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Climate Change: Propaganda Vs Reality

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 03 Jun 2017 22:18

It's not just the factors you mention (although you're right about all those factors), there's also rise or subsidence of the landmass itself. The Himalayas are still rising. This is a strong factor, because the data will tell you that sea level is rising in some parts of the world, but (at the same time) falling in other parts. This is relative sea level, because the land is itself not fixed.

In fact, I remember reading articles in the 1980's saying that Western Europe was dropping into the sea at a certain rate (don't remember the rate), and that at that rate the Eiffel Tower would be completely underwater in a certain number of years (don't remember how many years either).

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Re: Climate Change: Propaganda Vs Reality

Postby Amber G. » 03 Jun 2017 23:12

Nice! (Correcting the White House's 40 second Video)
https://twitter.com/francediplo_EN/stat ... 2509512704

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 04 Jun 2017 02:19

SriJoy wrote:What i am curious to find out - and the data is surprisingly hard to come by from Maharaja-Google, is what is the interaction of sedimentation rate vs global sea level rise.


Google for "silt"

Data should be available for every river - they have to keep dredging to keep them open for navigation (the larger ones).

BUT - there is no evidence that this rise has accelerated in the recent past.


I assume you mean the rise in sea levels is related to human activity? Since "accelerated" could be part of a natural cycle.

The rate of rise has been linear, and steady for 50/ 60/ 100/ 150/ (even 200 in some cases) years. In many cases, there has been a steady linear drop in sea level for equally long intervals - 50 to 200 years.


Yeah, rise and drops have occurred over time. Natural cycles.

I'm in the process of automating the whole process of skimming through all the data and estimating any change from the linear trend of rise/ fall in recent times. Will get back on this.


Looking forward.

The challenge is one of two:

Those who hypothesize that the rise is due to human activities HAVE to prove that it is not a natural cycle.

And, those who are in the opposing camp HAVE to prove that it is a natural cycle.

What is common to both is the math to estimate (this nebulous thing called) "human activities". Spend your time here ...... for it to be worth anyone's while.

Good luck.

@SriJoy,

Same for you. Silt has been there for eons. Then the question becomes, is the silting a natural cycle or does it have a "human activity" component. (Assumes that silt actually contributes to rise in sea level. I am not saying that it does.)

Finally, please make sure that you publish it on the net (not just in this thread) and let everyone beat up your findings.
Last edited by NRao on 04 Jun 2017 02:34, edited 1 time in total.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 04 Jun 2017 02:32

The sea level changes because of rising or subsiding land.
But it also rises simply because of temperature increases (positive thermal coefficient of expansion of water above 4°C).
It also rises when stores of water like in ice caps on land and glaciers melt, or inland lakes are dessicated.
Further, remember that there are ocean currents - how are they driven? think about it. The slowing down or speeding up of ocean currents means changing sea levels.

Thus e.g., for various reasons, the US east coast is seeing faster rise in sea levels than the US west coast.

PS: recent work
https://phys.org/news/2017-05-differenc ... t-sea.html
Now, an upcoming paper in Geophysical Research Letters offers the first comprehensive model for understanding differences in sea level rise along North America's East Coast. That model incorporates data not just from atmospheric pressure and ocean dynamics—changing currents, rising ocean temperatures and salinity all influence sea level—but also, for the first time, ice mass change in Greenland and Antarctica. The researchers say their model supports a growing consensus that sea level rise began accelerating in 1990 and that what they found will improve estimates of future sea level rise at a local level.


Davis said that even though the results of their modeling do support the notion that sea level rise has been accelerating over the past 25 years, that doesn't mean it will continue. "What we're seeing is big," said Davis. "But there's nothing in this paper that says, 'Oh, I've discovered acceleration and we're all going to drown now.' You can't predict forward." There are many sources of feedback in the system that scientists still don't understand, he said.

Still, Davis suggested the findings might serve as a tool for local governments. "Suppose you're a mayor in Miami and you hear that the projections for Greenland ice melt are wrong, and they're going to be much greater in the next century. You have to worry much more than if you're a mayor in Nova Scotia. But then if you're talking about ocean currents, it's flipped," said Davis. "Wherever you live, you can't just go by these [Intergovernmental Panel on Climate Change] reports that say global sea level rise is one number."
Last edited by A_Gupta on 04 Jun 2017 02:38, edited 1 time in total.

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 04 Jun 2017 02:38


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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 04 Jun 2017 03:14


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Re: Climate Change: Propaganda Vs Reality

Postby Theo_Fidel » 04 Jun 2017 03:26

Sea level rise is more related to collapse of ice sheets/blocks than the limited sedimentation we see in human times. When it happens it happens quickly and dramatically followed by long period of stability per past data.

To give folks some scale, the collapse of the Laurentide ice sheet (30 million km3) and the Fennoscondian(Siberia) (10 million km3) ice sheets over the past 10,000 years caused about 300 feet of sea level rise. Compared to that erosion sedimentation is on the order of low single digits in km3/y.

Right now there are 2 remaining blocks of ice. Iceland +/- (7 Million km3) & Antartica (30 million km3). A collapse of Greenland Ice is about 50-60 feet of rise, collapse of Antarctica is about 250 feet of rise. When it comes it will be quick and irreversible.

