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NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
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| Neville Gillmore |
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7:10 PM (2 hours ago)
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7:34 PM (2 hours ago)
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ALL This is consistent with other scientists reports. It is tabled over several years chronologicly.For your info and comment.
Regards
Neville
Subject: NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
To: NEVILLE GILLMORE <nevilleg729@gmail.com>
NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
Wednesday, 13 August 2014 10:09 By Dahr Jamail, Truthout | Interview
Robert Bindschadler, NASA emeritus scientist. (Photo: Robert Bindschadler)It is common knowledge in the climate change scientific community that governments around the world had better be planning for a one-meter rise in global sea levels by the end of this century.
What isn’t common is for a world-renowned scientist to warn that there could be a greater rise than that before 2100 – in addition to a catastrophic two to three-meter rise by 2200, and worsening increases thereafter.
NASA emeritus scientist Robert Bindschadler, who worked for 35 years as a glaciologist at NASA Goddard Space Flight Center, is sounding these warnings.
He led 18 field expeditions to Antarctica, and has participated in many other expeditions to glaciers and ice caps around the world. Although he recently retired, he maintains an active interest in the dynamics of glaciers and ice sheets, investigating how remote sensing can be used to improve our understanding of the role of ice in the earth’s climate.
He actively developed applications that measure ice velocity and elevation using both visible and radar imagery, monitor melt of and snowfall on ice sheets by microwave emissions, and detect changes in ice sheet volume by repeat space-borne radar altimetry (using satellites to measure ice sheet thickness).
Bindschadler, who has published over 130 scientific papers, has advised the US Congress and the vice president on the stability of ice sheets and ice shelves and served on many scientific commissions and study groups as an expert in glaciology and remote sensing of ice. He also has degrees in astronomy and physics.
A fellow of the American Geophysical Union (2001), Goddard Senior Fellow (2000), and recipient of the Excellence in Federal Career (1989) award, the Antarctic Service Medal (1984) and the NASA Exceptional Scientific Achievement Medal (1994), Bindschadler continues to be a leader in the public conversation around the climate’s impact on the world’s ice sheets and glaciers.
Truthout recently sat down with Bindschadler for an interview about his concerns about Antarctic glaciers, why scientists are often loath to enter into the debate over anthropogenic climate disruption (ACD), massive sea level rise in the future, and what he thinks can be done.
Dahr Jamail: Over your storied career with NASA and in the Antarctic, can you start off by describing some of the early warning signs of ACD you witnessed?
Robert Bindschadler: There are places where ice sheets in Antarctica are getting a lot smaller a lot faster than we thought.
Our perspective was that we were going to see a very short interval of a very long time interval of change. Everybody knows ice sheets are very slow and they take a long time to respond. That was our perspective too, and that was what I learned about ice sheets when I was in graduate school.
But as the field and satellite data came in, the picture began to change. We were seeing changes on the time scale of a decade. These ice streams could switch on and off, sometimes very suddenly. The time frame of change was growing shorter and shorter.
We had thought millennia to centuries, but now we’re seeing it in decades, and then we started seeing changes of even a few percent of speed in just a year or two. So we were reeling from one season’s discoveries to the next.
So it was a really exciting time to be doing the work because traditional thought was being cast out again and again and again. Last year’s ideas had to be revised with this years data. It was moving that fast.
As data began to come in of more rapid changes, we had the Keeling curve, and things were changing with CO2 and it really was having an impact on human time scales. The increasing awareness of what was happening on the increasingly shorter time scale was happening across the board in earth sciences. Everybody was starting to see this faster pace of change. Especially driven by the increase in greenhouse gases, CO2 really was driving the system faster.
We were driving the system hard and it was responding on observable time frames. We could see in our own data a change from when we started to make measurements, to this year’s measurements. So ice began to be more integrated into the earth sciences view.
We continued to see more dramatic changes happening in shorter time scales, and this was reflected in the series of IPCC reports.
You played an active role with several of the IPCC reports, and knew many of the leading authors. How did the IPCC respond to these rapid chances in Antarctic glaciers and ice sheets and ice shelves you were seeing in the field on your expeditions?
The first of which, in 1990, didn’t even really consider ice sheets because the time frame of interest was the next century. I had an explicit conversation with one of the lead authors of that report, and he said ice sheets weren’t going to be included in the report because everybody knows they aren’t going to change much in the next 100 years.
