Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass loss.
Current ice margin recession is led by the retreat of outlet glaciers,
large rivers of ice ending in narrow fjords that drain the interior. We
pair an outlet glacier–resolving ice sheet model with a comprehensive
uncertainty quantification to estimate Greenland’s contribution to sea
level over the next millennium. We find that Greenland could contribute
5 to 33 cm to sea level by 2100, with discharge from outlet glaciers
contributing 8 to 45% of total mass loss. Our analysis shows that
uncertainties in projecting mass loss are dominated by uncertainties in
climate scenarios and surface processes, whereas uncertainties in
calving and frontal melt play a minor role. We project that Greenland
will very likely become ice free within a millennium without
substantial reductions in greenhouse gas emissions.

Plenty of food for thought.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

On 27/06/2019 19:15, Norman Lynagh wrote:
Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass loss.
Current ice margin recession is led by the retreat of outlet glaciers,
large rivers of ice ending in narrow fjords that drain the interior. We
pair an outlet glacier–resolving ice sheet model with a comprehensive
uncertainty quantification to estimate Greenland’s contribution to sea
level over the next millennium. We find that Greenland could contribute
5 to 33 cm to sea level by 2100, with discharge from outlet glaciers
contributing 8 to 45% of total mass loss. Our analysis shows that
uncertainties in projecting mass loss are dominated by uncertainties in
climate scenarios and surface processes, whereas uncertainties in
calving and frontal melt play a minor role. We project that Greenland
will very likely become ice free within a millennium without
substantial reductions in greenhouse gas emissions.

Plenty of food for thought.


I was going to put this in its own thread but it seems related, even
though I'm dealing with sea ice rather than land ice. I've updated my
web-page on the Climate Crisis to include the ice charts for June this
year and one hundred years ago. This time I've also added the August
1919 chart as that shows ice conditions then to be similar to, or worse
than June 2019. The effect of all this extra open water so early in the
melting season will help raise the temperature over Greenland and the
increased humidity should result in increased melt of the ice over
lowish-lying land areas though I'm guessing with the possibility of a
little more snow higher up?

Here's the link:
http://www.scarlet-jade.com/science/...e-change/#data


--
Graham P Davis, Bracknell, Berks. Web-site: http://www.scarlet-jade.com/
“Understanding is a three-edged sword. Your side, my side, and the
truth.� [Ambassador Kosh]
Posted via Mozilla Thunderbird on openSUSE Tumbleweed.

Graham P Davis wrote:

On 27/06/2019 19:15, Norman Lynagh wrote:
Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass
loss. Current ice margin recession is led by the retreat of outlet
glaciers, large rivers of ice ending in narrow fjords that drain
the interior. We pair an outlet glacier–resolving ice sheet model
with a comprehensive uncertainty quantification to estimate
Greenland’s contribution to sea level over the next millennium.
We find that Greenland could contribute 5 to 33 cm to sea level by
2100, with discharge from outlet glaciers contributing 8 to 45% of
total mass loss. Our analysis shows that uncertainties in
projecting mass loss are dominated by uncertainties in climate
scenarios and surface processes, whereas uncertainties in calving
and frontal melt play a minor role. We project that Greenland will
very likely become ice free within a millennium without substantial
reductions in greenhouse gas emissions.

Plenty of food for thought.


I was going to put this in its own thread but it seems related, even
though I'm dealing with sea ice rather than land ice. I've updated my
web-page on the Climate Crisis to include the ice charts for June
this year and one hundred years ago. This time I've also added the
August 1919 chart as that shows ice conditions then to be similar to,
or worse than June 2019. The effect of all this extra open water so
early in the melting season will help raise the temperature over
Greenland and the increased humidity should result in increased melt
of the ice over lowish-lying land areas though I'm guessing with the
possibility of a little more snow higher up?