At least those are the projections based on past data. YMMV, all is maya, etc applies...
------------------------------

Paradoxically some models project that warming may actually trigger another ice age.

The trigger?

The ocean Conveyor (read Gulf Stream) is disrupted, cooling that part of the world by 15f. The warm tropical ocean triggers increased precipitation in the Hudson Bay area which would then reform another Laurentide Ice sheet. It would not take much. Right now that area is only snow free for about 6-8 weeks. Another 4" water or 4 feet of snow winter time precipitation would mean the snow never melts and starts reforming the Ice sheet.

End game. At least for NA & Europe.

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Re: Climate Change: Propaganda Vs Reality

Postby Amber G. » 04 Jun 2017 05:02

Image

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Re: Climate Change: Propaganda Vs Reality

Postby darshan » 04 Jun 2017 07:47

None of the Elon products are affordable enough to make any difference. For example, he sells solar roofs but there is no precondition that he will only sell you a solar roof if it is a new roof or needs replacing. I wonder how many well to do people are going to get rid of their perfectly usable roof to get his roof. Just to show off their greenness. One also wonders when looking at corporations like Google, Apple, etc. who are building new campuses how much "green" was their decisions about new buildings or products they sell and make money on. Is replacing iPhone every year pretty green? is not having ability to repair iPhone or Macbook green? Tons of laptops and electronics are junked each year due to not having universal battery replacements. is that green?

Any given day I rather back a guy going out and planting a tree than this money driven cabal lecturing about environment.

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Re: Climate Change: Propaganda Vs Reality

Postby KL Dubey » 04 Jun 2017 11:24

SriJoy wrote:^^
b) While e-cars are 'environmentally friendly' when you drive them, they are very, very dirty to produce. Just look at the process required to make e-batteries and that is the equivalent of 100,000 kms worth of gasoline emissions ! So the e-car is nothing more than 'NIMBY-ism' at its worst- it does nothing to correct the pollution levels, it just makes your immediate neighbourhood -aka the city you live in- cleaner and fresher to live in.


Those are the kinds of impacts measured in Life Cycle Analysis/Assessment. For example, this one here:

http://www.environment.ucla.edu/media/files/BatteryElectricVehicleLCA2012-rh-ptd.pdf

In terms of lifetime greenhouse emissions right from the manufacturing process, a BEV is marginally more "environmentally friendly". The "marginal" improvement is mainly because electricity generation continues to rely on fossil fuels mostly. However, that is not the fault of the BEV as such. In a future where electricity comes more from "low-carbon" sources, the BEV's "environmental friendliness" will only increase.

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 04 Jun 2017 20:35

NRao wrote:
BUT - there is no evidence that this rise has accelerated in the recent past.


I assume you mean the rise in sea levels is related to human activity? Since "accelerated" could be part of a natural cycle.



I mean that if there is any recent additional rise due to CO2, then there should be some visible *accelerating* trend in the sea level data indicating this. If the accelerating trend is there, it could be indicative of sea level rise due to increased CO2 (or it could be something else). If the accelerating trend is not there, it could mean that higher CO2 levels have had no additional effect on sea level rise (unless there is some cancelling factor). Please note that there is no dispute about the fact that the data shows sea level rise. The dispute is about whether there is any change in the rising trend in recent years, as opposed to the trend over the past 100 to 200 years.


The rate of rise has been linear, and steady for 50/ 60/ 100/ 150/ (even 200 in some cases) years. In many cases, there has been a steady linear drop in sea level for equally long intervals - 50 to 200 years.


Yeah, rise and drops have occurred over time. Natural cycles.



I'm not talking about rise and drops over past cycles. I'm talking about the currently available data, which shows sea level rises in some locations, but simultaneous drops in other locations. This has to be because of variations in land levels.


I'm in the process of automating the whole process of skimming through all the data and estimating any change from the linear trend of rise/ fall in recent times. Will get back on this.


Looking forward.

The challenge is one of two:

Those who hypothesize that the rise is due to human activities HAVE to prove that it is not a natural cycle.

And, those who are in the opposing camp HAVE to prove that it is a natural cycle.

What is common to both is the math to estimate (this nebulous thing called) "human activities". Spend your time here ...... for it to be worth anyone's while.

Good luck.


Again, it's not entirely about natural vs. man-made, it's about the specific claim that CO2 is causing this sea level rise. The observed rise over the past 100 to 200 years could also be man-made. But it's unlikely to be because of CO2, which has trended significantly upwards only over the past 50 to 60 years.

So specifically, I'm trying to see if there's any accelerated trend in the *rate* of sea level rise (or decreasing trend in the *rate* of sea level drop) over the past 50 to 60 years, which can be attributed to CO2.