The next report comes out five years later, and there were published results that ice sheets had changed in Western Antarctica. This is where the big changes were always taking place, and this was the focus of the studies. We had seen enough evidence of past rapid change, so in that second IPCC report what was said was the likelihood of a big change in the Western Antarctic ice sheet was a high risk but low probability event. So we knew the impact of a change there would be large, but we didn’t really understand why it would happen or when it would happen. So it was concluded it was unlikely to happen, because of our ignorance. So it was reported that loss of ice in Western Antarctica might raise sea level significantly, but don’t lose sleep over it.
Then in the third IPCC report [2001] there was a growing awareness of how rapidly the ice sheets were changing right then, and all the hypothetical concern about marine ice sheet instability was not so hypothetical after all. And it might actually be happening right now. But the traditional view that was still dominant within the IPCC authorship group [was] that they didn’t really buy into that yet.
Thus, the numbers they released on projected sea level rise weren’t very extreme because they still didn’t include the dynamic aspect of ice sheets.
Then we get up to the fourth IPCC report in 2007, and we were starting to get some models that incorporated our best understanding of the ice sheets that were showing that there might be some dramatic impact in terms of contribution to sea level. They were acknowledged, with verbiage like, ice sheet dynamics can change rapidly and contribute large amounts of water to cause excess sea level rise, but the dynamics are not well enough understood for predictive capability. The sea level numbers were pretty low, and the words around said they didn’t really know how high they might go. So the story at that time was that we didn’t really know what the numbers were.
I asked the head of Working Group I on that report which had ultimate responsibility for everything that was in the Working Group I report, I said, “All the words say don’t trust the numbers; why are there numbers there at all?” She told me that governments insisted that there be numbers, that they gave them the table and said you put the numbers in this table. Thus, she felt compelled to do that because the report was not going to be accepted by the government until there were numbers in the table.
So now the most recent report is just out, and we worked very hard to use the best models we had of ice sheet dynamics.
Bindschadler believes a rapid disintegration of the West Antarctic Ice Sheet is not out of the realm of possibility, and if it happened it would raise global sea levels by five meters. (Photo: Robert Bindschadler)
What information did you produce that was included in the most recent IPCC report?
When I talk to people who have to plan for what is coming, I tell them they better plan for one-meter global sea level rise by 2100. And that will come in the form of a one-foot rise by the middle of this century, and an additional two feet in the next 50 years. If I were a planner, that’s what I would be planning on.
The first 10 years in this century were really dramatic, in terms of a lot of changes and some big outlet glaciers draining the Greenland Ice Sheet as well as the Western Antarctic Ice Sheet. That’s kind of quieted down a little bit, yet when the models are spun up with the best observations we have and they project into the future, you get results like what recently came out [a scientific report released in May 2014 showing how the continued melting of the massive West Antarctica ice sheet now appears to be unstoppable, and will most likely raise the global sea level 10 feet or more in coming centuries] and that this is irreversible.
It would be irresponsible of the scientific community to give false hope that we won’t see a one-meter rise by 2100. So you’d better plan for that, and it might even be worse.
We are already seeing increasing temperatures of the oceans, and retreating glaciers across much of the globe. Explain the impact of increasing ocean temperatures on Antarctic ice shelves.
A one-degree Celsius temperature increase in the ocean water will increase your glacial melt rate by 10 meters per year in ice sheet thickness. This is a large number, because these ice sheets, including that of the Western Antarctic that is a shelf over the water, are just a few hundred meters thick so it can start thinning pretty rapidly. When you start thinning the ice shelf that essentially opens the valve, because the ice shelves are what are holding the ice sheet back. The ice shelves are corks in the bottle, and we are sure of this, because when the Larsen B ice shelf in the Antarctic suddenly disintegrated, the glaciers that fed that ice shelf suddenly sped up by factors of four and five.
Once you start melting the ice shelves more rapidly from underneath with this warm surface water that opens the valve, more ice leaves the continent, the ice sheet shrinks and the sea level goes up. And this phenomenon is the most pronounced in Antarctica, as it is the greatest impact for melting shelves and ice sheets and causing rising sea levels there on a short time scale.
Over your long career, what examples of the increasingly rapid changes in Antarctica had the most impact on you?
In graduate school we were indoctrinated into the thinking that an ice sheet changing its size significantly on a century time scale was as fast as you could expect. So that’s where I started.
But we found places where the speed of the ice was changing in less than a decade.
