E-mail updates
Follow on Twitter
Subscribe to RSS
Alister Doyle / Reuters file
Experts increasingly recognize that ice melting in Antarctica could push up sea levels dramatically higher in coming decades.
By John Roach, NBC News
Melting glaciers in Antarctica and Greenland may push up global sea levels more than 3 feet by the end of this century, according to a scientific poll of experts that brings a degree of clarity to a murky and controversial slice of climate science.
Such a rise in the seas would displace millions of people from low-lying countries such as Bangladesh, swamp atolls in the Pacific Ocean, cause dikes in Holland to fail, and cost coastal mega-cities from New York to Tokyo billions of dollars for construction of sea walls and other infrastructure to combat the tides.
"The consequences are horrible," Jonathan Bamber, a glaciologist at the University of Bristol and a co-author of the study published Jan. 6 in the journal Nature Climate Change, told NBC News.
Estimating how much sea levels will rise from ice sheet melting is one of the more challenging aspects of climate science. Some evidence suggests recent accelerated melting is related to changes in ocean and atmospheric temperature, though natural variability may play an important role.
In addition, glaciers respond to external forces such as warmer temperatures in different ways, even when they are located right next to each other. As a result, there is tremendous uncertainty in the scientific community over how the melting will affect sea levels over the next century.
Bamber and colleague Willy Aspinall attempted to find clarity in the chaos using a scientific polling technique common in fields such as predicting earthquakes and volcanic eruptions, but until now not applied to climate science.
The pair sent 26 of the world's leading glaciologists a series of questions about the behavior of the Antarctic and Greenland ice sheets. About half replied to the survey in 2010. The respondents were polled again in 2012 to assess the robustness of their answers.
Bamber said this type of approach is "a lot more than an opinion poll." The experts were handpicked to get a representative perspective of world leaders from the ice sheet modeling and observational fields. "We analyzed the results in a very systematic, rigorous, and statistically robust way," he added.
The median estimate from the experts is that the melting ice sheets will contribute 1 foot (29 centimeters) to sea level rise by the year 2100 with a 5 percent chance their contribution could exceed 2.8 feet (84 centimeters). When the effect of thermal expansion (water expands as it warms) is taken into account, the high-end estimate is more than 3 feet (1 meter).
The estimates are higher than the controversial figures in the 2007 report from the Intergovernmental Panel on Climate Change (IPCC) of up to 23 inches (59 centimeters) and higher than the unpublished estimates being prepared for the next IPCC report, said Bamber, who is a review editor for that document and has seen the estimates.
The discrepancy likely reflects added weight given to recent studies that indicate glacier melt has accelerated in recent years in Antarctica and Greenland, and that the West Antarctic ice sheet could partially collapse by the end of this century.
"The numbers we are getting out of our elicitation reflect the fact that the world leaders in this field are now cognizant of the fact that the ice sheets are quite responsive and, in particular, there is a potential for them to make a really quite dramatic contribution," Bamber said.
The greatest drama would be a more than 3-foot rise in sea levels from the combined effect of melting ice and thermal expansion, which the study indicates has a 1 in 20 chance of occurring.
How much of this drama can be attributed to human burning of fossil fuels, the study indicates, remains murky. “There is really no consensus amongst the experts we approached,” Bamber said. “That’s something that we in the scientific community need to address as a matter of urgency.”
John Roach is a contributing writer for NBC News Digital. To learn more about him, check out his website.
Leave a Comment:
It appears to have happened before. Maybe Arizona will become beachfront property. Sad part is with all the contaminants buried they will enter into this vastness of water. On day at a time.
Or we could figure out how to tilt the Earth a little more, so the extra water falls off. It was easier when the world was flat, of course. But perhaps modern science can still find a way.
National Geographic channel covers this issue regularly.
People who think changing to electric cars is "too inconvenient", will find out what real inconvenience is.. You think you hate immigration now, LMAO!
Real inconvenience is moving to Mars. Especially the piano.
Ocean front property is going to become damn cheap....
That puts a whole new perspective on "Beach Front Property"
Why do you think there is a law forbidden the discussion of global warming in North Carolina. Real Estate Org. doesnt like that talk when trying to sell beach fronts.
Omg, I never realized that about NC. I saw that thing on TV about how they are against believing in global warming, but I didn't put 2 and 2 together....
Doug, it was more on the water level rising, but you and everyone else got the point.
I don't think we have to wait that long. The melt is accelerating in spite of the right-wing denial that science really works.
Even if you dont agree with global warming/climate change, what do you have against cleaning up our environment? Do we agree that we can clean up the sulfur, mercury, and other toxins being put into the atmosphere and air we breath? There is technology help with the environment. I like clean air and water. Its cost a little more but its worth it.
