Public Release: 19-Nov-2018
The research is the first to show how the melting of the Antarctic ice sheet will affect future climate
University of Arizona
As the Antarctic ice sheet melts, warming of the atmosphere will be delayed by about a decade but sea level rise will accelerate, according to new research scheduled for advance online publication in the journal Nature.
The study is the first to project how the melting of the Antarctic ice sheet will affect future climate, said first author Ben Bronselaer of the University of Arizona, adding that current climate models do not include the effects of melting ice on the global climate.
The entire Earth will continue to warm, but the atmosphere will warm more slowly because more of the heat will be trapped in the ocean, he said
“Warming won’t be as bad as fast as we thought, but sea level rise will be worse,” said Bronselaer, a postdoctoral research associate in the UA Department of Geosciences.
Observations show that the Antarctic ice sheet has been melting faster in recent years.
The UA-led team found that by the year 2100, sea level could rise as much as 10 inches more than the previous estimate of approximately 30 inches by 2100.
“No one had looked at the big picture of what Antarctic ice sheet melting means for the global climate,” he said.
To figure out whether the melting of the Antarctic ice sheet would affect global climate, the research team modified one of the most current climate computer models to include the ice melt.
Adding the melted ice into the team’s model indicated that the global temperature would increase by 2 degrees C (3.6 F) by the year 2065, rather than the year 2053, the team writes.
In addition to slowing warming and increasing sea level, the melting of the Antarctic ice sheet will change precipitation regimes because the tropical rain belt will shift north, said senior author Joellen Russell, who holds the Thomas R. Brown Distinguished Chair of Integrative Science and is an associate professor of geosciences at the UA.
“Our projections indicate the tropical rain belt will shift toward the Northern Hemisphere, making it slightly wetter in the Northern Hemisphere and slightly drier in the Southern Hemisphere than previously predicted,” Russell said.
The team’s research paper, “Change in future climate due to Antarctic meltwater,” is scheduled for online publication in the journal Nature on Nov. 19. A complete list of coauthors and their affiliations is at the end of this release.
The research is part of the National Science Foundation-funded Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) Project. The National Oceanic and Atmospheric Administration and NASA also funded the research.
Russell leads the part of SOCCOM that is charged with improving how the Southern Ocean is represented in the computer models of global climate. The Southern Ocean is the ocean that surrounds Antarctica.
Researchers previously thought the melting of the Antarctic ice sheet would affect only sea level, not the entire climate system.
To test that idea, Bronselaer ran a climate model with and without the ice- sheet melting included. The team included researchers from NOAA’s Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey and from Princeton University. The scientists used NOAA GFDL’s climate model called ESM2M and tested the simulation over the time period from 1950 to 2100.
In addition, they set the level of greenhouse gas emissions for the 21st century using the scenario known as RCP8.5, sometimes called the “business-as-usual” scenario.
Russell and Bronselaer were both surprised by their findings. They did not expect the Antarctic meltwater to affect the global climate system.
Ocean circulation moves heat from the equator to the poles. The heat is then released into the atmosphere, Russell said. However, the team’s new research reveals that the additional freshwater from the melting ice sheet acts like a lid on the waters around Antarctica and slows the release of heat.
“It’s the first new identified feedback on climate in 20 years,” she said. “The melting delays warming – it’s still warming but it will warm less steeply and give us another 15-year grace period.”
Another SOCCOM team that has deployed robotic floats throughout the Southern Ocean that are gathering temperature, salinity, and biological and chemical information about the ocean.
Russell said her next steps are evaluating climate models against the observations from the SOCCOM floats to see what else the models might be missing.
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Bronselaer and Russell’s coauthors on the paper, “Change in future climate due to Antarctic Meltwater,” are Michael Winton of the NOAA GFDL in Princeton, New Jersey; Stephen M. Griffies of NOAA GFDL and Princeton University; William J. Hurlin of NOAA GFDL; Keith B. Rodgers of Princeton University; Olga V. Sergienko of NOAA GFDL and Princeton University; and Ronald J. Stouffer of the University of Arizona and NOAA GFDL.
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“Our projections indicate the tropical rain belt will shift toward the Northern Hemisphere, making it slightly wetter in the Northern Hemisphere and slightly drier in the Southern Hemisphere than previously predicted,” Russell said.
I heard this argument recently here somewhere on radio related to ‘global warming’
Truth is there is no global warming. By my results it is already globally cooling. And it already playing out exactly as I thought it would: warmer and drier summers and cooler and dryer winters at the higher lats.
