Rising sea levels of 1.8 meters in worst-case scenario

October 14, 2014 by Gertie Skaarup
The storm surge of Hurricane Sandy reached 2.8 m above mean high tide in New York. In the future less severe storms will cause comparable surge levels due rising sea level. The unlikely worst case scenario for sea level rise this century is estimated to be 1.8 m, which would translate into approximately 20 times more frequent Sandy level surges. Credit: David Shankbone, CC-BY-3.0

The climate is getting warmer, the ice sheets are melting and sea levels are rising – but how much? The report of the UN's Intergovernmental Panel on Climate Change (IPCC) in 2013 was based on the best available estimates of future sea levels, but the panel was not able to come up with an upper limit for sea level rise within this century. Now researchers from the Niels Bohr Institute and their colleagues have calculated the risk for a worst-case scenario. The results indicate that at worst, the sea level would rise a maximum of 1.8 meters. The results are published in the scientific journal Environmental Research Letters.

What causes the sea to rise is when all the water that is now frozen as ice and lies on land melts and flows into the sea. It is first and foremost about the two large, kilometer-thick ice sheets on Greenland and Antarctica, but also mountain glaciers.

In addition, large amounts of groundwater is pumped for both drinking water and agricultural use in many parts of the world and more groundwater is pumped than seeps back down into the ground, so this water also ends up in the oceans.

Finally, what happens is that when the climate gets warmer, the oceans also get warmer and hot water expands and takes up more space. But how much do the experts expect the sea levels to rise during this century at the maximum?

Melting of the ice sheets

"We wanted to try to calculate an upper limit for the rise in sea level and the biggest question is the melting of the ice sheets and how quickly this will happen. The IPCC restricted their projektions to only using results based on models of each process that contributes to . But the greatest uncertainty in assessing the evolution of sea levels is that models have only a limited ability to capture the key driving forces in the dynamics of the ice sheets in relation to climatic impact," Aslak Grinsted, Associate Professor at the Centre for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen

Rising sea levels of 1.8 meters in worst-case scenario
The worst-case sea level projections is shown in red. There is 95% certainty that sea level will not rise faster than this upper-limit. Purple shows the likely range of sea level rise as projected in the IPCC fifth assessment report under a scenario with rising emissions throughout the 21st century (RCP8.5). Credit: Aslak Grinsted, NBI

Aslak Grinsted has therefore, in collaboration with researchers from England and China, worked out new calculations. The researchers have combined the IPCC numbers with published data about the expectations within the ice-sheet expert community for the evolution, including the risk for the collapse of parts of Antarctica and how quickly such a collapse would take place.

"We have created a picture of the propable limits for how much will rise in this century. Our calculations show that the seas will likely rise around 80 cm. An increase of more than 180 cm has a likelihood of less than 5 percent. We find that a rise in sea levels of more than 2 meters is improbable," Aslak Grinsted, but points that the results only concern this century and the sea levels will continue to rise for centuries to come.

Explore further: Sea level rise of 1 meter within 100 years

More information: "Upper limit for sea level projections by 2100." S Jevrejeva et al. 2014 Environ. Res. Lett. 9 104008 DOI: 10.1088/1748-9326/9/10/104008

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JamesG
2.1 / 5 (19) Oct 14, 2014
Don't be scared. These are theories. The Earth hasn't warmed for almost 20 years and they have no idea why. It's smart to plan for what might happen but we need to control the panic the politicians are pushing on us or we will bankrupt countries to correct for what is only a theory.
LariAnn
3.6 / 5 (14) Oct 14, 2014
@JamesG, your statement, "The Earth hasn't warmed for almost 20 years" is a complete lie. What hasn't happened is an INCREASE in the RATE of warming. The almost 20 years you refer to is the period during which the average RATE OF INCREASE in warming has flattened. Warming is still going on and has been going on for the whole period in question, but to reiterate, the RATE OF INCREASE has flattened, and that, if anything, is what might not be understood. Here, to help you understand, is a simple fictional example: Temps are warming by an additional 0.5 degree per decade, so in decade one, the warming is 0.5 degrees, decade 2, 1 degree (0.5 +0.5), decade 3, 1.5 degrees, decade 4, 2 degrees, but then the rate flattens, and for the next two decades, the amount of warming remains at 2 degrees above normal. The rate of increase is flat but warming is still present because temps are still 2 degrees above normal. "No warming" would require that temps DROP all the way back to normal.
PsycheOne
2.3 / 5 (12) Oct 14, 2014
You know, at this point it almost does not seem worth commenting. It is now obvious to anyone but a true believer that no one knows (or can know) the future of our climate. Judging by the comments I've watched over the years, warmists are speaking less and less. And when they do they mainly call people names.
agsb2
4 / 5 (8) Oct 14, 2014
Last time I check, and that was about a week ago, satellites say the sea level is rising at a rate of 3.2 mm/year and it shows no sign of changing
dogbert
2 / 5 (12) Oct 14, 2014
After years and years of doomsday predictions which have never materialized, how do the alarmists back off.