Then came the real mind-blowing discovery, which was that an ice sheet flowing into the Ross Ice Shelf would move faster or slower in sync with the tide. We’d never contemplated such dynamism in such a massive ice system stopping and starting on a dime.
This reinforced what we don’t know, and bringing this around to climate change and its impact on sea level, we need to talk about tidewater glaciers, like those in fjords and which are common around Alaska.
We are seeing tidewater glaciers in Greenland and Antarctica now receding episodically. Although the ice sheet is losing mass consistently, it’s through the combination of a few outlet glaciers retreating in this episodic fashion and because there are so many of them and they are asynchronous, it adds up to a smoother reduction in the size of the ice sheet.
So in the last 10 years there have been three very large outlet glaciers that have dramatically expressed this episodic retreat and that has been driving the loss of ice in Greenland. But they now have retreated to their next quasi-stable position so they are relatively quiet right now, but they continue to thin, so we know in the future they will go through another jump. In the case of Antarctica, the recent IPCC report shows us as a model of this happening – that once an ice sheet retreats back past what was holding it in place, retreat becomes irreversible.
So tidewater glacier retreat is clearly being impacted by climate change.
And how does this apply to Western Antarctica?
The West Antarctic Ice Sheet is the only marine-based ice sheet left on the planet.
If we were to see the West Antarctic Ice Sheet go, we would expect to see dramatic retreat, thinning at the margins, production of large icebergs, initial stages of episodic retreats . . . that’s what we think it would look like.
So when you compare that list of characteristics with what we have observed, it’s just a one-to-one match.
So that’s exactly what we see happening. So there is every reason to think that our view of how this irreversible retreat would manifest in the early stages, there is every reason to think that that is what is happening, because that is what we are observing.
What does that do to the one meter predicted sea level rise?
What doesn’t get talked about enough regarding sea level rise by the end of this century is that we never talk about what happens in the next century and the next century and the century after that.
We are just at the beginning stages. If it’s one meter by 2100, then it’s probably two or three meters by the end of the following century. It is an increasing curve.
As more ice sheets come into play, there is enough ice in all the ice sheets to raise sea level 80 meters.
Every time the earth has gotten warmer, there is less ice and higher sea levels. So those mega-facts are hanging out there and they don’t change. So it’s against that backdrop that you have to look at the decade and century time scale change and know that that is just the beginning of a longer sustained trajectory of continued ice loss.
Greenland itself has enough ice to raise sea levels five meters, and West Antarctica about the same size.
Is it possible that the West Antarctic Ice Sheet could collapse in a rapid fashion?
Yes.
What was not included in the recently released report was a higher rate of basal melt. [Basal sliding is the act of a glacier sliding over ground due it being lubricated underneath from meltwater.] That report didn’t include this. Had it included this factor, more sudden retreat, meaning that happening before 2100, could be initiated at any time by putting more heat in the water underneath the ice shelf. That was a modeling study, and the number was chosen based on a number chosen for the water under the ice shelf.
And if that number becomes higher, all of this could happen sooner.
Scientists like yourself are under increasing pressure to produce information about human-driven climate disruption. How do you deal with the challenge and responsibility of communicating your science to the general public?
Jim Hansen, who is a very good friend of mine, has been standing up and taking the arrows.
The shortening of the time scale that glaciers can now contribute to sea level rise and climate change drew me into the debate. And the science is solid. There’s no question about it. Even in the early days it was solid. So I came down hard on the side of yes, it is happening, and I can speak to that when it comes to sea level going up as a result of shrinking ice sheets. That is going to happen.
That gave me my entrance onto the stage where these nasty debates are going on. I wasn’t that far away from the general expectation within the scientific community that said that as long as we spoke from the facts, and stayed secure with our caveats that have to be there, we will be listened to and it will have a positive effect on necessary policies that need to start being put in place. It was that naïve expectation that we’re the experts, and scientists are usually pretty well regarded as credible, and that’s never changed.
But there was such a strong blowback from climate change skeptics and deniers, using their bad science, and we felt there was a failing in the reporting of that, and even though the vast majority of the scientists, and back in those days it was 90 to 10 percent, it would still be reported as an equal debate.
I would say the other side was disingenuous. Once the debate had gone on long enough that observations were collected that showed that some of the other side’s arguments weren’t holding up, and there were fewer and fewer legitimately credentialed earth scientists taking the denial side, so it became a thinner and thinner argument to counter. But yet it was very effectively executed, and earth scientists were effectively drawn into discussing uncertainty, which only served to add currency to the other side, as their currency was doubt.
