New study about the rise in global sea levels

247
119
Here is the BBC article, I've read today.
Conclusion from the original study:
.... We find it plausible that SLR could exceed 2 m by 2100 for our high-temperature scenario, roughly equivalent to business as usual. This could result in land loss of 1.79 M km2, including critical regions of food production, and displacement of up to 187 million people (38). A SLR of this magnitude would clearly have profound consequences for humanity.
This sounds really alarming to me.
 
Last edited by a moderator:

davenn

Science Advisor
Gold Member
8,641
5,544
This sounds really alarming to me. How many warnings/studies is needed to make politicians (and people in general) listen to the scientists?
You are treading on thin ice with this subject
Generally, the topic of global warming is a forbidden subject




Dave
 
247
119
Thanks Dave, I realize that the topic might be perceived sensitively. But is it a sufficient reason to avoid any discussion?

I have carefully read the Policy, and I believe that I haven't break any rule so far. I have provided a reference to a peer-review journal. Also, I rather submitted the thread under General Discussion, because I haven't come with any technical/scientific question. I am more or less curious about the sociological/psychological aspect of this topic. What particularly I cannot understand is the passivity, lethargy or understatement that I can observe when discussing this topic in my surroundings or when I see politics to deny the threat.

If mentors decide that the thread is not consistent with PF rules and close the discussion, I will accept it, of course.
 
247
119
ah, I see the thread was moved to Earth Sciences meanwhile...
 

fresh_42

Mentor
Insights Author
2018 Award
10,424
7,114
Thanks Dave, I realize that the topic might be perceived sensitively. But is it a sufficient reason to avoid any discussion?

I have carefully read the Policy, and I believe that I haven't break any rule so far. I have provided a reference to a peer-review journal.
Which is fine.
Also, I rather submitted the thread under General Discussion, because I haven't come with any technical/scientific question. I am more or less curious about the sociological/psychological aspect of this topic.
Which is not so fine, because here you open the doors for political statements and anything will be allowed to say, since you cannot reason on psychological effects unless supported by a study.
What particularly I cannot understand is the passivity, lethargy or understatement that I can observe when discussing this topic in my surroundings or when I see politics to deny the threat.
Which again is about human behavior. I cannot understand murder, nevertheless it happens all the time.
If mentors decide that the thread is not consistent with PF rules and close the discussion, I will accept it, of course.
That's why I moved it to earth. We can debate the paper and its implications, but not the politics behind.
 
247
119

berkeman

Mentor
54,960
5,190
I recently participated in "Hazard Mitigation" studies for two local cities, and since they border the San Francisco Bay, SLR and inundation were part of the studies. One complaint from the folks on the committee (including some representatives from the local Water Boards) was that the studies of SLR in the Bay Area varied quite a bit in their models and results. Still, we looked at various models and used them to bracket the minimum and maximum expected SLR in our area, and used that in our Hazard Mitigation planning (and infrastructure improvement planning).

The USGS website has some good resources, including links to recent studies. We used the 1.0m to 1.9m SLR predictions by 2100 and the USGS Inundation Maps in our planning...
Rising Concerns

Accelerating sea-level rise (SLR), shifting precipitation patterns, and frequency and intensity of storms will affect coastal ecosystems, including salt marshes. Global sea-level rise projections range from 1.0 to 1.9m by 2100 (IPCC 2007; Jevrejeva et al. 2010; Vermeer and Rahmstrof 2009), which will result in the loss of salt marshes and their associated wildlife species.

It is the aim of our program to provide site specific sea-level rise predictions to land managers through the intensive collection of field data and innovative predictive modeling. In 2009 and 2010, thousands of elevation and vegetation survey points were collected in salt marsh at 12 sites surrounding San Francisco Bay. The elevation data was synthesized into a continuous elevation model for each site, providing land owners valuable baseline data.
 
Last edited:

Evo

Mentor
22,857
2,314
To the OP - We humans need to understand that as we come out of the last ice age that melting will continue . Human activity may be accelerating what would happen anyway. We need to realize that just because we planned cities on coasts and like things the way they have been the past couple of generations does not mean that they can or should remain that way. Things always change.

Look at history. Look at all of the cities we are finding under water. Look at the settlements we are finding that were destroyed under glaciers. Look at the sea fossils we are finding at the top of mountains. Where I live now was once a sea. New York City was once under a glacier 2,000 feet high.