Apparently, they never do.
SciTechdude
3.4 / 5 (8) Oct 14, 2014
After years and years of doomsday predictions which have never materialized, how do the alarmists back off.


After years and years of mounting scientific consensus around the globe, among hundreds of thousands of top-of-their-field scientists that negative changes are taking place around us, and those changes are likely to ramp up unless we change our fundamental way of life to be more sustainable, the science deniers continue to close their eyes, put their fingers in their ears, and go LALALALALALALALALALALALA JESUS IS COMING!

Fortunately their children are paying attention, because they are the ones who are going to inherit the environmental debts racked up by their parents and grand parents. I could show you a hundred studies of environmental degradation, extreme weather that was previously rare but is now increasingly common, extreme flood events, sea level increases consistently over time, 70% of all animals on the planet dying off in the last 30 years, and on and on.
Captain Stumpy
3.8 / 5 (10) Oct 14, 2014
These are theories
@jamesG
a scientific theory is NOT the same thing is a theory that you just "wing out there" from the hip. your comment only proves that you are ignorant of the scientific method as well as most of the overwhelming scientific evidence supporting AGW
feel free to read the following study and refute it ( http://marine.rut..._pub.pdf )... maybe you have a "theory" on how the owrld will miraculously reset back to default like your computer?
your problem, along with all the other "deniers of science" like dogbert, PsycheOne, antiG, ryg, uba, alche, etc is that you read the propaganda and automatically believe it: http://www.drexel...nge.ashx

that's called not checking your facts before opening your big mouth
AKA - being stupid
Captain Stumpy
4.1 / 5 (9) Oct 14, 2014
You know, at this point it almost does not seem worth commenting
@PsycheOne
it would have been far better to stay quiet and thought a fool then to open your mouth and remove all doubt as you have just done
no one knows (or can know) the future of our climate
no one is proclaiming to know the exact future, but you CAN know the basics based upon the well known laws of physics, and develop a probable set of outcomes, etc etc etc
warmists are speaking less and less
then you are not paying attention
and you are usually called names because you are ignoring the blatantly obvious FACTS
you live in a dream: here is a good article about your denial
http://phys.org/n...firstCmt

or are you one of these?
http://arstechnic...nformed/
dogbert
1.6 / 5 (8) Oct 14, 2014
SciTechdude,
After years and years of mounting scientific concensus...


Science is not a democratic process. Facts are important, concensus is irrevalent.
Captain Stumpy
4.6 / 5 (9) Oct 14, 2014
Science is not a democratic process. Facts are important, concensus is irrevalent
@dogbert
whereas this is true, what he is referring to is the overwhelming evidence for AGW and the lack of refute
for instance: http://iopscience.../article
plenty of evidence supporting this article: http://blogs.scie...sagrees/ which says
the number of authors from November, 2012 to December, 2013 who explicitly deny global warming (that is, who propose a fundamentally different reason for temperature rise than anthropogenic CO2). The number is exactly one
then there is this group: http://arstechnic...nformed/
or this one:
http://phys.org/n...firstCmt

the evidence is overwhelming
SciTechdude
5 / 5 (5) Oct 14, 2014
Science is not a democratic process. Facts are important, concensus is irrevalent.


Science is ruled by peer review, which is to say, someone makes a statement, and a number of other people look at that statement with the adjacent evidence provided, and then they take that evidence and run it through their own computer system/mathematical formula/rigorous review process. If they do not come to the same conclusion, or if the math provided by the source doesn't add up, then that statement is given a negative review. However, if there are significantly more positive reviews (replications of the results using the same or similar means of looking at the provided data) that is what we would term "A scientific consensus". The more people who can achieve the same results, the more factually credible a report is. What you just said is basically "The only thing that matters is the truth, and it doesn't matter how many times it's verified". So you're saying you agree with me.
SciTechdude
4.4 / 5 (7) Oct 14, 2014
Me-

After years and years of mounting scientific consensus around the globe, among hundreds of thousands of top-of-their-field scientists...


