Today's Proceedings of the (US) National National Academy of Sciences includes a paper on the mass loss from the Antarctic ice sheet since 1979.
Our resident gullible denialists have told us that the Antarctic ices sheet hasn't been shrinking, which happens to be incorrect.
-- Bill Sloman, Sydney
So what ?. That on it's own doesn't say anything, nor prove cause. Climate change, maybe, or simple redistribution of heat around the earth?. One paper, or one swallow doth a spring not make etc .
Fact free "science" at it's best...
Chris
The cause is obvious enough - the average temperature of the planet is increasing, which has melted ice sheets often enough in the past (at the end of every ice age) to make cause an effect remarkably obvious.
We've got satellites scanning the planet - the surface temperature of the earth is rising. More in the Arctic than everywhere else, but I don't know of any place that is actually cooling, or even lagging that much.
It's not an isolated paper, as reading it would have revealed
You don't get to publish "fact free science" in the Proceedings of the (US) National National Academy of Sciences - it's a high prestige peer-reviewed journal.
There are eleven pages of extra facts here
You could have found them for yourself, if you had looked.
-- Bill Sloman, Sydney
Do we know the amount of snowfall all over Antarctis for the last few hundred years ? Any drop in snowfall with constant melting rate will cause a net loss of glacial ice.
We've got ice core data going back a lot longer than that. The thickness of successive layers of snow should tell us what you want to know.
There's absolutely no reason to expect the snowfall to have decreased, and as the southern ocean has warmed up with the rest of the planet over the last century or so there's every reason to expect that the snowfall has gone up a bit in recent years.
-- Bill Sloman, Sydney
Unfortunately ice core data can be quite inaccurate. Contrary to common beliefs, there can be quite warm air during the summer, not to mention the 24 h intense solar radiation. This will melt surface ice some years even multiyear snowfall. The melting ice forms ice lakes. Sooner or later, the water drops through the ice to ground through crevasses, thus one or more years of snowfall is lost. Alternatively the ice lake will freeze in the fall forming a single new layer, possible loosing multiple years of data.
So no direct evidence.
None of this is relevant to research results; the data can be accurate, and is cross-checkable at multiple sites. There's tree-ring data hard to read during the 'year without a summer', but we can think our way past those things.
"Common beliefs" aren't what scientists come up with.
That's not right. It's not even wrong. The day before the first nuclear explosion, there was no direct evidence it would happen, but the calculations were accurate.
Hard-working fools can see indirect evidence, only lazy ones need it direct.
A reminder: a thermometer isn't 'direct evidence' of temperature: volume changes of glass and mercury are the reason for the reading. But, putting your finger into the candy kettle is not recommended: be indirect, use the thermometer.
es includes a paper on the mass loss from the Antarctic ice sheet since 197
es sheet hasn't been shrinking, which happens to be incorrect.
of successive layers of snow should tell us what you want to know.
So where is your link to the particular ice core that exhibits this behavio ur?
shows an 800,000 year ice core from what must have been a more favoured loc ation.
nd as the southern ocean has warmed up with the rest of the planet over the last century or so there's every reason to expect that the snowfall has go ne up a bit in recent years.
see figure 1 in
It looks pretty direct to me. Not for the snowfall - which isn't all that i nteresting - but if they can get CO2 levels out, the thickness of the annua l layers should be a doddle. I did have contact in the Scott Polar Antarcti c Research Centre in Cambridge UK, but he died at the end of last year.
-- Bill Sloman, Sydney
the politically important questions are
what should we do about it?
is there not any other solution besides a new tax on carbon?
mark
On the Northern hemisphere, continuous reliable tree ring series are available for 7000-8000 years accurate to few months, much more reliable than any ice core or C14 timing.
But for Antarctica, where do you get tree rings :-).
OK, you might find some fossil tree rings in coal, but these are several million years old and affected by continental drift.
Yep, agreed.
Well, no, that's not important. The way to make a decision, is to examine both costs and benefits of a multiplicity of paths, and NOT to pick a path with large cost and low benefit. Taxation isn't a clear cost (it enriches a nonprofit entity) nor benefit, it's just a connecting link.
The Antarctic ice sheet goes back about 45 million years, and any tree rings in coal are going to be older than that, from when the Antarctic continental plate hadn't yet got to the South Pole.