Bindschadler believes one of the things scientists must learn to do better is communicate the information they produce. (Photo: Robert Bindschadler)We could see where we wanted the information and the dialogue to go, and it wasn’t going that way and there was a lot of frustration around that. In fact, public opinion around climate change as fact or fantasy showed the poll numbers going the way of fantasy. It became frustrating to the point where I just withdrew from all of it. I figured that we are on the right side, and eventually there’ll just be so much data that it will be unavoidable and it’s unfortunate that there’ll likely be some increased suffering cost involved, but I’ve done what I can.
The other thing that led me into a retreat is you would go out there and try to limit your emphasis on caveats and speak more crisply or without the caveats and with more black and white and you would be shot in the back by your colleagues. So I would be quoted in the paper making a rather bold statement and a colleague would call me out and say, well you didn’t mention the uncertainty factor, and sounds like you know more than you know you do. But you have to consider the audience. If all you do is lace it with uncertainty, it gives them reason to do nothing.
But there was not uniform agreement within the scientific community that that was the way to go. So I retreated.
But nothing has changed in the United States.
Others like Jim Hansen and Steve Schneider and some other very high profile people were still out there fighting the good fight and having the courage of conviction and the need to say what they knew. I had a personal conversation with Jim about this. He has suffered emotionally, mightily, for sticking to his decision to not shut up.
I was on a cruise to Antarctica with Al Gore’s climate reality project. Al called me up when I was in the field saying I couldn’t come, but I ended up being able to go as the Antarctic expert on the cruise, along with Hansen and a couple of others. We each had five minutes to present. What was telling is that Jim Hansen gave 60 seconds of science, and eight minutes of his personal story, and he was drawn into this because he saw the future in the models. He cares so deeply about his grandchildren and that is where he finds the strength to keep going.
So I spend a lot of my time speaking of his courage. His example has strongly affected my willingness to get back into the fight, but to fight smarter and more effectively.
But you should know that scientists get no rewards within their own institutions or within their own community, for speaking out like that. But now I don’t need that support. I’m not seeking a promotion. I can just talk about the science. I can use my freedom to really say it, and not be concerned about keeping my colleagues happy.
I talk to my own colleagues still, and I talk about effective communication. We spend too much time talking about what we don’t know, because in the office that is where we do our work: knocking down those barriers that stand between what we know and don’t know, and discovering what we didn’t know.
When we talk to all these other audiences we have to emphasize what we already know.
Trust has become incredibly important. Your credentials may not matter as much as some voice on the radio that an audience is listening to you. I might be branded a liberal as a means of tarnishing the shining credibility I have for being affiliated with NASA.
Given your newfound latitude to speak more freely, what is your message now?
I still keep up on the science so I can speak credibly. But to work on the federal level is so frustrating, and I don’t think there will be significant action there until there is a stronger base upon which it can be built. I continued to hear from the Congress people that I talked to, even if they were a proponent of strong policy for climate change, adaptation and mitigation, their hands are tied in a variety of ways.
So they will all say that until I hear it from my constituents, I’m not going to do anything. Even politicians whose politics I don’t care for that much, they are not going to be the leaders who are going to enact significantly important legislation until they hear it from their constituents.
So that brings me to having conversations with locals because they are with whom you can build trust and have some commonality. The difficult step is getting them to speak out so politicians hear their concerns about this issue. That’s the piece I’m uncertain about how to be effective with, but I think that’s a shorter path to actually getting favorable legislation enacted then traveling to DC and trying to work through Congress.
So I’m trying to find out how to be more effective. But I can’t just set all that I know aside, so my decisions have been to work on a local scale and be a spokesperson for the scientists.
I’m on a local climate action committee now, and doing what I can to help inform people.
I have my four-step program about why you have to accept human-driven climate change, and this is what I tell people now.
Keeling’s curve and the fact that we know CO2 is going up. We know the physics of if you put CO2 into the atmosphere we know what is going to happen. That is physics. You can’t deny that; you can’t deny the Keeling curve that we’ve been pumping it in there. We know how much fossil fuels we’re taking out of the ground, and we know how much we’re burning and it’s traceable. And all the projections of climate models are becoming observable facts.
That’s all you need. It’s real straightforward.