So in this regard, please tell me if the following method (I don't quite like the word "methodology") sounds right to you:

* Take the available history of sea level data for any one location
* Fit a linear trend to these data (why linear? Because it seems that the sea level trends over the past 100 to 200 years have been very much linear for all the locations I've examined so far)
* Once the linear trend is done, find the LMS error between the trend and the data
* Now fit a quadratic trend to the same data and find the LMS error between the quadratic trend and the data
* If the quadratic trend has a lower LMSE than the linear trend, it means that the quadratic trend better explains the data than the linear trend
* A quadratic trend has an "acceleration" component to it, which the linear trend does not - so if the quadratic LMSE is lower than the linear LMSE, it would mean that the data itself shows an accelerating trend
* Now - assuming that the quadratic LMSE is lower than the linear LMSE - examine the direction of the acceleration in recent years
* If this direction is on the increasing side, it could indicate effects of CO2 (or something else)
* OTOH, if there is no accelerating trend visible in the data, it could indicate that either CO2 has had no effect, or that something else is cancelling out the effect of CO2

This process can be easily automated to trawl through all the data available for all the locations in the NOAA data or other available sea level data.

Is there any reason why the above analysis would not be valid?

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 04 Jun 2017 21:55

Walking backwards:

Pictorially. This is what is *happening*. Forget models. Forget historical data. Forget NOAA or any other mechanism. This is what is happening TODAY (actually as of 2013 - documented (forget the narrative in that vid - turn your audio off).





Here is *some* talk - to provide direction:

Causes of Sea Level Rise: What the Science Tells Us (2013)


And, here is a elevator quote:

The two major causes of global sea level rise are thermal expansion caused by warming of the ocean (since water expands as it warms) and increased melting of land-based ice, such as glaciers and ice sheets.


Notice there is NO mention of Co2 in that statement.



And, we have not even started a discussion on storm surges.

More l8r if needed.

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 04 Jun 2017 23:48

If this is what is happening, what should we do about it? You say there is no mention of CO2 in that statement. Does this mean curbing CO2 will not help? Or should we still curb CO2 anyway?

This is what is happening, but it has been happening for 200 years at least, and it is not happening any faster now than it was then, according to the data. Then why the alarmism, and why blame it on recent warming? Every time I ask this, I just get one more link to an article or documentary in response, saying "look look, sea level is definitely rising."

National Geographic article from 2015:

http://news.nationalgeographic.com/2015 ... l-islands/

Briefly, the article says rising sea level actually builds coral islands, not obliterates them. The sedimentation that SriJoy mentions is accelerated by rising seas and storm surges, so the side of the island that is not buffeted by storms ends up shrinking, while the other side grows. The net effect is to shift the island. But island nations such as Kiribati or Tuvalu have actually gained land, as a result of sea-level rise.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 03:50

https://www.omicsgroup.org/journals/sea ... ?aid=53459
The results show that northern portion (Ganga-Brahmaputra delta region) of the coast, mostly affected by the sea level rise (4.7 mm per year) where the Sundarban region is the most vulnerable region due to the lower elevation (ranges 0 to 20 m) and higher tidal influence. Also Visakhapatnam and Bhubaneswar have a higher rate of sea level rise respectively 0.73 and 0.43 which increase the erosional activity and probable inundation level.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 03:53

http://www.incois.gov.in/documents/ITCO ... ansen6.pdf
(PDF file)
Mean sea-level-rise along the Indian coasts
A.S. Unnikrishnan CSIR -National Institute of Oceanography, Goa

(too detailed to summarize)

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 03:58

SriJoy wrote:^^
b) While e-cars are 'environmentally friendly' when you drive them, they are very, very dirty to produce. Just look at the process required to make e-batteries and that is the equivalent of 100,000 kms worth of gasoline emissions ! So the e-car is nothing more than 'NIMBY-ism' at its worst- it does nothing to correct the pollution levels, it just makes your immediate neighbourhood -aka the city you live in- cleaner and fresher to live in.


This begs to differ:
http://shrinkthatfootprint.com/electric-cars-green

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 04:03

http://www.pnas.org/content/113/11/E1434
Temperature-driven global sea-level variability in the Common Era
We assess the relationship between temperature and global sea-level (GSL) variability over the Common Era through a statistical metaanalysis of proxy relative sea-level reconstructions and tide-gauge data. GSL rose at 0.1 ± 0.1 mm/y (2σ) over 0–700 CE. A GSL fall of 0.2 ± 0.2 mm/y over 1000–1400 CE is associated with ∼0.2 °C global mean cooling. A significant GSL acceleration began in the 19th century and yielded a 20th century rise that is extremely likely (probability P≥0.95) faster than during any of the previous 27 centuries. A semiempirical model calibrated against the GSL reconstruction indicates that, in the absence of anthropogenic climate change, it is extremely likely (P=0.95) that 20th century GSL would have risen by less than 51% of the observed 13.8±1.5 cm. The new semiempirical model largely reconciles previous differences between semiempirical 21st century GSL projections and the process model-based projections summarized in the Intergovernmental Panel on Climate Change’s Fifth Assessment Report.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 04:05

http://www.nature.com/nclimate/journal/ ... e1597.html
Hotspot of accelerated sea-level rise on the Atlantic coast of North America
Climate warming does not force sea-level rise (SLR) at the same rate everywhere. Rather, there are spatial variations of SLR superimposed on a global average rise. These variations are forced by dynamic processes arising from circulation and variations in temperature and/or salinity, and by static equilibrium processes5, arising from mass redistributions changing gravity and the Earth’s rotation and shape. These sea-level variations form unique spatial patterns, yet there are very few observations verifying predicted patterns or fingerprints. Here, we present evidence of recently accelerated SLR in a unique 1,000-km-long hotspot on the highly populated North American Atlantic coast north of Cape Hatteras and show that it is consistent with a modelled fingerprint of dynamic SLR. Between 1950–1979 and 1980–2009, SLR rate increases in this northeast hotspot were ~ 3–4 times higher than the global average. Modelled dynamic plus steric SLR by 2100 at New York City ranges with Intergovernmental Panel on Climate Change scenario from 36 to 51 cm (ref. 3); lower emission scenarios project 24–36 cm (ref. 7). Extrapolations from data herein range from 20 to 29 cm. SLR superimposed on storm surge, wave run-up and set-up will increase the vulnerability of coastal cities to flooding, and beaches and wetlands to deterioration.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 04:08