You really haven't been paying attention.
-- Bill Sloman, Sydney
e:
ne both costs and benefits of a multiplicity of paths, and NOT to pick a pa th with large cost and low benefit. Taxation isn't a clear cost (it enric hes a nonprofit entity) nor benefit, it's just a connecting link.
The path that does seem to be working at the moment would seem to be making solar cells in large enough volume to let them undercut power generation b y burning fossil carbon.
In Australia, the power companies aren't investing in new fossil carbon fue lled power generating plants, and are investing in solar farms - they can g enerate power more cheaply that way.
At present the planet gets 1% of it's electricity from solar cells. If we a re to up the proportion to 10%, we'll have up the volume manufactured by an other factor of ten which will probably halve the unit cost of the solar ce lls again.
Germany spent the money to scale up manufacturing by a factor of ten about twenty years ago, and did halve the unit price in the process, and China pu lled the same trick a few years back, and halved the unit price again.
The next step will need an even bigger capital investment, but it is very l ikely to pay off on a large scale.
The utility companies will have to start investing in pumped and battery st orage, but getting the electricity they sell for half the price they are pa ying now will pay for a lot of storage.
-- Bill Sloman, Sydney
really? what happens?
24 hour twiglight more like.-- When I tried casting out nines I made a hash of it.
There are other solutions, (eg: kill lots of people, ban coal and oil...) The tax is the least bad.
-- When I tried casting out nines I made a hash of it.
No problem with pumped and we already have that in the uk, but we have limited number of places where it can be used. Battery storage is a complete non starter though, Quite apart from the environmental impact during manufacture and disposal, they usually have a design life of ~5 years under cycled conditions. Not only that, but the shear volume and weight of a bettery set to equal the output of say, a single 1 Gw fosil fuelled power station is also impractical. You do the sums based on a 12v 100Ah battery, 1200 watts hours at the
10 hour rate and it becomes obvious. Had this discussion > once on the Guardian pages in the past.Problem is that hydrocarbon is a very concentrated source of energy and only nuclear has been able to match that so far. It's a very difficult problem to fix with no easy answers...
Chris
It's a gift, not a problem.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Absolutely, but it will run out at some stage so we should ramp up efforts to find valid substitutes, rather than the fools gold of solar and wind. Sure, they make a contribution, but won't be a long term cost effective solution. As for the noble cause of saving the planet, that whole business is so controversial and beset by big money, trillions of $ carbon credit trading etc, doubt if we will ever know the real truth. Money and politics corrupts everything it touches...
Chris
y storage...
Pumped water is easy, but does depend on having lakes and hills. Pumped air doesn't depend on local topography to anything like the same extent.
A strange claim, when it has already started and is doing rather well.
, they usually have a design life of ~5 years under cycled conditions.
Probably not true any longer.
Vanadium redox batteries don't seem to have all that much commercial exposu re yet, but there are enough big proof-of-principle examples around to sugg est that they are going to fill that particular hole in the incipient marke t, if the batteries in parked electric cars don't do it first.
the output of say, a single 1 Gw fossil fuelled power station is also impra ctical.
Rubbish. The 100 MegaWatt Tesla battery in South Australia may be massive, but the photo of the site in the link I posted makes it obvious that accomm odating nine more of them wouldn't be difficult.
Amongst other things, it is clearly a single-storey structure, and stacking the modules three deep wouldn't involved any fancy structural engineering.
Lead-acid batteries aren't the technology of choice.
Rubbish. What's good about having a concentrated source of energy when the energy consumers are spread across the landscape?
At the moment half my power bill goes on paying for the poles and wires tha t get my electricity from some giant out of town generating plant to my apa rtment close to the centre of Sydney. Most of the cost is probably paying f or the poles and wires that service rural New South Wales, and the solar fa rms that are growing like mushrooms in the drier (and less fertile) rural a reas will take load off that rural part of the network.
There's also plenty of room for mains battery back-up out there.
-- Bill Sloman, Sydney
Cruachan plus Dinorwig have 16GWh storage. How much use is that? Today's power varied between 30GW and 45GW. So not much; the arithmetic isn't tricky!
They are generally useful only for smoothing out consumption peaks and unplanned mainstream outages.
Amd, of course, one is kept in reserve in case a "blackstart" is needed.
Exactly.
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