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NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
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Inbox
|
x |
| Neville Gillmore |
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7:10 PM (2 hours ago)
|
|
|
7:34 PM (2 hours ago)
|
|||
|
||||
ALL This is consistent with other scientists reports. It is tabled over several years chronologicly.For your info and comment.
Regards
Neville
Subject: NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
To: NEVILLE GILLMORE <nevilleg729@gmail.com>
NASA Scientist Warns of Three to Four-Meter Sea Level Rise by 2200
Wednesday, 13 August 2014 10:09 By Dahr Jamail, Truthout | Interview
Robert Bindschadler, NASA emeritus scientist. (Photo: Robert Bindschadler)It is common knowledge in the climate change scientific community that governments around the world had better be planning for a one-meter rise in global sea levels by the end of this century.
What isn’t common is for a world-renowned scientist to warn that there could be a greater rise than that before 2100 – in addition to a catastrophic two to three-meter rise by 2200, and worsening increases thereafter.
NASA emeritus scientist Robert Bindschadler, who worked for 35 years as a glaciologist at NASA Goddard Space Flight Center, is sounding these warnings.
He led 18 field expeditions to Antarctica, and has participated in many other expeditions to glaciers and ice caps around the world. Although he recently retired, he maintains an active interest in the dynamics of glaciers and ice sheets, investigating how remote sensing can be used to improve our understanding of the role of ice in the earth’s climate.
He actively developed applications that measure ice velocity and elevation using both visible and radar imagery, monitor melt of and snowfall on ice sheets by microwave emissions, and detect changes in ice sheet volume by repeat space-borne radar altimetry (using satellites to measure ice sheet thickness).
Bindschadler, who has published over 130 scientific papers, has advised the US Congress and the vice president on the stability of ice sheets and ice shelves and served on many scientific commissions and study groups as an expert in glaciology and remote sensing of ice. He also has degrees in astronomy and physics.
A fellow of the American Geophysical Union (2001), Goddard Senior Fellow (2000), and recipient of the Excellence in Federal Career (1989) award, the Antarctic Service Medal (1984) and the NASA Exceptional Scientific Achievement Medal (1994), Bindschadler continues to be a leader in the public conversation around the climate’s impact on the world’s ice sheets and glaciers.
Truthout recently sat down with Bindschadler for an interview about his concerns about Antarctic glaciers, why scientists are often loath to enter into the debate over anthropogenic climate disruption (ACD), massive sea level rise in the future, and what he thinks can be done.
Dahr Jamail: Over your storied career with NASA and in the Antarctic, can you start off by describing some of the early warning signs of ACD you witnessed?
Robert Bindschadler: There are places where ice sheets in Antarctica are getting a lot smaller a lot faster than we thought.
Our perspective was that we were going to see a very short interval of a very long time interval of change. Everybody knows ice sheets are very slow and they take a long time to respond. That was our perspective too, and that was what I learned about ice sheets when I was in graduate school.
But as the field and satellite data came in, the picture began to change. We were seeing changes on the time scale of a decade. These ice streams could switch on and off, sometimes very suddenly. The time frame of change was growing shorter and shorter.
We had thought millennia to centuries, but now we’re seeing it in decades, and then we started seeing changes of even a few percent of speed in just a year or two. So we were reeling from one season’s discoveries to the next.
So it was a really exciting time to be doing the work because traditional thought was being cast out again and again and again. Last year’s ideas had to be revised with this years data. It was moving that fast.
As data began to come in of more rapid changes, we had the Keeling curve, and things were changing with CO2 and it really was having an impact on human time scales. The increasing awareness of what was happening on the increasingly shorter time scale was happening across the board in earth sciences. Everybody was starting to see this faster pace of change. Especially driven by the increase in greenhouse gases, CO2 really was driving the system faster.
We were driving the system hard and it was responding on observable time frames. We could see in our own data a change from when we started to make measurements, to this year’s measurements. So ice began to be more integrated into the earth sciences view.
We continued to see more dramatic changes happening in shorter time scales, and this was reflected in the series of IPCC reports.
You played an active role with several of the IPCC reports, and knew many of the leading authors. How did the IPCC respond to these rapid chances in Antarctic glaciers and ice sheets and ice shelves you were seeing in the field on your expeditions?
The first of which, in 1990, didn’t even really consider ice sheets because the time frame of interest was the next century. I had an explicit conversation with one of the lead authors of that report, and he said ice sheets weren’t going to be included in the report because everybody knows they aren’t going to change much in the next 100 years.
