Climate talks fail
SoloSailor wrote:
Bravo5150 wrote:
Why are Solo and cyberdad arguing? The graphs seem to support the point cyberdad is trying to make with my interpretation of them.
Quite the opposite. Cyberdad has been making the claim that south sea islands are flooding due to rising ocean levels. Data taken at various locations around the islands (shown in the graphs) shows that sea levels have actually been dropping since sometime in 2007.
According to my interpretation of the graphs, they say they are showing a decline in height of the land mass, measured in meters above sea level. According to what I am reading it means either some serious erosion is going on or sea level has risen for the height of the land mass to be going down.
Bravo5150 wrote:
According to my interpretation of the graphs, they say they are showing a decline in height of the land mass, measured in meters above sea level. According to what I am reading it means either some serious erosion is going on or sea level has risen for the height of the land mass to be going down.
Explanation from the source:
Quote:
The results below provide the ellipsoidal height of the tide gauge sensor benchmark (black squares) on the dates that levelling surveys were undertaken. Superimposed is the GNSS time series (grey). This has been done to show that in the majority of cases the change in height of the tide gauge is directly correlated to the movement of the GNSS station (implying the land mass under both the GNSS site and tide gauges are moving at almost the same rate). This is not true for all sites (e.g. Tonga), where they are not aligned. In these cases, localised movement at the tide gauge site may be the cause (e.g. the Tonga tide gauge has been hit by boats and its position has moved). NOTE: The vertical scale of the plots have been altered to show variability of the ellipsoidal height from the mean tide gauge sensor benchmark ellipsoidal height.
IOW, land/water seem to be maintaining equilibrium.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
Bravo5150 wrote:
So, are you saying it is measuring tide height and not landmass height?
Yes. The solid line is tide height (buoys) and the small squares are land based GPS benchmarks.
It's almost 3:00am and Captchas are pissing me off. Calling it quits for now.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
Last one for tonight:
I was wrong about the measurements being taken from buoys.
This is the setup being used:
Quote:
Measuring absolute sea level variation
In most cases, three types of measurement are necessary to assess whether absolute sea level is changing at a given point: tide gauge data, GNSS data and levelling observations.
Tide gauges measure relative sea level variation, i.e. how sea level changes relative to a tide gauge attached to a rock wall or wharf. It is important to note a tide gauge cannot differentiate between changes in the sea level and movement of the tide gauge if the land it is attached to moves.
GNSS can be used to measure the vertical crustal motion of the Earth with respect to the centre of the Earth. It is a useful technique to distinguish relative sea level rise from absolute sea level rise. For example, in the case of the tide gauge subsiding, if the land subsidence has been observed by GNSS on the tide gauge, this trend can be removed from the relative sea level variation and an estimate of absolute sea level change can be derived.
In situations where a GNSS station is not attached directly to the tide gauge, in order to distinguish sea level variation from vertical crustal movement, it is necessary to regularly measure the height difference between the GNSS station and the tide gauge.
Absolute movement of the tide gauge
As part of the PSLGM Project, the difference in height between the GNSS station and tide gauge sensor benchmark is measured by levelling between them every 18 months (Figure 2). by staff from the Pacific Community (previously the Secretariat of the Pacific Community). The difference in height is added to the GNSS ellipsoidal height at the time of the levelling survey to compute the ellipsoidal height of the tide gauge sensor benchmark.
In most cases, three types of measurement are necessary to assess whether absolute sea level is changing at a given point: tide gauge data, GNSS data and levelling observations.
Tide gauges measure relative sea level variation, i.e. how sea level changes relative to a tide gauge attached to a rock wall or wharf. It is important to note a tide gauge cannot differentiate between changes in the sea level and movement of the tide gauge if the land it is attached to moves.
GNSS can be used to measure the vertical crustal motion of the Earth with respect to the centre of the Earth. It is a useful technique to distinguish relative sea level rise from absolute sea level rise. For example, in the case of the tide gauge subsiding, if the land subsidence has been observed by GNSS on the tide gauge, this trend can be removed from the relative sea level variation and an estimate of absolute sea level change can be derived.
In situations where a GNSS station is not attached directly to the tide gauge, in order to distinguish sea level variation from vertical crustal movement, it is necessary to regularly measure the height difference between the GNSS station and the tide gauge.
Absolute movement of the tide gauge
As part of the PSLGM Project, the difference in height between the GNSS station and tide gauge sensor benchmark is measured by levelling between them every 18 months (Figure 2). by staff from the Pacific Community (previously the Secretariat of the Pacific Community). The difference in height is added to the GNSS ellipsoidal height at the time of the levelling survey to compute the ellipsoidal height of the tide gauge sensor benchmark.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
kokopelli
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Bravo5150 wrote:
SoloSailor wrote:
Bravo5150 wrote:
Why are Solo and cyberdad arguing? The graphs seem to support the point cyberdad is trying to make with my interpretation of them.
