Climate Change

[Quartz]

Did you pull that out your arse?

No, I did the calculation. Figures are available from Wikipedia and elsewhere. Even the worst melt figure of 239 cu. km per year works out at over 11K years. The more recent figure of 195 cu. km / year gives us over 14K years. Are you suggesting my calculation is incorrect? But you know what, even if I'm out by a factor of 10, to allow for the non-linear factor, and the Greenland ice sheet takes a mere 1000 years to melt, it's still well beyond the fossil fuel threshold.

Don't worry about all this maths stuff; stick to scaremongering.

 

[ferrelhadley]

No, I did the calculation.

So you did pull it out your arse.

Are you suggesting my calculation is incorrect?

Clearly you are too stupid to understand my last post.

it's still well beyond the fossil fuel threshold.

What are you gibbering about.

Don't worry about all this maths stuff;

You have done some primary school level arithmetic. How thick are you that you think you can boast about that. Ice sheet melt is observed to be sigmoidal.

Showing us all you can use times tables does not in any way invalidate the actual scientists making actual predictions.

Still chuckling at someone trying to patronise people because they can do their times tables.

 

[Quartz]

Ice sheet melt is observed to be sigmoidal.

I'm well aware of what sigmoidal means. But how many years of measurement of the Greenland ice sheet have there been? Not enough to make that judgement of the GIS. I'll also note your post-glacial sea rise chart shows next to no rise for the latter part of the Holocene Maximum, when it was as warm as it is now for an extended period.

Showing us all you can use times tables does not in any way invalidate the actual scientists making actual predictions.

Predictions. Lovely things, predictions; very convenient too, especially over long timescales. So they can't be proved or disproved.

Don't put me down as a Daily Mail-esque denier of global warming. It's plain as a pikestaff that it's happening. But reactions like yours do you poor service and put you firmly in the Chicken Little category.

 

[ferrelhadley]

I'm well aware of what sigmoidal means.

, even if I'm out by a factor of 10,

But how many years of measurement of the Greenland ice sheet have there been? Not enough to make that judgement of the GIS.

Do you believe a) the sea level has been rising about 30cm a century and no one has noticed or b) that the Greenland ice sheet has been melting but none of the water reaching the ocean.

I'll also note your post-glacial sea rise chart shows next to no rise for the latter part of the Holocene Maximum, when it was as warm as it is now for an extended period.

Predictions. Lovely things, predictions; very convenient too

It's losing ~200 cubic km per year (measurements vary) and there's 2,850,000 cubic km of ice. That works out at over 10,000 years.

Don't put me down as a Daily Mail-esque denier

No, you can do multiplication. That makes you a world expert on glaciers and ice sheets. Not a world expert, the world expert.

 

[Quartz]

Over to you then: how long will it take the Greenland Ice Sheet to melt?

 

[ferrelhadley]

Over to you then: how long will it take the Greenland Ice Sheet to melt?

I leave that for professional scientists studying the ice. I am not vain enough to imagine some arithmetic would make me such a person.

 

[Quartz]

So you refuse to state that my primary-school calculation is wrong, having denigrated it earlier? Put up or shut up.

Again, don't get me wrong: climate change is real. But idiotic posts like your attack on me do not help.

 

[ferrelhadley]

So you refuse to state that my primary-school calculation is wrong,

It is wrong.

 

[Quartz]

So give a figure.

 

[ferrelhadley]

So give a figure.

Bigger than yours.

As I have explained in easy to understand words, the ice sheets collapse is sigmoidal, (some of) the physical reasons for this have been laid out. Other reasons include that as the ice melts it drops in altitude, dropping altitude brings the ice surface to warmer air. c. 1C per 100meters. And ice sheets are warm at the surface due to accumulation of geothermal heat, so as water penetrates into the depths it can (i.e. has been seen too) remain liquid adding further lubrication deep within the ice sheet.

 

[Bob_the_lost]

From a brief google there is some contention on the matter. Some people stick to the linear calculations whilst others point out that there are significant non linear effects that can throw it all out of whack. A paper by James Hansen includes this line: "An ice sheet response time of centuries seems probable, and we cannot rule out large changes on decadal time-scales once wide-scale surface melt is underway."