I will tell you this... in 2100 the world would only wish it was 3 feet.
Walmart is the blame and Bush too!
Maybe it's just me but, New York City would be very cool under water. The new Venice.
For all those saying that the oceans will rise 3 ft are nuts. First the ice that is on the water right now wont raise the ocean. If you don't believe me get a glass of water and put some ice cubes in it and let them melt. There will be no rise of the water in the glass after the ice melts. For ALL those that say we should switch to renewable fuel you have no idea of what you suggest. Most everything we use or make today has to have petrolium product to make them so realistically we can't till we find a replacement for oil.
Well there you go! Proof positive that tens of thousands of PhD's are wrong.
Your special-ed class must be sooooo proud of you!
Most of the ice isnt in the water.
GOD most so called experts forget how to do simple things. Look at Einstein he was a mathematical genius but couldn't do simple math problems. Just because you have a phd doesn't mean you know everything.
Now wait just a cotton picking minute -god and Freedom4Everyone, joejoe did the experiment. He must be a scientist. Man am I relieved!
PS: Last time all the ice melted, sea levels rose 390 feet above where they sit today. This has happened more than once. Earth still has the same amount of water as before.
390 feet means most of the eastern half of N.America will be under water. Only the mountain ranges will stay above. Making for island chains and so forth. 4/5ths of the worlds population lives where it will be underwater. Scientists are predicting 500 years until all the ice melts. It will accelerate, melting more each year than the last.
We cannot stop using or drilling for Oil until we have a Viable alternative. Yes Solar and Wind can help. For instance, you cannot fly fighter jets on Solar or Wind. Just like mining for coal. Can you make Steel without Coal?
Sure we can. We just have to give up some stuff. The alternative is ALOT worse.
Sadly people will have to learn this the hard way.
So there's no actual science here, just a poll of people who are already on record as being global warming alarmists.
it's true that the science of climate change is not exact as far as predicting how much will happen when. but, we do have positive data on what has happened in the last century. warming has occurred faster in the last 100 years than it had in the 500 years before that combined. the coincidence that the industrial revolution came about at just the same time, is probably not a coincidence.
the truth is, as stated above that we have lived in a relatively calm period in earth's history and that the norm is much more violent swings in temperatures. that's a question we have to ask why, also? what has been different over the last say, 125,000 years that wasn't there before? perhaps because the earth is slowing down, (it is), the moon is moving farther away (it is) and therefore not having the same effect on our oceans as it has in the past...who knows? i'm not a scientist, but....all of this is a mute point.
who cares why the earth is heating up and if that is going to lead to an ice age or not? who cares if we have contributed to this a little or a lot? shouldn't we be, as stewards of this beautiful planet that God (the universe) gave us, take better care of it? even if burning fossil fuels hasn't exaserbated the climate change, isn't clean air more beneficial, more desirable than air that smells of gasoline? would it be such a terrible thing to have water that is clean and air that isn't poison? for all you conservatives who think liberals are so evil please answer me. is it a BAD thing to want clean and air and water? is there something WRONG with trying to keep preserves for animals? is your world view that we should just slash and burn and take and kill and let our descendants deal with the aftermath? really, don't just throw back some empty insult, because i don't care what you might think of me personally. really, i don't care, because i have no respect for any of you. but, i would really like to understand your point of view and why it is SO wrong to want to live in a clean world. do any of you have an answer as to why filth in the sky and water is the RIGHT way and mine is the wrong?
when i was growing up, i didn't know one person who had asthma. today, what? 35% of all americans have some form of asthma or related illness? why the pandemic of breathing problems. couldn't be the poison in the air, could it? no, of course not. it's got to be the liberal agenda that causing that.
Global warming is a myth, so says the all powerful man who lives in the sky. Just ask a conservative, they'll tell ya.
So the news here is that a poll of people already identified as global warming alarmists think we should be alarmed about a speculative sea level rise. Very surprising.
Who cares about the stinken environment other then the "tree" huggers. Drill baby drill,don't worry oil companies never spill. Besides prayer solves "everything" Amen.
Thankfully the North Carolina legislature has outlawed coastal sea level rise in their state, otherwise they could be in trouble.
As a scientist, human effects on global warming are irrelevant. We can't prevent it or change its outcome, but we should prepare. This would involve dikes, levies, and any other water containment system along all water ways.
If that's your answer then you are in NO way a scientist. You are in NO way a scientist. Oh, and by the way, you are NOT a scientist.