http://www.newsworks.org/index.php/loca ... level-rise
A nice article on research in progress.
This isn’t theoretical for him. The marsh has swallowed up his grandparents’ land in Maryland. His grandparents grew strawberries until the 1940s and now that land is flooded twice a day, Kirwan said.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 04:12

https://link.springer.com/article/10.10 ... 011-9119-1
There is considerable variability in the rate of rise during the twentieth century but there has been a statistically significant acceleration since 1880 and 1900 of 0.009 ± 0.003 mm year−2 and 0.009 ± 0.004 mm year−2, respectively.

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 05 Jun 2017 08:18

sudarshan wrote:If this is what is happening, what should we do about it? You say there is no mention of CO2 in that statement. Does this mean curbing CO2 will not help? Or should we still curb CO2 anyway?

This is what is happening, but it has been happening for 200 years at least, and it is not happening any faster now than it was then, according to the data. Then why the alarmism, and why blame it on recent warming? Every time I ask this, I just get one more link to an article or documentary in response, saying "look look, sea level is definitely rising."


Bhai Saheb,

You were the one who said that you disagreed with me. So, I did what would be considered the next best step: provide URLs of what other people think or have done.

National Geographic article from 2015:

http://news.nationalgeographic.com/2015 ... l-islands/

Briefly, the article says rising sea level actually builds coral islands, not obliterates them. The sedimentation that SriJoy mentions is accelerated by rising seas and storm surges, so the side of the island that is not buffeted by storms ends up shrinking, while the other side grows. The net effect is to shift the island. But island nations such as Kiribati or Tuvalu have actually gained land, as a result of sea-level rise.


Well ................................... Historically ALL such islands have always added/subtracted land mass. So, from your own link:

Image


However, based on that article (alone), it looks like the islands add/subtract in areas where humans have not intervened with modern techs - like building buildings. Also, a small observation, it seems where the sediment has added it is hardly suitable for any serious human activities. ?????


Finally, it does not tell me if human activities have or have not contributed to changes to the island/s.

Isolating "events" is a very, very, very complex task.

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 05 Jun 2017 09:00

NRao wrote:Bhai Saheb,

You were the one who said that you disagreed with me. So, I did what would be considered the next best step: provide URLs of what other people think or have done.


OK, fair enough. But why can't I get a straight answer to this question: when the data shows that the rate of sea level rise has been steady for over 100 years, maybe even 200, why is it suddenly being attributed to warming/ climate change?


Well ................................... Historically ALL such islands have always added/subtracted land mass. So, from your own link:



The article says 20% of islands have lost mass, while 80% have added mass. It doesn't mention what fraction of those islands which have added mass are inhabited, though.

However, based on that article (alone), it looks like the islands add/subtract in areas where humans have not intervened with modern techs - like building buildings. Also, a small observation, it seems where the sediment has added it is hardly suitable for any serious human activities. ?????


Finally, it does not tell me if human activities have or have not contributed to changes to the island/s.

Isolating "events" is a very, very, very complex task.


Yes, agreed, the article says man-made structures do mess up the process. The problem of islands becoming uninhabitable is due to fixed investments like buildings, water lines, electricity, etc., which can't be moved when the water comes rushing in. Also, like you said, freshly sedimented areas would probably be unsuitable for human activities for a while, maybe even a long while. But the fact remains (based on NOAA data which I've looked at so far) that the sea level rise itself seems unrelated to CO2 or what is dubbed climate change. So why keep putting this up as a poster boy for climate change, Paris accord, greenhouse gases, etc.?

A_Gupta: I saw that one link you posted, saying sea level rise has accelerated in recent times. I assume it was directed at me. I'll take a look at that also.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 18:02

http://ocean.si.edu/sea-level-rise
Smithsonian - Sea Level Rise
Key excerpts

Earth's most recent glacial period peaked about 26,500 years ago. At that time, around 10 million square miles (26 million square kilometers) of ice covered the Earth. The Laurentide ice sheet covered Canada and the American Midwest, stretching over Minnesota and Wisconsin south to New York and the Rocky Mountains. Across the Atlantic, ice blanketed Iceland and stretched down over the British Isles and northern Europe, including Germany and Poland. The Patagonian ice sheet crept north from Antarctica to cover parts of Chile and Argentina. The climate was colder and drier globally; rain was scarce, but pockets of rainforest survived in the tropics. With so much of the planet's water tied up in ice, global sea level was more than 400 feet lower than it is today.