We need to accept that we planned and built without understanding the impact that natural climate change would eventually make. Now that it may be speeding up, people are saying that it can't happen?

Anyway, enough of the panic about changes, change will happen. We don't discuss the repercussions of the changes, we only discuss the science if you wish to understand the science behind what is happening.
 

Evo

Mentor
22,857
2,314
I recently participated in "Hazard Mitigation" studies for two local cities, and since they border the San Francisco Bay, SLR and inundation were part of the studies. One complaint from the folks on the committee (including some representatives from the local Water Boards) was that the studies of SLR in the Bay Area varied quite a bit in their models and results. Still, we looked at various models and used them to bracket the minimum and maximum expected SLR in our area, and used that in our Hazard Mitigation planning (and infrastructure improvement planning).

The USGS website has some good resources, including links to recent studies. We used the 1.0m to 1.9m SLR predictions by 2100 and the USGS Inundation Maps in our planning...
This is the type of common sense things we should be doing to address the changes and how we should adapt.
 

BillTre

Science Advisor
Gold Member
2018 Award
1,054
1,593
Look at the settlements we are finding that were destroyed under glaciers.
I don't know of any settlements that have been found that were destroyed under glaciers.

Anyway, enough of the panic about changes, change will happen. We don't discuss the repercussions of the changes, we only discuss the science if you wish to understand the science behind what is happening.
This is the type of common sense things we should be doing to address the changes and how we should adapt.
These two statements seem to be in conflict with each other. Discussing repercussions is preliminary to addressing the changes and how we should adapt to them.
The panic aspect just accentuates the seriousness of the conditions that some people perceive.

The main difference between our current climate crisis and previous changes in climate that did not involve humans is the rate of change. Outside of the Chicxulub impact and some catastrophic events like the formation of the Columbia gorge, most of these changes are thought to have occurred slowly over extended periods of time. The rates of change we are seeing today are on a human's historical time scale, no on a geolgoical time scale that previous big changes are thoguht to have occurred over.
The rapid rate of change is what is seems really threatening to me, since the biological processes that we all depend upon will not be able to keep up with ordinary evolutionary processes. This is added to by non-climate changes that humans have been involved in like, distribution of invasive species and habitat destruction. We therefore may have to make our own changes to organisms to maintain their important ecological functions in the face of these changes. This is an approach that is slowly being developed.

By the way, here is a NY Times story about a town in the mid-west where a similar approach to @berkeman's, in a Republican (or conservative if Republican is too political) area where they want to make changes to deal with ongoing weather issues (has to do with floods), but do not want to get into climate change issues for political reasons. I support this approach because it is currently more feasible in the real (and political) world in which we live. It does not seem to me to be the best approach since it is ignoring certain relevant information that could be useful.
 

jim mcnamara

Mentor
3,473
1,685
247
119
We humans need to understand that as we come out of the last ice age that melting will continue .
By "last ice age", do you mean Last Glacial Period (ending around 11,700 years ago)?
I am not sure you are correct with the continual melting since then. Let me quote from this study:
Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<5000 years ago), culminating in the coolest temperatures of the Holocene during the Little Ice Age, about 200 years ago.
... it suggests a cooling trend lasting over 5000 years in this interglacial period. See also the graph of Global Temperature Anomalies (figure B) taken from the same study:
Mod note: Graphs removed due to paywall violation, see link for graphs.
 
Last edited by a moderator:
247
119
Human activity may be accelerating what would happen anyway.
Yes, maybe. But saying "that would happen anyway" looks to me like we are refusing to take responsibility for that...

We need to realize that just because we planned cities on coasts and like things the way they have been the past couple of generations does not mean that they can or should remain that way. Things always change.
Agreed, the current living style is not sustainable from long-term point of view.

We need to accept that we planned and built without understanding the impact that natural climate change would eventually make.
It is hard to blame humans at the the earlier stages of the industrialization, because they didn't understand the possible consequences of combustion of fossil fuels and other negative activities. No data and no studies were available to predict climate changes. But now, we are in different situation. We have many proofs that currently observed climate changes are caused mainly by human activities. We have also many studies predicting negative scenarios of the further climate evolution (within some uncertainties of course). Despite of that, we do very little to mitigate the consequences. I don't find any excuse for such behavior.