Here's the link:
http://www.scarlet-jade.com/science/...te-change/#dat
a

Very good stuff, Graham and it's all pointing in the same direction.
The fact that I find particularly alarming is that the atmospheric
concentration of CO2, as measured at Mauna Loa observatory, is
continuing to rise at an ever-faster rate despite the efforts of some
countries to reduce emissions. Even if it flat-lined at its present
level there would still be very substantial climate change locked into
the system, some of which is already becoming increasingly obvious and
some of which may well take milennia to work through. Rather than just
reducing emissions, what is needed is some way of extracting huge
amounts of CO2 from the atmosphere. Unfortunately, I can't see any of
that happening for many decades and I can only see a continuing rise in
the CO2 concentration. We, the human race, have embarked on an
uncontrolled experiment and we may already have passed the point beyond
which the experiment cannot be reversed. As I said in an earlier post,
part of me is glad that I won't be around to see how this all finally
pans out and part of me wishes that I could be around.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

On 27/06/2019 19:15, Norman Lynagh wrote:
Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass loss.
Current ice margin recession is led by the retreat of outlet glaciers,
large rivers of ice ending in narrow fjords that drain the interior. We
pair an outlet glacier–resolving ice sheet model with a comprehensive
uncertainty quantification to estimate Greenland’s contribution to sea
level over the next millennium. We find that Greenland could contribute
5 to 33 cm to sea level by 2100, with discharge from outlet glaciers
contributing 8 to 45% of total mass loss. Our analysis shows that
uncertainties in projecting mass loss are dominated by uncertainties in
climate scenarios and surface processes, whereas uncertainties in
calving and frontal melt play a minor role. We project that Greenland
will very likely become ice free within a millennium without
substantial reductions in greenhouse gas emissions.

Plenty of food for thought.


And 13 times as many sub-glasial slippage planes than had previously
been known about (and not factored into land-ice loss/global SLR presumably)
https://www.bbc.com/news/science-environment-48773778

On 27/06/2019 20:22, Norman Lynagh wrote:
Graham P Davis wrote:

On 27/06/2019 19:15, Norman Lynagh wrote:
Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass
loss. Current ice margin recession is led by the retreat of outlet
glaciers, large rivers of ice ending in narrow fjords that drain
the interior. We pair an outlet glacier–resolving ice sheet model
with a comprehensive uncertainty quantification to estimate
Greenland’s contribution to sea level over the next millennium.
We find that Greenland could contribute 5 to 33 cm to sea level by
2100, with discharge from outlet glaciers contributing 8 to 45% of
total mass loss. Our analysis shows that uncertainties in
projecting mass loss are dominated by uncertainties in climate
scenarios and surface processes, whereas uncertainties in calving
and frontal melt play a minor role. We project that Greenland will
very likely become ice free within a millennium without substantial
reductions in greenhouse gas emissions.

Plenty of food for thought.


I was going to put this in its own thread but it seems related, even
though I'm dealing with sea ice rather than land ice. I've updated my
web-page on the Climate Crisis to include the ice charts for June
this year and one hundred years ago. This time I've also added the
August 1919 chart as that shows ice conditions then to be similar to,
or worse than June 2019. The effect of all this extra open water so
early in the melting season will help raise the temperature over
Greenland and the increased humidity should result in increased melt
of the ice over lowish-lying land areas though I'm guessing with the
possibility of a little more snow higher up?

Here's the link:
http://www.scarlet-jade.com/science/...te-change/#dat
a

Very good stuff, Graham and it's all pointing in the same direction.
The fact that I find particularly alarming is that the atmospheric
concentration of CO2, as measured at Mauna Loa observatory, is
continuing to rise at an ever-faster rate despite the efforts of some
countries to reduce emissions. Even if it flat-lined at its present
level there would still be very substantial climate change locked into
the system, some of which is already becoming increasingly obvious and
some of which may well take milennia to work through. Rather than just
reducing emissions, what is needed is some way of extracting huge
amounts of CO2 from the atmosphere. Unfortunately, I can't see any of
that happening for many decades and I can only see a continuing rise in
the CO2 concentration. We, the human race, have embarked on an
uncontrolled experiment and we may already have passed the point beyond
which the experiment cannot be reversed. As I said in an earlier post,
part of me is glad that I won't be around to see how this all finally
pans out and part of me wishes that I could be around.


