5 ms·

Sea level much higher than assumed in most coastal hazard assessments

107 points by jacquesm 8mo ago

pjmlp 8mo ago
We just started another war with unforeseen consequences to the planet, while destroying all resources to feed the AI monster, forget about all those paper straws.
bikenaga 8mo ago
[flagged]
- buildsjets 8mo ago
  The only thing you ever post is AI summaries of articles. Why?
  - Schiendelman 8mo ago
    I assume that's a bot that helps us not have to click on articles for basic information. Personally, I find it quite useful. I'd love to have that built into HN.
    - solid_fuel 8mo ago
      I think every browser has an AI summary feature now, if you find reading and engaging with information just too difficult and challenging.
      - Schiendelman 8mo ago
        Please don't engage like this, it's not appropriate on HN. If you're curious about why such a summary might be useful to someone, ask!
- MisterTea 8mo ago
  We are more than capable of reading thanks.
deleted 8mo ago
[deleted]
sebmellen 8mo ago
The saddest part of global turmoil around AI, Iran war, etc. is how dramatically climate change has disappeared from the 'global conversation'. This is not something we can afford to ignore for much longer.
- quotemstr 8mo ago
  [flagged]
  - sebmellen 8mo ago
    "People have been saying computers will start to speak since the Dartmouth Workshop in 1956. Here we are 50 years later in 2006 and there's no sign of progress yet! Nothing's happened. You really need to knock if off with the predictions."
    - quotemstr 8mo ago
      [flagged]
      - jbotz 8mo ago
        > Has the climate collapsed? There are still glaciers in Glacier Nation Park. The Maldives remain islands, not seamounts. Just to really quickly call out these tired old straw-men... all of these "predicted disasters" are far further along today than they were predicted to be by this date by, for example, the IPCC in 1990[0]. Deniers keep acting as if it scientists have been "crying wolf" for decades when the truth is that the 99% of the scientists doing real work on anthropogenic global warming have always been extremely conservative and reality has outpaced their predictions all along. [0] https://www.ipcc.ch/report/ar1/wg2/ https://www.ipcc.ch/report/ar1/wg2/
      - tokai 8mo ago
        The glaciers in Glacier Nation Park have reduced by 39% the last 50 years. There used to be 150 glaciers larger than 25 acres, now there is 26. Maybe not the best example. https://www.usgs.gov/news/national-news-release/glaciers-rapidly-shrinking-and-disappearing-50-years-glacier-change https://www.usgs.gov/news/national-news-release/glaciers-rap...
metalman 8mo ago
Watch your warming oceans expand in real time here https://nsidc.org/sea-ice-today https://nsidc.org/sea-ice-today above shows what may be the earliest ever peak sea ice and https://www.ospo.noaa.gov/products/ocean/sst/contour/ https://www.ospo.noaa.gov/products/ocean/sst/contour/ and the one above is absolutly terrifying , or should be to wanabe hegemnons thinking that the naritive, is thiers.
- lazyasciiart 8mo ago
  Can you explain what background knowledge I need to be terrified looking at the second one?
  - metalman 8mo ago
    it is a tool that shows daily snap shots of the SST to use it you need to have a good grasp on geography/oceanography, and then spen a bit of time each day looking at it, and cross corelating with things like hurricanes, to see the trace spiral of cooler water that a giant storm will imprint into the oceans surface, or this year, the very significant chanhes in the worlds major hot and cold currents, and size of the spill over from the south wester pacific into the atlantic.
- bvdw 8mo ago
  The first link contains a banner that perfectly illustrates the tragic moment we're in: "Due to non-renewed funding, several Sea Ice Today tools and services are now suspended or reduced."
- sebmellen 8mo ago
  So we are more than 1 million square kilometers lower than our record minimum year of 2012. Holy shit. https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-interactive-sea-ice-graph https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-inter...
  - jacquesm 8mo ago
    https://www.theclimatebrink.com/p/the-scariest-climate-plot-in-the https://www.theclimatebrink.com/p/the-scariest-climate-plot-...
measurablefunc 8mo ago
In almost every fictional story¹ dealing w/ near future outcomes every author just assumes that Miami & New York are under water. ¹https://en.wikipedia.org/wiki/The_Ministry_for_the_Future https://en.wikipedia.org/wiki/The_Ministry_for_the_Future
cadamsdotcom 8mo ago
[flagged]
mmooss 8mo ago
> ... 90% of the hazard assessments assume coastal sea levels based on geoid models, rather than using actual sea-level measurements. > A geoid is an equipotential surface model that approximates MSL based on gravity and the rotation of Earth. As geoid quality depends on gravity observations, uncertainties in global geoid models can range up to several metres in regions that suffer from gravitational data paucity ..., predominantly located in the Global South. Moreover, actual sea-surface height is not just determined by the gravity and rotation of Earth, but also by, for example, ocean currents and large-scale circulation, winds, tides, seawater temperature and salinity. As a result, time-average sea-surface height can deviate strongly (up to several metres) from a geoid, and its difference is the so-called mean dynamic topography (MDT). I don't quite grasp how those flaws in geoid models lead to an overall significant underestimation of sea-level. Shouldn't all those average out? > uncertainties in global geoid models Why would those tend toward underestimation? > sea-surface height is not just determined by the gravity and rotation of Earth, but also by, for example, ocean currents and large-scale circulation, winds, tides, seawater temperature and salinity. Other than temperature and maybe salinity, those factors move water in a closed system: increasing water one place reduces it in another (?). > time-average sea-surface height can deviate strongly Why would average deviation by positive and not zero or negative?
fred_is_fred 8mo ago
Over the past 5 or so years, I've seen population projections missed over and over. Growth is slowing and it's slowing faster than projected. Almost every projection is too high. Does that have any impact on climate change rates? Or is it a wash because societies with shrinking populations are using more resources? I've not been able to find much research here.