Over the past 20,000 years or so, sea level has climbed some 400 feet (120 meters). As the climate warmed as part of a natural cycle, ice melted and glaciers retreated until ice sheets remained only at the poles and at the peaks of mountains. Early on, the sea rose rapidly, sometimes at rates greater than 10 feet (3 meters) per century, and then continued to grow in spurts of rapid sea level rise until about 7,000 years ago. Then, the climate stabilized and sea level rise slowed, holding largely steady for most of the last 2,000 years, based on records from corals and sediment cores. Now, however, sea level is on the rise again, rising faster now than it has in the past 6,000 years. The oldest tide gauges and coastal sediment preserved beneath swamps and marshes show that sea level began to rise around 1850, which is right around the time people started burning coal to propel steam engine trains, and it hasn't stopped since. The climate likely started warming as a part of a natural cycle, but the accelerated warming in the last two hundred years or so is due to a rise in atmospheric carbon dioxide. The resulting rise in sea level is likely twice what we would have seen without the increase in greenhouse gasses due to human activities.


Today, global sea level is 5-8 inches (13-20 cm) higher on average than it was in 1900. Between 1900 and 2000, global sea level rose between 0.05 inches (1.2 millimeters) and 0.07 inches (1.7 millimeters) per year on average. In the 1990s, that rate jumped to around 3.2 millimeters per year. In 2016 the rate was estimated to be 3.7 millimeters per year, and it is expected to jump higher by the end of the century.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 18:03

contd
But thanks to satellites, scientists have gotten a better handle on global sea level and how it has changed over time. Satellites take much more comprehensive measurements. In 1992, NASA launched TOPEX/Poseidon, the first of a series of satellites that measure sea level rise from space. It was followed by Jason-1 and OSTM/Jason-2, and most recently Jason-3 which was launched successfully on Jan 17, 2016. These satellites use precise radars to bounce signals off the ocean's surface to determine the height of the ocean. "The instruments are so sensitive that if they were mounted on a commercial jetliner flying at 40,000 feet, they could detect the bump caused by a dime lying flat on the ground," says Michael Freilich, Director of NASA's Earth Science program. With this information, NASA scientists calculate the average change in height almost everywhere across the globe once every 10 days.

In 2002, NASA launched the GRACE satellites, which track both ocean and ice mass by measuring changes in the Earth's gravitational field. The paired satellites orbit the Earth together and are spaced roughly 200 kilometers apart. Ice and water moving around the Earth exert different gravitational forces on the GRACE satellites. The satellites can sense the miniscule changes in the distance between one another caused by the change in gravitation force, which they measure and use to track water and ice mass change. It's thanks to GRACE that we know where the water flowing into the ocean came from. According to GRACE, melting of ice in Greenland increased sea level by 0.74 mm/year and melting in Antarctica by 0.25 mm/year since 2002.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 05 Jun 2017 18:05

contd

Although sea level is rising globally, in some places it is rising more quickly than others, and in some places sea level is even falling. This type of local- and regional-scale sea level change is what is most important when talking about the impacts of sea level on people and communities and how to plan for and manage those impacts.

Different places will experience varying consequences of sea level change for many reasons:

* Some coastal areas are positioned high above sea level—such as Scotland, Iceland, and some parts of Alaska—while others are much closer to, or even below, sea level, such as New Orleans, Louisiana and much of the eastern United States. Coasts are constantly moving and changing, with inputs from tectonic plates.
* Local geology can make land more resistant or prone to becoming saturated with encroaching seawater and eroding away.
* When ice sheets melted, a great weight was removed from some areas. To understand what has been happening since, it helps to think of a person (like an ice sheet) sitting on a mattress (the land). When the person stands up (the ice melts), the part of the mattress underneath and close to the person springs back up; but the parts of the mattress far from the person sink back down. The same rising and sinking are still happening all over the world, even thousands of years after continental ice sheets have disappeared. This is called glacial isostatic adjustment.
* Prevailing winds and ocean currents can push water towards or away from the coast.

Additional factors such as rainfall, vegetation, ice cover, groundwater extraction, coastal development, and oil and gas drilling can affect how well a region can handle rising sea levels.

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 05 Jun 2017 20:31

Just to clarify, this notion of "no recent acceleration in long term sea level rise trends" is not something I pulled out of thin air (or wherever anybody might think), when I was reading up on the subject, I read the reports of sinking islands, then just for perspective, I sought out articles from the other side. The other side of the debate consisted of several articles mentioning NOAA and other long-term tidal gauge data, with the specific claim that none of these datasets showed any visible acceleration in steady sea level rise trends over 75, 100, or 150 years. So being curious, I looked to see if these datasets were available, and indeed they were. So I took a shot a downloading them and looking at the trends myself. So far, I tend to agree with the side of the debate which says "there is no visible acceleration in long-term steady sea level rise trends."

So I'm just trying to get a satisfactory answer as to: a) does the climate-change-driven sea-level rise side of the debate disagree with what the data shows, and if so, what is their rationale? and b) if not, then why is this long-term steady sea-level rise suddenly being attributed to climate-change and a warming planet?