The next report comes out five years later, and there were published results that ice sheets had changed in Western Antarctica. This is where the big changes were always taking place, and this was the focus of the studies. We had seen enough evidence of past rapid change, so in that second IPCC report what was said was the likelihood of a big change in the Western Antarctic ice sheet was a high risk but low probability event. So we knew the impact of a change there would be large, but we didn’t really understand why it would happen or when it would happen. So it was concluded it was unlikely to happen, because of our ignorance. So it was reported that loss of ice in Western Antarctica might raise sea level significantly, but don’t lose sleep over it.
Then in the third IPCC report [2001] there was a growing awareness of how rapidly the ice sheets were changing right then, and all the hypothetical concern about marine ice sheet instability was not so hypothetical after all. And it might actually be happening right now. But the traditional view that was still dominant within the IPCC authorship group [was] that they didn’t really buy into that yet.
Thus, the numbers they released on projected sea level rise weren’t very extreme because they still didn’t include the dynamic aspect of ice sheets.
Then we get up to the fourth IPCC report in 2007, and we were starting to get some models that incorporated our best understanding of the ice sheets that were showing that there might be some dramatic impact in terms of contribution to sea level. They were acknowledged, with verbiage like, ice sheet dynamics can change rapidly and contribute large amounts of water to cause excess sea level rise, but the dynamics are not well enough understood for predictive capability. The sea level numbers were pretty low, and the words around said they didn’t really know how high they might go. So the story at that time was that we didn’t really know what the numbers were.
I asked the head of Working Group I on that report which had ultimate responsibility for everything that was in the Working Group I report, I said, “All the words say don’t trust the numbers; why are there numbers there at all?” She told me that governments insisted that there be numbers, that they gave them the table and said you put the numbers in this table. Thus, she felt compelled to do that because the report was not going to be accepted by the government until there were numbers in the table.
So now the most recent report is just out, and we worked very hard to use the best models we had of ice sheet dynamics.
Bindschadler believes a rapid disintegration of the West Antarctic Ice Sheet is not out of the realm of possibility, and if it happened it would raise global sea levels by five meters. (Photo: Robert Bindschadler)
What information did you produce that was included in the most recent IPCC report?
When I talk to people who have to plan for what is coming, I tell them they better plan for one-meter global sea level rise by 2100. And that will come in the form of a one-foot rise by the middle of this century, and an additional two feet in the next 50 years. If I were a planner, that’s what I would be planning on.
The first 10 years in this century were really dramatic, in terms of a lot of changes and some big outlet glaciers draining the Greenland Ice Sheet as well as the Western Antarctic Ice Sheet. That’s kind of quieted down a little bit, yet when the models are spun up with the best observations we have and they project into the future, you get results like what recently came out [a scientific report released in May 2014 showing how the continued melting of the massive West Antarctica ice sheet now appears to be unstoppable, and will most likely raise the global sea level 10 feet or more in coming centuries] and that this is irreversible.
It would be irresponsible of the scientific community to give false hope that we won’t see a one-meter rise by 2100. So you’d better plan for that, and it might even be worse.
We are already seeing increasing temperatures of the oceans, and retreating glaciers across much of the globe. Explain the impact of increasing ocean temperatures on Antarctic ice shelves.
A one-degree Celsius temperature increase in the ocean water will increase your glacial melt rate by 10 meters per year in ice sheet thickness. This is a large number, because these ice sheets, including that of the Western Antarctic that is a shelf over the water, are just a few hundred meters thick so it can start thinning pretty rapidly. When you start thinning the ice shelf that essentially opens the valve, because the ice shelves are what are holding the ice sheet back. The ice shelves are corks in the bottle, and we are sure of this, because when the Larsen B ice shelf in the Antarctic suddenly disintegrated, the glaciers that fed that ice shelf suddenly sped up by factors of four and five.
Once you start melting the ice shelves more rapidly from underneath with this warm surface water that opens the valve, more ice leaves the continent, the ice sheet shrinks and the sea level goes up. And this phenomenon is the most pronounced in Antarctica, as it is the greatest impact for melting shelves and ice sheets and causing rising sea levels there on a short time scale.
Over your long career, what examples of the increasingly rapid changes in Antarctica had the most impact on you?
In graduate school we were indoctrinated into the thinking that an ice sheet changing its size significantly on a century time scale was as fast as you could expect. So that’s where I started.