The beginning of the ‘dust bowl’ drought of 1932-1939 is almost here.
That was one of the worst disasters in northern America.
Click on my name to read my final report on this.
It does stand to reason that as the ice sheet expands further north that it would melt faster.
If they assumed the rate of melting remains constant, then you would see greater sea level rise.
Sadly for them, good for people, the rate of melting would decrease as the sea ice extent recedes back toward the pole. I’m sure in their paper their is a plea that “…with additional funding, faulty estimations could be made with greater precision.”
The climate models remind me of the random paragraph generators.
Enter a random variable and voila!
It also amuses me the wamista’s argument “the models are based on well established physics”.
Someone should inform them that when ice melts in water, the water level decreases. The article says nothing about land ice being added to replace the so-called melting sea ice. The model has the wrong sign for melting ice…
John,
You said, “Someone should inform them that when ice melts in water, the water level decreases.”
Either you stated that poorly, or you don’t understand Archimedes’ Principle.
Clyde
true enough
ice that melts from the arctic does not contribute to sea level increase because the volume of ice is smaller than that of water…
So the increase of water level comes from the ice melting off ice from Greenland and the Antarctic.
Now, remember that the ocean’s levels in the interglacial periods was occasionally 30 m higher than it is today, there is evidence for this in the Cape (South Africa)
my question is: how could this have happened, why?
henryp,
There are several things that I can think of that might be responsible, such as the water that was formerly in glaciers in the northern hemisphere being relocated to Antarctica, or isostatic adjustment increasing the volume of the ocean basins. However, I’m unaware of any research that has looked into quantifying either of those hypotheses.
Clyde
I am informed that the cause of occasional higher sea levels in the interglacial periods must have been due to the so-called Milankovich cycles which proposes a different cycle of earth around the sun and/or inclination.
To those who know: please let me know what could have caused this?
This “settled science” sure changes fast, doesn’t it?
When did modeling come to be equated with research?
Thomas Graney,
You asked, “When did modeling come to be equated with research?”
When it is done for research purposes and it is done properly. That is, insight on the behavior of dynamic systems can be gained from models by conducting classical experiments where a single parameter is allowed to vary and one observes the results. This is then done for all the parameters in turn. One obtains information on the sensitivity of the model to changes, and it can be seen if unreasonable values are generated. Based on that information, one can then make changes in the model to make it more realistic. Thus, one can learn how Nature works, or at least to a level of simplicity that has utility for forecasting.
The problem is, climate modelers have created models with little predictive skill, and instead of focusing on improving the skill, they (and others) are assuming that the models are fully functional simulators and making forecasts based on scenarios. Thus, instead of being first and foremost research tools, they are being used as political tools — in my humble opinion.
Antarctic ice mass data is total misinformation for several reasons. First, it is based on highly unreliable GRACE gravitational data on the total ice mass and thickness. This data is probably wrong, and even if it were correct, it is irrelevant to climate. It is a geology issue only. Climate is what happens at the surface. Thickness and mass are influenced by volcanic activity at the base and is unrelated to atmospheric climate. It is quite possible for Antarctic thickness and mass to be decreasing while climate is at the same time cooling, which it is at the present time.
Second, keeping the false Antarctic warming scare show on the road is done primarily with computer models. It ignores the instrumental data that show a persistent substantial cold anomaly in the sea all around Antarctica.
The continent of Antarctica and the surrounding southern ocean are slowly cooling, and this possibly represents the early initiation of glacial inception. Both glacial and interglacial inceptions are always led by Antarctica.
GRACE measurements are actually very precise (and not significantly different from zero). Unfortunately they can’t distinguish gravitational effects from rocks and ice, so te supposed melt is entirely a matter of GIA (Global Isostatic Adjustment) models. There are several, widely different, and none of them matches actual measurements in Antarctica.
tty
Thanks for highlighting what’s at the core of the GRACE based estimate of Antarctic mass balance. Indeed – almost the entire mass loss signal is the GIA. When an adjustment comprises most or all of a signal, and the measured signal is insignificant, then that is what most people would call unreliable data.
What Antarctic melting????
The study is worthless because it uses RCP8.5.
It’s useless for a lot of reasons. But that is one of the big ones.
A search for “by the year 2100, sea level could rise as much as ” shows that the science is settled!
Webpredictions galore show that we are doomed – and HOW!