And that annoys me, because in my opinion, humans are capable to take responsibility for their actions and to mitigate the negative impacts of their behavior if there is enough of will-power. Let me provide a positive example: Montreal protocol, which led to the reduction of substances that deplete the atmospheric ozone layer. It is not perfect, but it is working, quote from this report:
The Montreal Protocol is working: There is clear evidence of a decrease in the atmospheric burden of ozonedepleting substances and some early signs of stratospheric ozone recovery
I am not naive, we cannot revert all negative changes which were already done. But we should do our best to not continue in this trend.


EDIT:
In the sense of post #5, I will not contribute in this line of discussion anymore. It is truth, it could be never-ending story. I will constrain my contributions only to the scientific papers, and facts.
 
Last edited:

Evo

Mentor
22,857
2,314
By "last ice age", do you mean Last Glacial Period (ending around 11,700 years ago)?
I am not sure you are correct with the continual melting since then
I should have referred to it as the Holocene for clarity. "The Holocene, starting with abrupt warming 11,700 years ago, resulted in rapid melting of the remaining ice sheets of North America and Europe. The retreat of glaciers altered landscapes in many ways and is currently still acting as a result of climate change. " As I said.

The Holocene ( /ˈhɒləˌsiːn, ˈhoʊ-/)[4][5] is the current geological epoch. It began approximately 11,650 cal years before present, after the last glacial period, which concluded with the Holocene glacial retreat.[6] The Holocene and the preceding Pleistocene[7] together form the Quaternary period. The Holocene has been identified with the current warm period, known as MIS 1. It is considered by some to be an interglacial period within the Pleistocene Epoch.[8] (
An interglacial period is a geological interval of warmer global average temperature lasting thousands of years that separates consecutive glacial periods within an ice age. The current Holocene interglacial began at the end of the Pleistocene, about 11,700 years ago.)

But, let's both get back to the science of understanding why climate changes. You sounded a bit worried and I wanted you not to be. As Berkeman pointed out, there are level headed people that are using the information to make decisions to mitigate damage and make proper decisions going forward, so yes people are addressing the issues.
 

Evo

Mentor
22,857
2,314
By "last ice age", do you mean Last Glacial Period (ending around 11,700 years ago)?
I am not sure you are correct with the continual melting since then. Let me quote from this study:

... it suggests a cooling trend lasting over 5000 years in this interglacial period.
That study is from 2013! Sorry you should check your sources to make sure they are not outdated. See my reply to you above.
 
247
119
"The Holocene, starting with abrupt warming 11,700 years ago, resulted in rapid melting of the remaining ice sheets of North America and Europe. The retreat of glaciers altered landscapes in many ways and is currently still acting as a result of climate change. " As I said.
This text you have updated to your post #14, does it come from this wikipedia article: Holocen glacial retreat? Just at the beginning there is a warning:
This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these template messages)
This article needs additional citations for verification. (July 2011)

This article possibly contains original research. (July 2011)
Could you please provide a more reliable source? On my side, I have requested access to this article and waiting for approval:
The early Holocene sea level rise (DE Smith, S Harrison, CR Firth, JT Jordan)
This figure should come from the article (I will confirm once I get the access):

EDIT:
I have removed the figure, in order to not violate any copyrights. However, the same figure can be seen on this wikipedia link.


It looks like during last 2000 years the sea levels were approximately constant, which suggest that retreat of glaciers during this period was zero, or at least very close to zero. To confirm, it would require more detailed data. Moreover, between 4000 and 3000 years ago, the data suggest that the sea levels might be even decreasing!
 
Last edited by a moderator:
247
119
That study is from 2013! Sorry you should check your sources to make sure they are not outdated. See my reply to you above.
It doesn't mean the study is outdated. As per Info&Metrics of the article, I don't see any significant decreasing trend in the usage of the article since 2014. It seems it is still being frequently quoted. In the wikipedia articles you can find much older references.
 
247
119
For future discussions in the topics related to climate changes, is it OK if I use wikipedia articles as a reference?

From the policy/rules mentioned in the post #2:
CC/GW threads in this forum are intended for discussion of the scientific content of well-researched models of weather, climatology, and global warming that have been published in peer-reviewed journals and well-established textbooks.
So I thought that wikipedia is not accepted reference for the CC/GW topics. But as it was already used in this thread, I am wrong apparently. To work with peer-reviewed papers requires much more effort, and many times the papers are not available to public users. So indeed, it might be more easier and quicker to use wiki (although not fully reliable).