But we found places where the speed of the ice was changing in less than a decade.
Then came the real mind-blowing discovery, which was that an ice sheet flowing into the Ross Ice Shelf would move faster or slower in sync with the tide. We’d never contemplated such dynamism in such a massive ice system stopping and starting on a dime.
This reinforced what we don’t know, and bringing this around to climate change and its impact on sea level, we need to talk about tidewater glaciers, like those in fjords and which are common around Alaska.
We are seeing tidewater glaciers in Greenland and Antarctica now receding episodically. Although the ice sheet is losing mass consistently, it’s through the combination of a few outlet glaciers retreating in this episodic fashion and because there are so many of them and they are asynchronous, it adds up to a smoother reduction in the size of the ice sheet.
So in the last 10 years there have been three very large outlet glaciers that have dramatically expressed this episodic retreat and that has been driving the loss of ice in Greenland. But they now have retreated to their next quasi-stable position so they are relatively quiet right now, but they continue to thin, so we know in the future they will go through another jump. In the case of Antarctica, the recent IPCC report shows us as a model of this happening – that once an ice sheet retreats back past what was holding it in place, retreat becomes irreversible.
So tidewater glacier retreat is clearly being impacted by climate change.
And how does this apply to Western Antarctica?
The West Antarctic Ice Sheet is the only marine-based ice sheet left on the planet.
If we were to see the West Antarctic Ice Sheet go, we would expect to see dramatic retreat, thinning at the margins, production of large icebergs, initial stages of episodic retreats . . . that’s what we think it would look like.
So when you compare that list of characteristics with what we have observed, it’s just a one-to-one match.
So that’s exactly what we see happening. So there is every reason to think that our view of how this irreversible retreat would manifest in the early stages, there is every reason to think that that is what is happening, because that is what we are observing.
What does that do to the one meter predicted sea level rise?
What doesn’t get talked about enough regarding sea level rise by the end of this century is that we never talk about what happens in the next century and the next century and the century after that.
We are just at the beginning stages. If it’s one meter by 2100, then it’s probably two or three meters by the end of the following century. It is an increasing curve.
As more ice sheets come into play, there is enough ice in all the ice sheets to raise sea level 80 meters.
Every time the earth has gotten warmer, there is less ice and higher sea levels. So those mega-facts are hanging out there and they don’t change. So it’s against that backdrop that you have to look at the decade and century time scale change and know that that is just the beginning of a longer sustained trajectory of continued ice loss.
Greenland itself has enough ice to raise sea levels five meters, and West Antarctica about the same size.
Is it possible that the West Antarctic Ice Sheet could collapse in a rapid fashion?
Yes.
What was not included in the recently released report was a higher rate of basal melt. [Basal sliding is the act of a glacier sliding over ground due it being lubricated underneath from meltwater.] That report didn’t include this. Had it included this factor, more sudden retreat, meaning that happening before 2100, could be initiated at any time by putting more heat in the water underneath the ice shelf. That was a modeling study, and the number was chosen based on a number chosen for the water under the ice shelf.
And if that number becomes higher, all of this could happen sooner.
Scientists like yourself are under increasing pressure to produce information about human-driven climate disruption. How do you deal with the challenge and responsibility of communicating your science to the general public?
Jim Hansen, who is a very good friend of mine, has been standing up and taking the arrows.
The shortening of the time scale that glaciers can now contribute to sea level rise and climate change drew me into the debate. And the science is solid. There’s no question about it. Even in the early days it was solid. So I came down hard on the side of yes, it is happening, and I can speak to that when it comes to sea level going up as a result of shrinking ice sheets. That is going to happen.
That gave me my entrance onto the stage where these nasty debates are going on. I wasn’t that far away from the general expectation within the scientific community that said that as long as we spoke from the facts, and stayed secure with our caveats that have to be there, we will be listened to and it will have a positive effect on necessary policies that need to start being put in place. It was that naïve expectation that we’re the experts, and scientists are usually pretty well regarded as credible, and that’s never changed.
But there was such a strong blowback from climate change skeptics and deniers, using their bad science, and we felt there was a failing in the reporting of that, and even though the vast majority of the scientists, and back in those days it was 90 to 10 percent, it would still be reported as an equal debate.
