERTS are wrong and you're smarter than they are.
[1] http://www.wolframalpha.com/input/?i=area+of+all+oceans&... [2] http://en.wikipedia.org/wiki/Greenland_ice_sheet [3] http://en.wikipedia.org/wiki/Antarctic_Ice_Sheet [4] http://www.wolframalpha.com/input/?i=%2830+million+cubic+km+...
So the volume vs surface area, doh! 4-pi-r^2 does change the rough calculation from 200 billion to 151 million. Cool.
So a 200' rise is only 5.7M cubic miles of water, or 6.2 cubic miles of ice. Or a North American ice sheet that is only 2/3rds of a mile thick (about 3500'). Well that is better, for the nominal 6M square mile greenland/antarctica region its basically needs to be a mile thick.
Ok so that is an interesting correction to my numbers, now lets look at yours.
"The Antarctic Ross ice shelf is about 188k sq. miles, and up to 750m thick. Again according to Wolfram Alpha, that makes 3.653×10^17 L (liters) of ice. 92% of that is 3.36×10^17 L (liters)."
Ok, how much of the shelf is already in the ocean and how much is supported by the antarctic continent? (the reasoning being that melting ice that is displacing an equivalent volume of water results in no net change in water level).
We can make that a factor in the numbers or not. Using it as a variable, 188 thousand square miles 750m (.466 miles) thick is 87,608 cubic miles, spread across our 151M square miles of ocean its .0058 miles of rise or 3' or nearly 1 meter.
Nice I like being able to come at the numbers both ways and have them agree.
"So how do the numbers not agree with me? THIS is why it's useless to take an engineer's view of something like climate change. "
No need to be snippy, I appreciate the corrections, the base issue was the volume vs area starting formulation. It is never "useless" to corroborate claims by starting from some known facts and doing the math on them. Many outrageous claims fly by all the time. It also helps ground the conversation in a testable way.
I misspoke when I mentioned the ice shelf. That part IS at least partly floating, and therefore already displaces as much sea water as its mass can account for. I thought it wasn't, but I was wrong. BUT...the other numbers still stand.