107 points by jacquesm 8mo ago

pjmlp 8mo ago

We just started another war with unforeseen consequences to the planet, while destroying all resources to feed the AI monster, forget about all those paper straws.

bikenaga 8mo ago

[flagged]

buildsjets 8mo ago
The only thing you ever post is AI summaries of articles. Why?
- Schiendelman 8mo ago
  I assume that's a bot that helps us not have to click on articles for basic information. Personally, I find it quite useful. I'd love to have that built into HN.
  - solid_fuel 8mo ago
    I think every browser has an AI summary feature now, if you find reading and engaging with information just too difficult and challenging.
    - Schiendelman 8mo ago
      Please don't engage like this, it's not appropriate on HN. If you're curious about why such a summary might be useful to someone, ask!
MisterTea 8mo ago
We are more than capable of reading thanks.

deleted 8mo ago

[deleted]

sebmellen 8mo ago

The saddest part of global turmoil around AI, Iran war, etc. is how dramatically climate change has disappeared from the 'global conversation'. This is not something we can afford to ignore for much longer.

quotemstr 8mo ago
[flagged]
- sebmellen 8mo ago
  "People have been saying computers will start to speak since the Dartmouth Workshop in 1956. Here we are 50 years later in 2006 and there's no sign of progress yet! Nothing's happened. You really need to knock if off with the predictions."
  - quotemstr 8mo ago
    [flagged]
    - jbotz 8mo ago
      > Has the climate collapsed? There are still glaciers in Glacier Nation Park. The Maldives remain islands, not seamounts. Just to really quickly call out these tired old straw-men... all of these "predicted disasters" are far further along today than they were predicted to be by this date by, for example, the IPCC in 1990[0]. Deniers keep acting as if it scientists have been "crying wolf" for decades when the truth is that the 99% of the scientists doing real work on anthropogenic global warming have always been extremely conservative and reality has outpaced their predictions all along. [0] https://www.ipcc.ch/report/ar1/wg2/ https://www.ipcc.ch/report/ar1/wg2/
    - tokai 8mo ago
      The glaciers in Glacier Nation Park have reduced by 39% the last 50 years. There used to be 150 glaciers larger than 25 acres, now there is 26. Maybe not the best example. https://www.usgs.gov/news/national-news-release/glaciers-rapidly-shrinking-and-disappearing-50-years-glacier-change https://www.usgs.gov/news/national-news-release/glaciers-rap...