I believe my Pastor Bobby Joe over any Liberal atheist scientist! Pastor Bobby Joe know all! He told me global warming is a hoax started by Satan,I believe my pastor and Sarah Palin too! You betcha!.
Finally! I won't have to drive 60 miles to the ocean, I will have ocean front property. I just hope they clean up the resulting mess so it doesn't foul the new beach that I am building.
I agree totally that the planet is warming up. What I do not agree with is that Man is causing it. Al Gore's "Proof" was been refuted to an extent. There is Proof that this planet has been going through cycles since it first formed. There is Proof that we have had Ice Ages and Mini Ice Ages through out the history of the planet. Something caused the ice to melt then. I just want someone to Prove to me it is Man doing it and not the increase in solar activity or another cycle the planet is going through without just telling me to shutup because I'm for big Oil destroying the planet. There is evidence on both sides. Just because someone disagrees with you does not mean they are paid off by any one group for either side.
People should and do ask questions about both sides of this debate. Anyone who blindly accepts either point of view is an idiot as far as I am concerned. I am just asking for proof it is my car that is causing it when things have warmed up and cooled off many many times through out history.
Carbon dioxide levels have risen steadily with industrialization. Our temps have risen in lockstep.
I dont believe in coincidence like that. Especially when the science supports such an outcome.
What caused the previous warming trends that ended the Ice ages? What caused the cooling trends that brought on the Ice Ages?
There are numerous mechanisms that can cause it, and in different times they have all played a role. Solar and Volcanic activity, Comet and Meteor strikes, our path through the universe as our Solar System moves through the Galaxy on its 25,000 year orbit. etc.
There are also many things that happen on earth that also effect the cycle. Lots of forest fires can effect the weather. Thats just one.
I agree wholeheartedly that there are many reasons that could cause temps to rise or lower. There are studies that say at certain times CO2 levels have been extremely high much higher than they are now. My biggest issue with all this is we just do not know exactly whats causing it. We are going through very high solar activity right now. A couple years ago there was a Lull in the solar flares and temps cooled off. I remember reading that due to the Solar activity being less there was a concern that it would cause temps on earth to cool and there by causing people to be less concerned of climate change.
I agree we need to take care of this planet. I agree clean air is a good thing. I honestly do. Thing is we really do not know what "Normal" is for this planet. There is nothing wrong with questioning either side of the debate. There are scientists on both sides who agree or disagree. We cannot stop drilling for Oil. There is no viable alternative to Oil. Solar and Wind help but right now they aren't a solution. Let's say they stop drilling for Oil today and stop selling gasoline tomorrow. Is there a way to ship goods around the globe? Transport people long distances? Replace plastics? Can you fly Fighter Jets on Solar or Wind? Be realistic if the US doesn't have a way to defend it's self someone will start looking for a way to remove us.
We don't need to stop using all Oil. Just non-commercial use. Trucks, trains and freighters, moving freight, wont be a problem. But billions of cars are.
We don't need to stop using all Oil. We just need to stop burning it wholesale. Not only that, it would extend our supply, which wont last forever. At the rate we are burning it, it will run out in a hundred years or so. Changing to commercial and military use only, would extend that significantly. We should only be burning gas, where we have to. Everything else that we can do without using gas, should be electric. And too bad if it isn't as good.
Cars are not the problem. They account for a statistically insignificant amount. If you want to do something, be sure it is useful and not a feel good action. Commercial transportation pollutes many times more than private use. Industrial is even worse. As someone who has spent years in the environmental field, there are far more important problems than CO2 production, they just don't get the attention.
At those periods of times the temp was also much higher. THAT is the point we are trying to get people to understand. The two, high CO2 and high temp, go hand-in-hand. There's an initial lag period where the temp lags behind the increase in CO2, but when it begins to build momentum the results do NOT bode well for humans.
In my opinion, that's a good thing for the planet. Once humans figured out how to manipulate the environment to suite their need (greed) it was all over for anything (animals, forests, rivers, etc) that stood in the way. And, as the human population continues to explode the situation will only get worse...MUCH worse.
Case and point. The last decade or so the sun was in a lull and yet the temps continued to climb. Now the sun is going into its higher output phase, so what do you think is going to happen to the temps now!?? Like I said, NOT a good outlook for anyone or anything.
Global warming is a Marxist,Communist anti-Christian conspiracy! Pastor Booby Joe told me that!
Them Liberal Scientists with their fancy Marxist,Communist college degrees think they know more then my pastor Bobby Joe,he has a GED! He's very bright and a man of God!!!!
Prayer will solve any global warming,because prayer solves everything!
Sea level rise
Rise level, rise