I would say the other side was disingenuous. Once the debate had gone on long enough that observations were collected that showed that some of the other side’s arguments weren’t holding up, and there were fewer and fewer legitimately credentialed earth scientists taking the denial side, so it became a thinner and thinner argument to counter. But yet it was very effectively executed, and earth scientists were effectively drawn into discussing uncertainty, which only served to add currency to the other side, as their currency was doubt.
Bindschadler believes one of the things scientists must learn to do better is communicate the information they produce. (Photo: Robert Bindschadler)We could see where we wanted the information and the dialogue to go, and it wasn’t going that way and there was a lot of frustration around that. In fact, public opinion around climate change as fact or fantasy showed the poll numbers going the way of fantasy. It became frustrating to the point where I just withdrew from all of it. I figured that we are on the right side, and eventually there’ll just be so much data that it will be unavoidable and it’s unfortunate that there’ll likely be some increased suffering cost involved, but I’ve done what I can.
The other thing that led me into a retreat is you would go out there and try to limit your emphasis on caveats and speak more crisply or without the caveats and with more black and white and you would be shot in the back by your colleagues. So I would be quoted in the paper making a rather bold statement and a colleague would call me out and say, well you didn’t mention the uncertainty factor, and sounds like you know more than you know you do. But you have to consider the audience. If all you do is lace it with uncertainty, it gives them reason to do nothing.
But there was not uniform agreement within the scientific community that that was the way to go. So I retreated.
But nothing has changed in the United States.
Others like Jim Hansen and Steve Schneider and some other very high profile people were still out there fighting the good fight and having the courage of conviction and the need to say what they knew. I had a personal conversation with Jim about this. He has suffered emotionally, mightily, for sticking to his decision to not shut up.
I was on a cruise to Antarctica with Al Gore’s climate reality project. Al called me up when I was in the field saying I couldn’t come, but I ended up being able to go as the Antarctic expert on the cruise, along with Hansen and a couple of others. We each had five minutes to present. What was telling is that Jim Hansen gave 60 seconds of science, and eight minutes of his personal story, and he was drawn into this because he saw the future in the models. He cares so deeply about his grandchildren and that is where he finds the strength to keep going.
So I spend a lot of my time speaking of his courage. His example has strongly affected my willingness to get back into the fight, but to fight smarter and more effectively.
But you should know that scientists get no rewards within their own institutions or within their own community, for speaking out like that. But now I don’t need that support. I’m not seeking a promotion. I can just talk about the science. I can use my freedom to really say it, and not be concerned about keeping my colleagues happy.
I talk to my own colleagues still, and I talk about effective communication. We spend too much time talking about what we don’t know, because in the office that is where we do our work: knocking down those barriers that stand between what we know and don’t know, and discovering what we didn’t know.
When we talk to all these other audiences we have to emphasize what we already know.
Trust has become incredibly important. Your credentials may not matter as much as some voice on the radio that an audience is listening to you. I might be branded a liberal as a means of tarnishing the shining credibility I have for being affiliated with NASA.
Given your newfound latitude to speak more freely, what is your message now?
I still keep up on the science so I can speak credibly. But to work on the federal level is so frustrating, and I don’t think there will be significant action there until there is a stronger base upon which it can be built. I continued to hear from the Congress people that I talked to, even if they were a proponent of strong policy for climate change, adaptation and mitigation, their hands are tied in a variety of ways.
So they will all say that until I hear it from my constituents, I’m not going to do anything. Even politicians whose politics I don’t care for that much, they are not going to be the leaders who are going to enact significantly important legislation until they hear it from their constituents.
So that brings me to having conversations with locals because they are with whom you can build trust and have some commonality. The difficult step is getting them to speak out so politicians hear their concerns about this issue. That’s the piece I’m uncertain about how to be effective with, but I think that’s a shorter path to actually getting favorable legislation enacted then traveling to DC and trying to work through Congress.
So I’m trying to find out how to be more effective. But I can’t just set all that I know aside, so my decisions have been to work on a local scale and be a spokesperson for the scientists.
I’m on a local climate action committee now, and doing what I can to help inform people.
I have my four-step program about why you have to accept human-driven climate change, and this is what I tell people now.
Keeling’s curve and the fact that we know CO2 is going up. We know the physics of if you put CO2 into the atmosphere we know what is going to happen. That is physics. You can’t deny that; you can’t deny the Keeling curve that we’ve been pumping it in there. We know how much fossil fuels we’re taking out of the ground, and we know how much we’re burning and it’s traceable. And all the projections of climate models are becoming observable facts.
That’s all you need. It’s real straightforward.