Bluntly we don't know and I don't have the time or background to know which time frame is more accurate, centuries or millennia.

What is obvious is that no reputable scientists are putting a hard date on when all the ice might be gone by, as it's too hard to tell.

 

[free spirit]

Still chuckling at someone trying to patronise people because they can do their times tables.

worth pointing out that the IPCC figure was specifically for thermal expansion only, it did not include any contribution from ice melt because there was such wide disagreement at the time about the likely rate of ice melt, as the latest data was demonstrating rapidly increasing speeds of glacier flow / ice melt that confounded previous conservative assumptions.

Data since then has pretty much confirmed that the later more worrying results seem to be painting the most likely picture of what's going to happen.

eta - IIRC

 

[free spirit]

Over to you then: how long will it take the Greenland Ice Sheet to melt?

what level of temperature rise are you envisaging with this scenario?

If we're talking about 3-4 degrees rise by 2100, and probably at least another 3-4 after that due to thermal inertia alone, assuming that the current trend continues of the area around greenland and the north pole warming significantly more rapidly, then I'd estimate it at being largely ice free within low hundreds of years.

This isn't about the ice melting in situe as such, more about the sea ice breaking off, and increasing amounts of meltwater lubricating the base of the glaciers so they essentially float above the surface and slide off the mountains increasingly rapidly and out to sea to melt away.

Of course there is always the chance that it will melt so fast it will dilute the sea water to the point where it ends the north atlantic conveyor warm ocean current, at which point all bets would be off... that's what started the last European ice age (well, meltwater flooding in from the great lakes area from the melted North American ice shelf of the previous ice age).

 

[Bob_the_lost]

what level of temperature rise are you envisaging with this scenario?

If we're talking about 3-4 degrees rise by 2100, and probably at least another 3-4 after that due to thermal inertia alone, assuming that the current trend continues of the area around greenland and the north pole warming significantly more rapidly, then I'd estimate it at being largely ice free within low hundreds of years.

This isn't about the ice melting in situe as such, more about the sea ice breaking off, and increasing amounts of meltwater lubricating the base of the glaciers so they essentially float above the surface and slide off the mountains increasingly rapidly and out to sea to melt away.

Of course there is always the chance that it will melt so fast it will dilute the sea water to the point where it ends the north atlantic conveyor warm ocean current, at which point all bets would be off... that's what started the last European ice age (well, meltwater flooding in from the great lakes area from the melted North American ice shelf of the previous ice age).

Doesn't Greenland have mountains around the majority of it's coast lines, which would slow or stop a lot of the movement of intact Glaciers to the sea?

 

[ferrelhadley]

Doesn't Greenland have mountains around the majority of it's coast lines, which would slow or stop a lot of the movement of intact Glaciers to the sea?

This is why 'outlet glaciers' are so important. Glaciers like Jackobshavn, Petermann, Humboldt and the Russell glacier. This is where the ice is able to force itself between hills and into the sea. The ice sheet itself is 3km high at the top so acts like a 3km high blob of ultra viscous fluid. If you can imagine how water or mercury hold a shape because of the surface tension of a droplet*, well an ice sheet can hold a shape because it is so stiff it flows very slowly, but many features are only about 50 meters or less, so all that pressure from behind can push the ice over the hills and into the ocean. The problems are that the surface friction slows the rate of this flow. But the faster the glacier moves the more momentum it has behind it to over come the friction, the more surface melt penetrates deep into the glacier the more water that gets to the ground level and can lubricate the movement and as said up thread, the more than the sea ice buttresses collapse, as is happening to Petermann, the less friction is around to hold back a surge of movement.

The lowball estimate is 30cm per century from Greenland. No one really seems to know the high ball estimate. It may be a meter or more. We just have no real grip on what is happening in the Arctic ocean and how soon we will see that ice free for the 24 hour sun of June July. Also there is a fear of giant lakes of water building up deep inside the ice sheet and suddenly releasing pushing huge amounts of ice out with it. 20 years ago we modelled ice sheets as giant, static blobs of ice that took a thousand years to melt. Now we know they are very dynamic temperamental beasts who may have a few nasty tricks up their sleeve.