Quite the opposite. Cyberdad has been making the claim that south sea islands are flooding due to rising ocean levels. Data taken at various locations around the islands (shown in the graphs) shows that sea levels have actually been dropping since sometime in 2007.
According to my interpretation of the graphs, they say they are showing a decline in height of the land mass, measured in meters above sea level. According to what I am reading it means either some serious erosion is going on or sea level has risen for the height of the land mass to be going down.
How about subsidence? It is quite common in some places as a result of pumping out the ground water.
There is also an issue with glacial rebound in some places that can make sea level appear to fall on one portion of a plate while appearing to rise on another.
kokopelli wrote:
Bravo5150 wrote:
SoloSailor wrote:
Bravo5150 wrote:
Why are Solo and cyberdad arguing? The graphs seem to support the point cyberdad is trying to make with my interpretation of them.
Quite the opposite. Cyberdad has been making the claim that south sea islands are flooding due to rising ocean levels. Data taken at various locations around the islands (shown in the graphs) shows that sea levels have actually been dropping since sometime in 2007.
According to my interpretation of the graphs, they say they are showing a decline in height of the land mass, measured in meters above sea level. According to what I am reading it means either some serious erosion is going on or sea level has risen for the height of the land mass to be going down.
How about subsidence? It is quite common in some places as a result of pumping out the ground water.
There is also an issue with glacial rebound in some places that can make sea level appear to fall on one portion of a plate while appearing to rise on another.
Yeah, I'm not sure what's going on here. It would be interesting to hear about the adjustments scientists make when they average these in order to account for things like differences among the sites and the kind of factors you mention, kokopelli.
There was a lot of discussion about similar adjustments to the temp record a few years back, with denialists saying, See, they make adjustments? Just that alone means they were lying and scamming us all! What they failed to understand was that the adjustments actually ended up lowering the temperature rise below what it would otherwise say, and it was to account for things like urban heat islands and various other station-specific changes. This was pretty remarkable to me, because a few years before that the denialists were complaining about how urban heat islands and other factors were not being taken into account when in fact the scientists had been taking them into account all along. This switch of tactic among denialists had a profound effect on me, and I realized that the scientists were most likely taking into account things they needed to do to ensure their temperature record was as sound as it could be. This shows the importance of scientific collaboration.
_________________
"You have a responsibility to consider all sides of a problem and a responsibility to make a judgment and a responsibility to care for all involved." --Ian Danskin
It looks like this past decade was the warmest on record, and now Antarctica which until now had avoided much of the ice melt hit a new record for ice melt:
https://www.newsweek.com/record-hit-ice ... ssion=true
_________________
"You have a responsibility to consider all sides of a problem and a responsibility to make a judgment and a responsibility to care for all involved." --Ian Danskin
kokapelli wrote:
How about subsidence? It is quite common in some places as a result of pumping out the ground water.
There is also an issue with glacial rebound in some places that can make sea level appear to fall on one portion of a plate while appearing to rise on another.
There is also an issue with glacial rebound in some places that can make sea level appear to fall on one portion of a plate while appearing to rise on another.
AFAIK, glacial rebound isn't an issue here, but excessive ground water depletion due to increasing populations and a rapidly expanding tourism industry is a definite concern in some (most?) of these areas. Volcanism and earthquakes are also a contributors- particularly in Samoa and PNG. These are known factors that have been taken into account when gathering measurements and assessing the sea level data.
The evidence so far seems to indicate that land subsidence is likely the primary culprit for any increased flooding that may be occurring in these areas. Contrary to claims made by cyberdad (which is what set off this part of the discussion) sea level rise due to man made global warming doesn't seem to be a factor.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
beneficii wrote:
..denialists were complaining...with denialists saying.. among denialists..
Just something to keep in mind:
The constant use of 'denialist' as a means of dismissing those who don't agree with you is far more likely to be viewed as desperately defending a cherished belief as opposed to genuinely seeking rational inquiry.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
SoloSailor wrote:
beneficii wrote:
..denialists were complaining...with denialists saying.. among denialists..
Just something to keep in mind:
The constant use of 'denialist' as a means of dismissing those who don't agree with you is far more likely to be viewed as desperately defending a cherished belief as opposed to genuinely seeking rational inquiry.
They weren’t “genuinely seeking rational inquiry”, they were looking to play “gotcha” with the scientists. Otherwise, how can you go from “You need to account for the urban heat island effect” to “You’re adjusting for the urban heat island effect? OMG, you’re cooking the books!” I used to be sympathetic to them, but not anymore after that.