You quoting me-

After years and years of mounting scientific concensus...


Science is not a democratic process. Facts are important, concensus is irrevalent.


Incidentally, I like how you managed to quote me directly from my comment while somehow misspelling consensus, even though it was correctly spelled in my own post. Do you do that with other types of data as well?
runrig
4.3 / 5 (6) Oct 14, 2014
SciTechdude,
After years and years of mounting scientific concensus...


Science is not a democratic process. Facts are important, concensus is irrevalent.


Err.... but the consensus is based on facts.
The only thing that is fickle in the process is human nature.
Hence the ~3% nay-sayers, who are so persuaded by things other than the "facts".
The scientific evidence is, as the IPCC puts it, is "virtually certain".

http://phys.org/n...ked.html

jwbrighton
1.7 / 5 (6) Oct 14, 2014
Stop lying he was right!
Vietvet
5 / 5 (5) Oct 14, 2014
Stop lying he was right!


My my, what a childish response. What are you, five or six years old?
aksdad
1.4 / 5 (9) Oct 14, 2014
Warming is still going on and has been going on for the whole period in question, but to reiterate, the RATE OF INCREASE has flattened

Wrong, LariAnn. The earth has not warmed over the last 16 years. Here is the satellite data that shows no warming since 1998 (look at the graph):

http://nsstc.uah.edu/climate/

Not only is the RATE OF INCREASE zero, so is the temperature increase. No warming. And no, it's not hiding in the oceans either. The lack of warming is well documented and widely acknowledged, even among notable climate alarmist-scientists.
KDK
1.7 / 5 (6) Oct 14, 2014
Actually, the worst-case scenario is a sea-level FALL, which is going to occur based on the global COOLING cause by Solar Cycle 24 and likely the Milankovitch ice-age cycle as well! The only question is how freaking cold it will get!
aksdad
1.6 / 5 (7) Oct 14, 2014
Hmmm, how do they estimate such a large rise in sea level?

The current rate of sea level rise according to satellite telemetry is about 3.2 mm a year. According to tide gauges it's 1.9 to 2.8 mm a year. There has been no acceleration of sea level rise over the last 2 decades.

http://sealevel.colorado.edu/

Using the highest number, 3.2 mm, we could expect a sea level rise of up to 320 mm (0.32 meters or 12.6 inches) in 100 years. That's well below the LOWEST estimate on the graph in this study.

The large rise in the study comes from model projections. They plug some numbers into a computer, bake until well done, and announce that they're accurate because computers are infallible.

We've been told for some time that glacier loss is accelerating, but apparently that isn't translating into acceleration of sea level rise. Between computer models and measurements, trust measurements.
Porgie
1 / 5 (7) Oct 14, 2014
After this year sea levels will be declining. With a gain of 155,000 square miles of ice in 2014, 2015 will being even more.
MikPetter
5 / 5 (7) Oct 14, 2014
RE
... The earth has not warmed over the last 16 years. Here is the satellite data that shows no warming since 1998 (look at the graph):
http://nsstc.uah.edu/climate/
......

Koff ... actually the graph http://nsstc.uah.edu/climate/2014/september2014/Sept2014graf.jpg shows the warming continuing.
runrig
4.2 / 5 (6) Oct 15, 2014
Actually, the worst-case scenario is a sea-level FALL, which is going to occur based on the global COOLING cause by Solar Cycle 24 and likely the Milankovitch ice-age cycle as well! The only question is how freaking cold it will get!


No, the solar minimum with it's ~11 year cycle is ~0.1% and is barely noticeable on climate. The Earth should be cooling, yes, due it's current orbital characteristics .... but it's way off a dip into ice age conditions.
Anyway CO2 in the atmosphere already would prevent any such IA.
runrig
4.2 / 5 (5) Oct 15, 2014
Not only is the RATE OF INCREASE zero, so is the temperature increase. No warming. And no, it's not hiding in the oceans either. The lack of warming is well documented and widely acknowledged, even among notable climate alarmist-scientists.

It's not is it? really.