*It is not the same process but think of it as a way of imagining how a giant blob of ice with all that pressure can still hold itself back from just squirting into the ocean.

The WAIS on the other hand (the West Arctic Ice Sheet) (left side of this image)

Has few major geographic constraints, is often ground deep below sea level. It is showing deeply distrubing signs that its sea ice buttresses are "unzipping" all down the Antarctic Peninsula (the feature on the extreme left). The collapse of the Larsen B ice shelf for example and strong signs several other major buttressing ice shelfs are liable to go the same way over the coming couple of decades suggests that when the bigger ones go like Larsen C and the Wilkins Ice Shelf, the glacier flow from the Antarctic Peninsula could rapidly accelerate.

More over both the giant Pine Island and Thwaits Glaciers are thought to be approaching features that when crossed will see them accelerate.

A major Antarctic glacier may have passed its tipping point, according to a new modelling study. After losing increasing amounts of ice over the past decades, it is poised to collapse in a catastrophe that could raise global sea levels by 24 centimetres.

Pine Island glacier (PIG) is one of many at the fringes of the West Antarctic ice sheet. In 2004, satellite observations showed that it had started to thin, and that ice was flowing into the Amundsen Sea 25 per cent faster than it had 30 years before.

Now, the first study to model changes in an ice sheet in three dimensions shows that PIG has probably passed a critical "tipping point" and is irreversibly on track to lose 50 per cent of its ice in as little as 100 years, significantly raising global sea levels.

The team that carried out the study admits their model can represent only a simplified version of the physics that govern changes in glaciers, but say that if anything, the model is optimistic and PIG will disappear faster than it projects.

Richard Katz of the University of Oxford and colleagues developed the model to explore whether the retreat of the "grounding line" – the undersea junction at which a floating ice shelf becomes an ice sheet grounded on the sea bed – could cause ice sheets to collapse.

http://www.newscientist.com/article...r-is-past-its-tipping-point.html#.Usb_xvRdXgw

Lots of room for worry and doubt. Lots of unanswered questions. 2 meters sea level rise over the next 100 years is a reasonable number, but that could be anything from 30 cm to pick a number. In all likely hood it is the hundred years after that (out to 2113-2213) when we will see the big big sea level rises (2m plus).

 

[ferrelhadley]

The UAH team have come in with their figure for global temperature in 2013. An anomaly of +0.236C, fourth behind 1998, 2010 and 2005.

Caveat emptor: It is only one of the 4 many (and several other) datasets used for global temperature, one year tells us little to nothing about trends and the other results will likely be spread across the top 10 years. Notably though, the UAH and RSS tend to show el Nino years in a big way so for a neutral year to make the top 4 is interesting.

 

[Dr Jon]

Just seen
Lack of research linking climate change and floods is a 'scandal'

Questions about the link between flooding in the UK and climate change could be answered within two years, according to a leading scientist.

Prof Myles Allen from Oxford University said the only thing holding back the work was the lack of investment.

Of course there's been no investment. Government prefers to deny there's any problem, especially when such an admission would kipper the property development "industry" in areas like the Thames valley.


Anybody want to buy an exclusive riverside development in Abingdon?

 

[ferrelhadley]

There seems to have been a change in the ENSO forecasts. Last time I checked there was only a 44% chance of an el Nino. Now there seems to be some indications a strong one might be in the offing. But lots of caveats apply.

 

[Dr Jon]

I guess we can expect a lot more of this:
Extreme Weather Wreaking Havoc on Food as Farmers Suffer

“Extreme weather events are a massive risk to agriculture,” said Peter Kendall, president of the U.K. National Farmers Union, who raises 1,600 hectares (3,953 acres) of grain crops in Bedfordshire, England. “Farmers can adapt to gradual temperature increases, but extreme weather events have the potential to completely undermine production. It could be drought, it could be too much rain, it could be extreme heat at the wrong time. It’s the extreme that does the damage.”