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Re: Climate Change: Propaganda Vs Reality

Postby Theo_Fidel » 05 Jun 2017 23:23

SriJoy wrote:Err, are you talking about sediment load ending up in the sea ?
If so, I agree.
However, my query about sediment load was the rate of sediment deposition on the deltas, leading to land being reclaimed from the sea.
While I do not know the rates for each river (hence my query), what i do know, is that the rate of land reclamation from the seas due to sedimentation, is pretty significant in some parts of the world : For example, 2000 years ago, Tamluk was the major port of Bengal. Archaeology as well as writings confirm this. Yet, Tamluk now sits 50 km from the coast, due to land reclaimed by the ganges via siltation.
Same is true in mesopotamia: sites like Ur, Eridu, etc were coastal cities 3000-4000 years ago, but now sit 200 Kms+ inland.


I don’t think that is always due to siltation.

Historically, ocean currents do the most changes to costal topography. I know for instance that the ancient S.TN port of Korkai on the Tamiparani is now about 10 km inland. ISRO has done some modeling that showed that ocean currents were that dominant culprit in moving sea shore sand from one area and depositing them in another in this area. The Tamiparani was then forced to flow further and further north. Gain in one area is balanced by loss at another.

While it is definitely possible for Ganga sediment to change the delta topography near its estuary, losses in delta areas not close to the estuary more than compensate. IIRC the Mississippi delta is losing about 10 times land area as the river is reclaiming, even at the present slow 2 feet per century rise.

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Re: Climate Change: Propaganda Vs Reality

Postby Theo_Fidel » 06 Jun 2017 00:56

SriJoy wrote:^^
The problem with this whole e-car business is two-fold:

a) We do not have enough lithium to replace even 25% of the vehicles on the road. Add in the fact that we need to re-cycle the Li batteries every 10-15 years, the actual feasible number for lithium-battery cars is ~ 5% of vehicles
b) While e-cars are 'environmentally friendly' when you drive them, they are very, very dirty to produce. Just look at the process required to make e-batteries and that is the equivalent of 100,000 kms worth of gasoline emissions ! So the e-car is nothing more than 'NIMBY-ism' at its worst- it does nothing to correct the pollution levels, it just makes your immediate neighbourhood -aka the city you live in- cleaner and fresher to live in.


I wouldn’t be so negative about the situation so early in the game.

There is more than enough lithium supply to feed both EV’s & Storage needs today and in the medium term. There are tons of mines coming online over the next few years aiming for the long term. The mantle of our planet is not short on lithium, it is a relatively common element. The question is one of viability at today’s very low costs. An entire TESLA car uses about 10 kg of lithium. Which costs about $100 mining cost and $500 in todays inflated market cost. not a lot of pricing meat there.

Manufacturing will always continue. No one sees a situation where the planet deindustrializes. And all manufacturing will remain dirty of one sort or another. Your numbers may be overly negative in this regard. Lot more can be done to clean up the process if pressure is put on manufacturers. I think cleaning up our cities first is an acceptable trade off. Best bang for buck, save the most lives, then clean up the supply chain.

There are valid reasons to criticize electric cars. I don’t think these are major ones.

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 06 Jun 2017 04:33

Sudarshan ji,

A few random thoughts.

1) Is there a reason you are not relying on the literature, on the topic, out there? This has been going on since 1965 or so

2) IF you want to reinvent the wheel, you need to know what a "wheel" is. And, the just-cannot-do-without components of a "Wheel". From the little you have posted my *impression* is that you are not familiar with the arguments being made (for or against) on the topic of Co2 and sea levels (forget rising or not). So, at a minimum, in an equation, you need "Co2" and "Sea level". I did not see it. There is really no way to assign a Co2 component to "sea level rise" by just looking at data points of "Sea level rise" - at least I have no clue how to do that, perhaps someone else can teach me

3) "Co2", is a "Green house gas". AND a very important one at that. It is one of gases that actually keep the earth warm, else that heat will escape into space

The problem arises when there is too much of it - which is what they are claiming. This "too much" then causes the various ice collections (on land)(not on bodies of water) to melt faster than usual - so the reasoning goes. Ending in "Sea level rise". (This is what you should model. How has Co2 impacted melting of ice, acidity of sea water and rise of temp of sea water)

Thsi entire cycle has been in existence since eons. The question is there "too much of Co2" and IF there is, then how much of it can be attributed to human activity.

IT is an extremely complex topic. Extreme. Which is why even the people who have spent a great deal of time modeling this are STILL open to listen to anyone.

I have extensive experience modeling at a very granular level and that was a head ache (granted we never had the computing power we have today). Building a model to capture the global aspects ........................ deserves great respect at the very least.

4) A word on NOAA.

NOAA captured, in 2013 - the last time I was involved - 17 *terabytes* of data PER DAY.

I have no clue how anyone can sit at home and model "Sea level rise", with that kind of data, at home. Note that one would need to build a model that could replicate the *GLOBAL* "Sea level rise/fall" over time, THEN address each and every "What if scenario". And, perhaps a few other things that I am missing.


5) Very seriously.

IF this were to be true - sea level rise, then it has extremely serious implication. Ones that I do not think all nations combined are in a position to address. However, that is my view.

I would rather err on the side of caution. IMHO, the side that is claiming that it does nto exist, is a hoax, etc are only out to make the rich richer. Again IMHO.

L8r

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Re: Climate Change: Propaganda Vs Reality

Postby Amber G. » 06 Jun 2017 06:02

Nrao - Thanks.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 06 Jun 2017 06:11

...none of these datasets showed any visible acceleration in steady sea level rise trends over 75, 100, or 150 years.