From what I see by comparing the behaviour of temperature wrt to CO2
over the past century, there is a 15 year lag built in so zero emissions
by 2050 wouldn't see temperature reach a max until 2065. the 1.5C limit
will be passed in the late 2030s. Another concern is that when industry
failed during the Great Depression, CO2 took a while to flat-line but
temperature started rising as fast or faster than it has done since. I
put this down to reduced particulates from factory chimneys having an
immediate effect. I wonder if there's any chance that a switch to clean
energy will have a similar, but smaller, effect.

--
Graham P Davis, Bracknell, Berks. Web-site: http://www.scarlet-jade.com/
“Understanding is a three-edged sword. Your side, my side, and the
truth.� [Ambassador Kosh]
Posted via Mozilla Thunderbird on openSUSE Tumbleweed.

On Thursday, June 27, 2019 at 8:22:10 PM UTC+1, Norman Lynagh wrote:
Graham P Davis wrote:

On 27/06/2019 19:15, Norman Lynagh wrote:
Interesting article here

https://advances.sciencemag.org/content/5/6/eaav9396


The abstract reads

Abstract
The Greenland Ice Sheet holds 7.2 m of sea level equivalent and in
recent decades, rising temperatures have led to accelerated mass
loss. Current ice margin recession is led by the retreat of outlet
glaciers, large rivers of ice ending in narrow fjords that drain
the interior. We pair an outlet glacier–resolving ice sheet model
with a comprehensive uncertainty quantification to estimate
Greenland’s contribution to sea level over the next millennium.
We find that Greenland could contribute 5 to 33 cm to sea level by
2100, with discharge from outlet glaciers contributing 8 to 45% of
total mass loss. Our analysis shows that uncertainties in
projecting mass loss are dominated by uncertainties in climate
scenarios and surface processes, whereas uncertainties in calving
and frontal melt play a minor role. We project that Greenland will
very likely become ice free within a millennium without substantial
reductions in greenhouse gas emissions.

Plenty of food for thought.


I was going to put this in its own thread but it seems related, even
though I'm dealing with sea ice rather than land ice. I've updated my
web-page on the Climate Crisis to include the ice charts for June
this year and one hundred years ago. This time I've also added the
August 1919 chart as that shows ice conditions then to be similar to,
or worse than June 2019. The effect of all this extra open water so
early in the melting season will help raise the temperature over
Greenland and the increased humidity should result in increased melt
of the ice over lowish-lying land areas though I'm guessing with the
possibility of a little more snow higher up?

Here's the link:
http://www.scarlet-jade.com/science/...te-change/#dat
a

Very good stuff, Graham and it's all pointing in the same direction.
The fact that I find particularly alarming is that the atmospheric
concentration of CO2, as measured at Mauna Loa observatory, is
continuing to rise at an ever-faster rate despite the efforts of some
countries to reduce emissions. Even if it flat-lined at its present
level there would still be very substantial climate change locked into
the system, some of which is already becoming increasingly obvious and
some of which may well take milennia to work through. Rather than just
reducing emissions, what is needed is some way of extracting huge
amounts of CO2 from the atmosphere. Unfortunately, I can't see any of
that happening for many decades and I can only see a continuing rise in
the CO2 concentration. We, the human race, have embarked on an
uncontrolled experiment and we may already have passed the point beyond
which the experiment cannot be reversed. As I said in an earlier post,
part of me is glad that I won't be around to see how this all finally
pans out and part of me wishes that I could be around.

--
Norman Lynagh
Tideswell, Derbyshire
303m a.s.l.
https://peakdistrictweather.org
twitter: @TideswellWeathr

Cement production is of ever increasing importance in CO2 release (& other pollutants) Cross rail & HS2 (if it happens)are major projects contributing to this
These might be of interest
https://ourworldindata.org/grapher/co2-by-source
https://www.theguardian.com/cities/2...ime-cement-tax

The world production of cement is rocketing.

Graham
Penzance