 

[ferrelhadley]

The UAH team have come in with their figure for global temperature in 2013. An anomaly of +0.236C, fourth behind 1998, 2010 and 2005.

Caveat emptor: It is only one of the 4 many (and several other) datasets used for global temperature, one year tells us little to nothing about trends and the other results will likely be spread across the top 10 years. Notably though, the UAH and RSS tend to show el Nino years in a big way so for a neutral year to make the top 4 is interesting.

Noaa: 2013 tied for fourth-warmest year on record

The National Oceanic and Atmospheric Administration on Tuesday released its global temperature figures for 2013. The average world temperature was 58.12F (14.52C) tying with 2003 for the fourth-warmest since 1880.

Nasa, which calculates records in a different manner, said Tuesday that 2013 was the seventh-warmest on record, with an average temperature of 58.3F (14.6C).

Non el Nino year.

 

[Dr Jon]

Polar Vortex Ripped in Half by Anomalous Jet Stream

Average temperatures over a broad area of the north polar region are now in excess of 20 degrees Celsius (32 degrees Fahrenheit) above daily norms for this time of year.

Ooooh crumbs!
We got a wibbly-wobbly polar vortex...

 

[ferrelhadley]

Meanwhile in California
Current California Drought Is Driest In State’s History; Scientists Fear ‘Megadroughts’ On Their Way

California is facing a severe water crisis, and experts fear it could get worse. Climatologists report that the 2013-2014 rainfall season is well on its way to becoming California’s driest period in more than 400 years. The country’s most populous state is entering its third year of record-low rainfall, and now scientists are raising the alarm that “megadroughts,” which haven’t been seen in hundreds of years, could be just around the corner.

In 2013, California received an average of just over 4 inches of rain. Downtown Los Angeles, which receives nearly 15 inches of rain during a normal year, only got 3.6 inches in 2013. It's currently California's driest period since it was granted statehood in 1850, and as a result, the Golden State is experiencing shrinking reservoirs, below-average snowfall and record-breaking low flows in several rivers and streams.

“This could potentially be the driest water year in 500 years,” B. Lynn Ingram, a professor of earth and planetary science and geography, said in a statement.

Ingram analyzed the width of California tree rings, which vary based on the amount of rainfall received each year, and she determined that California has not been this dry since 1580. She said periods like this are “very rare.”

Caveat Emptor: no single event can be blamed on climate, this may be natural variability and this does not affect your statutory right to say its all sunspots.

But this could be quite a serious problem looming.

 

[Quartz]

Can we give them some of ours?

 

[ferrelhadley]

 

[teqniq]

Taken from FB but posted by local news outlet who have also posted this on their site

Winter Weather Threatens Northwest Florida

 

[Dr Jon]

Prince of Wales hits out at climate change deniers... labelling them the 'headless chicken brigade'

I'd call them the 'malevolent fuckwit faction', but guess the future monarch has to be polite?

 

[gentlegreen]

He's a weird mixture of contradictions though.
And surely the deniers describe the scientific concensus as the chicken Littles and thereby headless chickens. ?

He's hardly the best ally - shades of a British Al Gore ...

 

[Dr Jon]

He's a weird mixture of contradictions though.
And surely the deniers describe the scientific concensus as the chicken Littles and thereby headless chickens. ?

He's hardly the best ally - shades of a British Al Gore ...

A mascot that the old folks will rally behind, I suspect.

 

[ferrelhadley]

Prince of Wales hits out at climate change deniers... labelling them the 'headless chicken brigade'

I'd call them the 'malevolent fuckwit faction', but guess the future monarch has to be polite?

He can fuck right off.

 

[gentlegreen]

‘It is baffling, I must say, that in our modern world we have such blind trust in science and technology that we all accept what science tells us about everything - until, that is, it comes to climate science,’ he said.

‘All of a sudden, and with a barrage of sheer intimidation, we are told by powerful groups of deniers that the scientists are wrong and we must abandon all our faith in so much overwhelming scientific evidence.

So he disagrees when it comes to homoeopathy but accepts the evidence about climate change.