The claim is that there was a very small rate of rise in sea level - practically stable - for about 2000 years, and then sometime between 1850 and 1900 the rate of rise increased substantially. The seas have been rising globally at this increased rate since till the 1990s or so, when the rate of sea level rise again notched up.

Something like this:
Image


Note that 1850 is 167 years ago.
Looking for a quadratic curve is a mistaken notion, IMO. Perhaps better is trying to fit with piecewise linear curves.

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 06 Jun 2017 06:58

IMO, this is what the evidence of an acceleration in the rate of sea level rise would look like: (my blog):
http://arunsmusings.blogspot.com/2017/0 ... -rise.html

For those who don't want to click on that link, here are two plots from that blog post - of the sea level at a station in the Netherlands from 1865-1940, and 1941-2015.
Note the The first period has the sea level rising at 1.31 +/- 0.37 mm/year.
The second period has the sea level rising at 2.25 +/- 0.43 mm/year.
Note that the confidence intervals don't overlap (i.e., 1.31 + 0.37 = 1.68; 2.25 - 0.43 = 1.82).
The rate of sea level rise has increased, ergo, accelerated.

Image

Image

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 06 Jun 2017 08:18

An old topic is likely to pay us a visit.

2009 :: Cows with Gas: India's Global-Warming Problem

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 06 Jun 2017 08:36

NRao wrote:Sudarshan ji,

A few random thoughts.

2) IF you want to reinvent the wheel, you need to know what a "wheel" is. And, the just-cannot-do-without components of a "Wheel". From the little you have posted my *impression* is that you are not familiar with the arguments being made (for or against) on the topic of Co2 and sea levels (forget rising or not). So, at a minimum, in an equation, you need "Co2" and "Sea level". I did not see it. There is really no way to assign a Co2 component to "sea level rise" by just looking at data points of "Sea level rise" - at least I have no clue how to do that, perhaps someone else can teach me



There was no wheel reinvention saar, nor any attempt to assign a "CO2 component" to "sea level rise." But never mind that, I think A_Gupta got what I was getting that, and he's addressed the question I was actually raising (Thanks A_Gupta ji, I'll respond to your post in a bit).


1) Is there a reason you are not relying on the literature, on the topic, out there? This has been going on since 1965 or so



I'll go through whatever literature I can, but my query was pretty basic to begin with.


3) "Co2", is a "Green house gas". AND a very important one at that. It is one of gases that actually keep the earth warm, else that heat will escape into space

The problem arises when there is too much of it - which is what they are claiming. This "too much" then causes the various ice collections (on land)(not on bodies of water) to melt faster than usual - so the reasoning goes. Ending in "Sea level rise". (This is what you should model. How has Co2 impacted melting of ice, acidity of sea water and rise of temp of sea water)

Thsi entire cycle has been in existence since eons. The question is there "too much of Co2" and IF there is, then how much of it can be attributed to human activity.

IT is an extremely complex topic. Extreme. Which is why even the people who have spent a great deal of time modeling this are STILL open to listen to anyone.

I have extensive experience modeling at a very granular level and that was a head ache (granted we never had the computing power we have today). Building a model to capture the global aspects ........................ deserves great respect at the very least.



I can't claim anywhere near the experience you have under your belt. Having said that, I'm very familiar with the complexity involved with computer models - electrical, mechanical, or thermal. I haven't dealt with anything as complex as the entire global climate system, but I've dealt with bits and pieces of the building blocks which go into climate models. Even the radiative forcing function is a bear to deal with, just by itself. The computing power needed to deal with this in an exact line-by-line sense was hard to come by even in the early 2000's - I don't know about developments after that. Which is why, though I do have a great deal of respect for the task of building the global climate model, I'm also skeptical that it can even be done with current knowledge. That's why I was trying to devise simple sanity checks, and hoping somebody would address basic queries to guide me, so I could gauge the level of sophistication of the models that the professionals were building.

So with that in mind, here's a question for you, just out of curiosity. What kind of radiative forcing function is used in these global climate models? Do the computations go line-by-line (which would be ideal), or are band models used instead?


4) A word on NOAA.

NOAA captured, in 2013 - the last time I was involved - 17 *terabytes* of data PER DAY.

I have no clue how anyone can sit at home and model "Sea level rise", with that kind of data, at home. Note that one would need to build a model that could replicate the *GLOBAL* "Sea level rise/fall" over time, THEN address each and every "What if scenario". And, perhaps a few other things that I am missing.



Serious question, no sarcasm involved - are all these data actually fed into the models for verification or validation?

Again, the dataset I downloaded was minimal, but should have been representative. And again, with all due respect, I think you misunderstood what I was actually trying out or what I was asking.


5) Very seriously.

IF this were to be true - sea level rise, then it has extremely serious implication. Ones that I do not think all nations combined are in a position to address. However, that is my view.

I would rather err on the side of caution. IMHO, the side that is claiming that it does nto exist, is a hoax, etc are only out to make the rich richer. Again IMHO.

L8r


See saar, after all the clarifications I made in multiple posts saying there was no doubt in my mind about the sea level rise itself, just a basic query about the *rate* of rise, you still say this. I don't know if this was a general statement against the so called "deniers," or about me.