“…give us another 15-year grace period.”
Glad to see the end of the world has been postponed for 15 extra years. So, instead of always being now + 30 years, it’s now + 45 years. Got it.
You always look for the money quote-
“To figure out whether the melting of the Antarctic ice sheet would affect global climate, the research team modified one of the most current climate computer models to include the ice melt.”
easy peasy ….yada, yada and then the finale-
“Russell said her next steps are evaluating climate models against the observations from the SOCCOM floats to see what else the models might be missing.”
Needs more grants
In Antarctica, as anywhere else, any outcome is interpreted as showing warming.
Does ice mass decrease? Warming oceans are melting it at the edges.
Does ice mass increase? Then snowfall is increasing due to a warmer and moister atmosphere.
Does it stay the same? Then both of the above cancel each other out.
In all cases, the catastrophic warming story is preserved.
Bronselaer et alia could have saved themselves a lot of bother and embarassment by having a quick look at WUWT’s Sea Ice page.
“In addition to slowing warming and increasing sea level, the melting of the Antarctic ice sheet will change precipitation regimes because the tropical rain belt will shift north, said senior author Joellen Russell”
Because there has been no statistically significant global warming trend since mid-1996, CAGW advocates must come up with excuses to keep the CAGW gravy train chugging along.
There will be many excuses to try to explain why all of CAGW’s projections have been so pitifully devoid from reality.
Alllll the way back on October 30, 2015, NASA announced Antarctic Land Ice has been increasing 80~100 billion tons/year for many decades, NOAA announced that for the first time in a century, Greenland’s net land ice mass increased by 47 billion tons in 2017 and +20 billion tons in 2018, while Arctic Sea Ice Extents bottomed out in 2007 with signs of recovery.
The wheels are to starting to fall off the CAGW gravy train..
“If, then” … without the “if “and an estimate of “then”.
Thats exactly the problem : The WUWT-icepage does not hand any grants , let alone a steady income .
I hate to burst the bubble but any article that starts with a sentence such as “The research is the first to show how the melting of the Antarctic ice sheet will affect future climate” can simply be binned.
Despite the illusion/delusion of far too many “scientists” : We can not predict the future.
Using the verb “will affect” negates this study as science.
The current state of climate/oceanic science does not even include a quantitative understanding of if the Antarctic ice is melting or if the Antarctic is gaining ice mass.
They may have done a study of “If this future then ….” but there is no “will affect” possible.
Kip,
Typical hubris of a true believer they they can reliably predict the future.
Kip, we can bin their study if you want to, but think of the enjoyment it gives to WUWT readers. And to be fair to members of the climate science industry, what else are these prats going to do for a living? – other than a university, who would employ them?
Is the code for the model public information?
“No one had looked at the big picture of what Antarctic ice sheet melting means for the global climate,” he said.
I very much resent people using false history, and noise in data, for purposes of self-aggrandizement.
If only we could find a way to melt the Antarctic ice cap so as to save the planet……
Another “…as the AA ice sheet melts” that is really a ‘what if?’ proposition. They always dishonestly use the present tense in these things and follow up with a reasonable thesis IF this fanciful event were to come to pass. Why does “As the Ice Sheet Melts” come across like a soap opera cliché? Probably because of the ‘communications’ flacks that have come to scientists aid when they were wrestling with how to get dubious science accepted by the masses.
How can you “research” the future? How can you “study” the future? This corruption of language drives me nuts.
So, “the entire earth will continue to warm”, but we won’t be able to see the warmth because it will be hiding in the oceans. How convenient.
Does anyone know if these SOCCOM floats are the same as the ARGO floats, or are they a new addition?
This longterm decadal icemelt effect, observed within the 18 + 19 century, is
described in detail in http://www.knowledgeminer.eu/climate-papers.html.
The paper, PART 8, is dedicated to the period 1600 to 2050 AD.
Therefore, no new conclusions gained out of this Antarctica paper, all
is known and said before – even for century scale time intervals.
The melt of ice, accumulated over centuries, lowers atmospheric temps –
which is the message. There are other (wrong) interpretations that “ice
melt would free ocean surfaces, which are darker, which absorb more
solar energy instead of radiating solar energy back into space, as the bright
ice surfaces do … and thus increasing global temps”.
Now it is admitted that by a higher ice quantity entering the oceans, the
colder the ocean waters get on the ocean surface, thus lowering the
atmospheric temps, because this colder water will cool down the atmosphere.