And you are not calmly seeking rational inquiry, given your rant a couple pages back (in an image no less) about “compulsive liars” and the “truth”. People who rant about that in science discussions send up red flags for me.
_________________
"You have a responsibility to consider all sides of a problem and a responsibility to make a judgment and a responsibility to care for all involved." --Ian Danskin
SoloSailor wrote:
Just something to keep in mind:
The constant use of 'denialist' as a means of dismissing those who don't agree with you is far more likely to be viewed as desperately defending a cherished belief as opposed to genuinely seeking rational inquiry.
The constant use of 'denialist' as a means of dismissing those who don't agree with you is far more likely to be viewed as desperately defending a cherished belief as opposed to genuinely seeking rational inquiry.
I do not understand this type of approach which I see going around the internet, from those whom I assume want to win others over to help save the planet. Even if they feel they are not going to convince whoever they are talking too, they still have an audience.
EzraS wrote:
I do not understand this type of approach which I see going around the internet, from those whom I assume want to win others over to help save the planet. Even if they feel they are not going to convince whoever they are talking too, they still have an audience.
It's an appeal to emotion.
The goal is to preemptively discredit anyone who might present an opposing argument.
(As well as invoking an us vs them mentality.)
The Appeal to Emotion: Persuasion Through Feelings Rather than Facts
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
The process of making adjustments like this is called homogenization. There are a lot of inhomogenities that can arise in the temperature record, the urban heat island effect being the most well-known. As this website mentions:
Quote:
There has been much discussion of temperature adjustment of late in both climate blogs and in the media, but not much background on what specific adjustments are being made, why they are being made, and what effects they have. Adjustments have a big effect on temperature trends in the U.S., and a modest effect on global land trends. The large contribution of adjustments to century-scale U.S. temperature trends lends itself to an unfortunate narrative that “government bureaucrats are cooking the books”.
Having worked with many of the scientists in question, I can say with certainty that there is no grand conspiracy to artificially warm the earth; rather, scientists are doing their best to interpret large datasets with numerous biases such as station moves, instrument changes, time of observation changes, urban heat island biases, and other so-called inhomogenities that have occurred over the last 150 years. Their methods may not be perfect, and are certainly not immune from critical analysis, but that critical analysis should start out from a position of assuming good faith and with an understanding of what exactly has been done.
Having worked with many of the scientists in question, I can say with certainty that there is no grand conspiracy to artificially warm the earth; rather, scientists are doing their best to interpret large datasets with numerous biases such as station moves, instrument changes, time of observation changes, urban heat island biases, and other so-called inhomogenities that have occurred over the last 150 years. Their methods may not be perfect, and are certainly not immune from critical analysis, but that critical analysis should start out from a position of assuming good faith and with an understanding of what exactly has been done.
http://berkeleyearth.org/understanding- ... ture-data/
The problem with who I call the denialists is they start out assuming bad faith on the part of the scientists. They pretty much never take up their concerns with the scientists involved, and instead always go to the lay public to "expose" the scientists, even though the lay public doesn't really know very much about the process anyway. Which is unfortunate, because you can dispute how it's being done, but you should understand that scientists are doing the best they can to get an accurate read of how the temperature has been changing. When you have people ranting about taking down the "liars" in the scientific community, and mentioning how they are the ones with the "truth", it's just not very productive at all. But this is just what the oil companies want: They want to sow distrust and doubt among the public about the science so they can continue to make massive profits in the short-term.
_________________
"You have a responsibility to consider all sides of a problem and a responsibility to make a judgment and a responsibility to care for all involved." --Ian Danskin
SoloSailor wrote:
EzraS wrote:
I do not understand this type of approach which I see going around the internet, from those whom I assume want to win others over to help save the planet. Even if they feel they are not going to convince whoever they are talking too, they still have an audience.
It's an appeal to emotion.
The goal is to preemptively discredit anyone who might present an opposing argument.
(As well as invoking an us vs them mentality.)
The Appeal to Emotion: Persuasion Through Feelings Rather than Facts
That's not conducive towards a discussion about science, and why it tends to take on religious overtones. There are times when I feel like Christopher Hitchens talking to religious fundamentalists.
EzraS wrote:
That's not conducive towards a discussion about science, and why it tends to take on religious overtones. There are times when I feel like Christopher Hitchens talking to religious fundamentalists.
Yep. Cults (such as Scientology) are renowned for using this technique as a method of both deflecting criticism and keeping their followers in line.
_________________
Without deviation from the norm progress is not possible.
-Frank Zappa