I think I got some direction from A_Gupta saar, so I'm happy with that for now. Peace, and no offense. I think we were both just talking past each other. I much appreciate your detailed response, in any case.

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Re: Climate Change: Propaganda Vs Reality

Postby sudarshan » 06 Jun 2017 08:46

A_Gupta wrote:
...none of these datasets showed any visible acceleration in steady sea level rise trends over 75, 100, or 150 years.


The claim is that there was a very small rate of rise in sea level - practically stable - for about 2000 years, and then sometime between 1850 and 1900 the rate of rise increased substantially. The seas have been rising globally at this increased rate since till the 1990s or so, when the rate of sea level rise again notched up.

Something like this:
Image


Note that 1850 is 167 years ago.
Looking for a quadratic curve is a mistaken notion, IMO. Perhaps better is trying to fit with piecewise linear curves.


Thanks, this is the kind of response I was hoping for.

If you can fit it with piecewise linear curves, a quadratic would still do a decent job of showing the acceleration trend, right?

IMO, this is what the evidence of an acceleration in the rate of sea level rise would look like: (my blog):
http://arunsmusings.blogspot.com/2017/0 ... -rise.html

For those who don't want to click on that link, here are two plots from that blog post - of the sea level at a station in the Netherlands from 1865-1940, and 1941-2015.
Note the The first period has the sea level rising at 1.31 +/- 0.37 mm/year.
The second period has the sea level rising at 2.25 +/- 0.43 mm/year.
Note that the confidence intervals don't overlap (i.e., 1.31 + 0.37 = 1.68; 2.25 - 0.43 = 1.82).
The rate of sea level rise has increased, ergo, accelerated.


Again, this is what I was asking to begin with, so thanks. Now my query is - where are these claims of 1 to 2 meters of sea level rise per century coming from? The global average sea level rise rate currently seems to be about 3.2 mm/year. This translates to 320 mm, or about a foot per century. Add to that the acceleration component you mentioned before - 0.009+/-0.003 mm/year^2. So with the higher estimate - 0.012 mm/year^2 - per century, with 0.5*a*t^2, this will add another 60 mm of rise, so 380 mm or less than 0.4 m per century. So why the hysteria about catastrophic rise? Are the claims of meters of sea level rise simply coming from computer model predictions?

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 06 Jun 2017 17:14

sudarshan wrote:If you can fit it with piecewise linear curves, a quadratic would still do a decent job of showing the acceleration trend, right?


If you assume that the acceleration is a constant.


Now my query is - where are these claims of 1 to 2 meters of sea level rise per century coming from?


Most of the sea level rise depends on what you predict for the fates of the Greenland and Antarctic ice sheets.
Last edited by A_Gupta on 06 Jun 2017 17:35, edited 2 times in total.

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 06 Jun 2017 17:26

Try these.

Understanding Sea Level

The following has some meat. You can get an idea of the complexities of both modeling and then projection.

Projections

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 06 Jun 2017 17:33

The world ocean area is around 362 million square kilometers or 362 * 10^12 square meters. A one centimeter rise in ocean levels corresponds to 3.62 * 10^12 cubic meters of water.

Greenland contains 2850 * 10^12 cubic meters of ice.
A net loss of 1% of its ice will mean, very approximately, an ocean rise of around 7 centimeters.

The Antarctic contains ten times as much ice as Greenland.

Greenland is currently losing an estimated 0.27 * 10^12 tons per year.
(http://www.sciencemag.org/news/2017/02/ ... d-meltdown)
Also see here for the Greenland ice mass balance:
http://beta.dmi.dk/en/groenland/maaling ... ss-budget/

Will the rate of ice loss increase as global temperatures rise? That is the multi-billion-dollar question.

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Re: Climate Change: Propaganda Vs Reality

Postby NRao » 06 Jun 2017 18:20

Will the rate of ice loss increase as global temperatures rise? That is the multi-billion-dollar question.


Is it?

Or is the question how much of that "global temperatures rise" is due to human activities? For IF the temp rise is natural, something cyclical, then there should be no corrective action humans could or should take.

?????

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Re: Climate Change: Propaganda Vs Reality

Postby A_Gupta » 06 Jun 2017 20:37

NRao wrote:
Will the rate of ice loss increase as global temperatures rise? That is the multi-billion-dollar question.


Is it?

Or is the question how much of that "global temperatures rise" is due to human activities? For IF the temp rise is natural, something cyclical, then there should be no corrective action humans could or should take.

?????


1. Whatever the cause, if enough land ice melts to raise the average sea level by a meter in the space of eighty years, the effects on the global economy will be huge and negative.

One should also consider what will happen to the rivers of North India, if e.g., the Himalayan glaciers are depleted.

2. The cause, almost certainly, is due to human activities, and hence can be mitigated. One thing to note is that natural processes in the geological record are typically much slower. AFAIK, the abrupt changes in climate found in the geological record happened over centuries, not decades.

3. If you accept that the Earth has entered the Anthropocene, i.e., the era when human activities have significant impact on geology, then even potential disasters caused by natural, non-human processes can potentially be mitigated. E.g., asteroid impact avoidance. E.g., google/bing "geoengineering". One big issue with such approaches is, I think, that of unintended consequences.


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