metalman 8mo ago

Watch your warming oceans expand in real time here https://nsidc.org/sea-ice-today https://nsidc.org/sea-ice-today above shows what may be the earliest ever peak sea ice and https://www.ospo.noaa.gov/products/ocean/sst/contour/ https://www.ospo.noaa.gov/products/ocean/sst/contour/ and the one above is absolutly terrifying , or should be to wanabe hegemnons thinking that the naritive, is thiers.

lazyasciiart 8mo ago
Can you explain what background knowledge I need to be terrified looking at the second one?
- metalman 8mo ago
  it is a tool that shows daily snap shots of the SST to use it you need to have a good grasp on geography/oceanography, and then spen a bit of time each day looking at it, and cross corelating with things like hurricanes, to see the trace spiral of cooler water that a giant storm will imprint into the oceans surface, or this year, the very significant chanhes in the worlds major hot and cold currents, and size of the spill over from the south wester pacific into the atlantic.
bvdw 8mo ago
The first link contains a banner that perfectly illustrates the tragic moment we're in: "Due to non-renewed funding, several Sea Ice Today tools and services are now suspended or reduced."
sebmellen 8mo ago
So we are more than 1 million square kilometers lower than our record minimum year of 2012. Holy shit. https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-interactive-sea-ice-graph https://nsidc.org/sea-ice-today/sea-ice-tools/charctic-inter...
- jacquesm 8mo ago
  https://www.theclimatebrink.com/p/the-scariest-climate-plot-in-the https://www.theclimatebrink.com/p/the-scariest-climate-plot-...

measurablefunc 8mo ago

In almost every fictional story¹ dealing w/ near future outcomes every author just assumes that Miami & New York are under water. ¹https://en.wikipedia.org/wiki/The_Ministry_for_the_Future https://en.wikipedia.org/wiki/The_Ministry_for_the_Future

cadamsdotcom 8mo ago

[flagged]

mmooss 8mo ago

> ... 90% of the hazard assessments assume coastal sea levels based on geoid models, rather than using actual sea-level measurements. > A geoid is an equipotential surface model that approximates MSL based on gravity and the rotation of Earth. As geoid quality depends on gravity observations, uncertainties in global geoid models can range up to several metres in regions that suffer from gravitational data paucity ..., predominantly located in the Global South. Moreover, actual sea-surface height is not just determined by the gravity and rotation of Earth, but also by, for example, ocean currents and large-scale circulation, winds, tides, seawater temperature and salinity. As a result, time-average sea-surface height can deviate strongly (up to several metres) from a geoid, and its difference is the so-called mean dynamic topography (MDT). I don't quite grasp how those flaws in geoid models lead to an overall significant underestimation of sea-level. Shouldn't all those average out? > uncertainties in global geoid models Why would those tend toward underestimation? > sea-surface height is not just determined by the gravity and rotation of Earth, but also by, for example, ocean currents and large-scale circulation, winds, tides, seawater temperature and salinity. Other than temperature and maybe salinity, those factors move water in a closed system: increasing water one place reduces it in another (?). > time-average sea-surface height can deviate strongly Why would average deviation by positive and not zero or negative?

fred_is_fred 8mo ago

Over the past 5 or so years, I've seen population projections missed over and over. Growth is slowing and it's slowing faster than projected. Almost every projection is too high. Does that have any impact on climate change rates? Or is it a wash because societies with shrinking populations are using more resources? I've not been able to find much research here.