Thanks in advance for your feedback!
 

Evo

Mentor
22,857
2,314
Could you pls provide a more reliable source?
What, an explanation of Holocene being the interglacial warm period we are currently in?

Currently, we are in a warm interglacial that began about 11,000 years ago. The last period of glaciation, which is often informally called the “Ice Age,” peaked about 20,000 years ago. At that time, the world was on average probably about 10°F (5°C) colder than today, and locally as much as 40°F (22°C) colder.

It doesn't mean the study is outdated. As per Info&Metrics of the article, I don't see any significant decreasing trend in the usage of the article since 2014. It seems it is still being frequently quoted. In the wikipedia articles you can find much older references.
Your study wasn't relevant to my response, I was addressing the current warm interglacial (now) and you were posting graphics dating back thousands of years, why, I have no idea.
 

Evo

Mentor
22,857
2,314
For future discussions in the topics related to climate changes, is it OK if I use wikipedia articles as a reference?

From the policy/rules mentioned in the post #2:

So I thought that wikipedia is not accepted reference for the CC/GW topics. But as it was already used in this thread, I am wrong apparently. To work with peer-reviewed papers requires much more effort, and many times the papers are not available to public users. So indeed, it might be more easier and quicker to use wiki (although not fully reliable).

Thanks in advance for your feedback!
I wasn't addressing the climate change science issue of the thread, I was addressing "you" to try to put "you" at ease, and I went on to say to move past the panic as we only address the science, if you wanted to learn.

So the answer is no, if you wish to discuss the science, then please go by the rules.
 

fresh_42

Mentor
Insights Author
2018 Award
10,424
7,114
I wasn't addressing the climate change science issue of the thread, I was addressing "you" to try to put "you" at ease
I just read in a serious news magazine (https://www.spiegel.de/wissenschaft/natur/ozonschicht-killer-quelle-mysterioeser-fckw-emissionen-entdeckt-a-1268733.html) that China still produces CFC-11, 32 years after China signed Montreal.

It is difficult to keep calm if you read those news on a regular basis. Three countries are responsible for the vast part of emissions and neither of them actually cares.
 

Evo

Mentor
22,857
2,314
I just read in a serious news magazine (https://www.spiegel.de/wissenschaft/natur/ozonschicht-killer-quelle-mysterioeser-fckw-emissionen-entdeckt-a-1268733.html) that China still produces CFC-11, 32 years after China signed Montreal.

It is difficult to keep calm if you read those news on a regular basis. Three countries are responsible for the vast part of emissions and neither of them actually cares.
It's upsetting, but panic and despair won't help, it will just make you sick, level headed action is the best course if you want to get involved.

Anyway, we're still going off topic. :smile:
 

BillTre

Science Advisor
Gold Member
2018 Award
1,054
1,593
Here is a Science mag news article on the CFC-11 issue.

They seem to be coming from certain areas of the country and not really legally.
To quote the rticle:
“The Chinese have been doing the best they can” to identify and shut down the rogue operations, Rae says. “But regulators have real trouble keeping tabs on what is going on” throughout the country.
Its my feeling that this will probably be corrected.
 
247
119
I wasn't addressing the climate change science issue of the thread, I was addressing "you" to try to put "you" at ease, and I went on to say to move past the panic as we only address the science
Evo, I appreciate your concern, but I can assure you that I do not panic. I live around 500 km from the nearest coast, so the increasing sea levels are not the immediate or direct threat to me. What makes me worried (but not panicking yet) are the further consequences of such evolution. With all due respect, this discussion is not making my worries to disappear. But that is OK, it is not the aim of this discussion.

Your study wasn't relevant to my response, I was addressing the current warm interglacial (now) and you were posting graphics dating back thousands of years, why, I have no idea.
Looking back at the previous posts (starting from #8), I think we both have talked about the same period: after last glacial period, which means current interglacial period, or Holocene in another words, i.e. period from 11 700 year ago till now. So I don't understand how were the studies I referred not relevant.
 
  • Like
Reactions: Evo
Forecasts have been very wrong before. Instead of panicking about a forecast, please provide some data that shows how much change there has been in the last 50 or 100 years. Be sure to provide data that has uncertainties, so that we all can evaluate the situation together.
 

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving

Hot Threads

Top