I should tell the world's climatologists and oceanographers, I'm sure they's appreciate the benefit of your superior knowledge.
FFS

http://data.giss....;pol=rob
http://www.nodc.n...0myr.png
weathervane
3 / 5 (2) Oct 15, 2014
1.8m change seems ok, but probably not good if you own property in a capital city or a beach front condo. Many cities are pretty crappy anyway and would benefit from being rebuilt in a more equitable and human friendly way, which would create plenty of employment and with careful planning could remove some of the property inequity in society.

On the flip side 1.8m seems pretty tame in the range of measurable marine transgressions you can see visibly in the geological record, so you might want to put that shiny new city slightly higher up just to be on the safe side.
orti
2.6 / 5 (5) Oct 18, 2014
I predict this IPCC prediction will work as well as … an IPCC prediction.
Mike_Massen
2.6 / 5 (5) Oct 18, 2014
JamesG muttered with ignorance
.. These are theories. The Earth hasn't warmed for almost 20 years and they have no idea why..
Theories in Science have a particular meaning, such as a body of evidence offering a high level of certainty...

Eg. Gravity is a theory (with a formula describing the force), the evidence is the observation an item dropped falls to earth with the magnitude of the acceleration consistent with the described formula.

So it is for other theories; Eg. thermodynamics, specific heat, photoelectric effect etc.

Who is the "they" you claim JamesG ?
Earth has to include the oceans, they are 70% or so of surface, there is evidence they have warmed but, JamesG didn't notice.

We do know why as runrig has pointed out and also updated us on the fact the oceans have ~4000x the heat capacity of the atmosphere. Also look here:-
http://www.woodfo...rg/notes

Read & learn please JamesG
Mike_Massen
2.6 / 5 (5) Oct 18, 2014
aksdad oddly claims
shows no warming since 1998 (look at the graph):
http://nsstc.uah.edu/climate/
Beg pardon, from that link do you mean this graph ?
http://nsstc.uah.edu/climate/2014/september2014/Sept2014graf.jpg
Isnt the red above zero an indication of warming ?
Did I read it wrong or did you ?

aksdad claimed
Not only is the RATE OF INCREASE zero, so is the temperature increase.No warming.
Not according to this:- http://www.woodfo...rg/notes

aksdad
And no, it's not hiding in the oceans either.
Last time I looked the NOAA disagrees with you ! Your source of evidence ?

aksdad
The lack of warming is well documented and widely acknowledged, even among notable climate alarmist-scientists.
Are you claiming the 97% of scientists & the IPCC who accept global warming ? - if not then which group please ?

aksdad please answer:-

"How can Adding a GHG with known thermal properties NOT increase thermal resistivity ?"
Mike_Massen
2 / 5 (4) Oct 18, 2014
Link to graph with 'red' bits got munted when posting & editing removes link altogether,
This should work as post shorter too:-

http://nsstc.uah....graf.jpg

Also for aksdad this is of relevance, worthy of close attention:-
http://www.remss..../climate
Mike_Massen
2.6 / 5 (5) Oct 18, 2014
Porgie claimed, likely from hubris, ego & a gambling proclivity
After this year sea levels will be declining.
Why ?
Which group or peer reviewed journals have made this prediction, how much over what period, you know the *details* please so you don't appear as a vague mutterer.

Porgie
With a gain of 155,000 square miles of ice in 2014, 2015 will being even more.
So you are claiming then ice extent will remove water when this extent is floating upon the water, so how does that work ?

Porgie why are you confusing extent with mass, can you not see these are completely different !
JoeBlue
1 / 5 (4) Oct 18, 2014
Mike pulling overtime to get that grant money.

Also, red lobster sucks.
Mike_Massen
2.3 / 5 (3) Oct 21, 2014
JoeBlue couldn't help himself jumping in with
Mike pulling overtime to get that grant money.
Also, red lobster sucks.
If you mean me.
Haven't had a grant since 2001 or so, WAISS or AEDB can't recall so long ago. Ignorance pisses me off, seeing dicks make dumb statements doesn't help the even more "challenged" who might want to understand nothing in nature is simple & occam's razor has issues of metrics and comparative applicability re linguistics in appreciating complexity...

Besides I need good vocab practice since my last uni degree 2010 (and still collecting) to keep up the dialectic and maintain brain cell health as I have the gene for Alzheimers as did my mum, grandma etc !

Cyah, on the other side of Entropy !

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