Sea Level Rise and Social Cost of Carbon

[Juan C. García]

This video can be put on several topics. Maybe Sea Level Rise is the best place to include it.

Just have a think.
NEW STUDY : Greenland is melting seven times faster than 30 years ago.

[vox_mundi]

Unusual Glacier Flow, First-Ever Look at Ice Stream Formation
https://phys.org/news/2019-12-ice-river-arctic-glacier-seas.html

Scientists have captured the birth of a high-speed ice feature for the first time on top of a Russian glacier.



In a remote archipelago of the Russian Arctic, Vavilov Ice Cap had been moving at a glacial pace for decades. Then, in 2013, it suddenly started spewing ice into the sea, flowing in what scientists call a glacial surge. But a new study suggests this surge has now become something entirely different.

The authors of the new study published in the AGU journal Geophysical Research Letters have documented what they believe is the first observation of a transition from a glacial surge to a longer-lasting flow called an ice stream.

Ice streams and glacial surges were believed to be separate phenomena driven by different mechanisms.

... if the authors of the new study are correct, glacial surges could instead be an early stage of an ice stream. If surging ice can form an ice stream on a glacier like Vavilov, then other ice caps (... Greenland, Antarctica) might also experience similar rapid ice loss

 ... "If that's true, we probably have to revise our predictions for the impact of global sea level rise in the future,"

- Whyjay Zheng, Ph.D. - lead author of the new study.

Glacial surges transport massive amounts of ice in a short amount of time, typically a few months to several years. On the other hand, ice streams can maintain a constant, rapid flow for decades to centuries.

From the time the surge at Vavilov began in 2013 until the spring of 2019, the ice cap lost 9.5 billion tons of ice, or 11 percent of the ice mass of the entire glacier basin. ...

Open Access: Whyjay Zheng et al, The Possible Transition From Glacial Surge to Ice Stream on Vavilov Ice Cap, Geophysical Research Letters (2019)

[TerryM]

^^
So much for the estimates of maximum sea level rise in a given time frame.


What does this say to the future of Miami, New Orleans and other near sea level cities?
Terry

[Tom_Mazanec]

Your Florida coastal home could lose 15% of its value by 2030 due to sea rise
And it could lose up to 35 percent of its value by 2050, according to a new report.
https://www.tampabay.com/news/real-estate/2020/01/17/your-florida-coastal-home-could-lose-15-of-its-value-by-2030-due-to-sea-rise/

In another Miami-Dade-focused report from Jupiter Intelligence, researchers found that moderate flooding of about a foot will affect nearly double the number of homes by 2050.

[gerontocrat]

I've been wandering through my files updating the odd spreadsheet here & there..

Attached are two graphs ...

NOAA Data - Sea Level & Ocean Heat Rise.png

This looks at sea level rise and increase in 0-700 metres ocean heat content. (NOAA's data for 0-2000 metres only starts in 2005).

Both tend to show an exponential increase⁽²⁾ as the years go by, with sea level rising by around 6cms over the next 10 years. Even without storms + storm surges, that's enough to make sunny-day floods in parts of Florida much more than a King Tide phenomenon.

NOAA Data - Sea Level Rise to CO2e CORRELATION
Sea Level Rise is a combination of ice sheets and glacier melt + expansion of ocean water as the oceans heat up. In the end they are the end result of increases in CO2e.

The correlation between sea level rise and CO2e is very good. R² of 0.99.

I used the NOAA figure of 496 CO2e for 2018 (and added 4 for luck for 2019). An annual increase in CO2e of 4ppm per year (say 2.7 for CO2 + 1.3 for all other gases) woud give a figure of 540 CO2e in 2030.

The correlation shown (if it held) would give a 5cm Sea Level Rise by 2030. Pretty close to the figure produced in the graph above.
_________________________________________________
⁽¹⁾ I am content with using a polynomial to project forward sea level and ocean heat content until such time we see CO2 emissions reduce, land and ocean sinks effectiveness redction reversed, and permafrost melt shown not to emit increasing amounts of greenhouse gases.

⁽²⁾I did not use the 520+ figure calculated elsewhere on the ASIF, as that wold require calculating all previous years

[nanning]

^^
Nice and interesting graphs but I think those graphs are not conveying the right information. Clearly one is a strongly delayed effect from the other. This delay is not visible.

[Sigmetnow]

Sea level rise accelerating along US coastline, scientists warn

The pace of sea level rise accelerated at nearly all measurement stations along the US coastline in 2019, with scientists warning some of the bleakest scenarios for inundation and flooding are steadily becoming more likely.

Of 32 tide-gauge stations in locations along the vast US coastline, 25 showed a clear acceleration in sea level rise last year, according to researchers at the Virginia Institute of Marine Science (Vims).

The selected measurements are from coastal locations spanning from Maine to Alaska. About 40% of the US population lives in or near coastal areas.

The gathering speed of sea level rise is evident even within the space of a year, with water levels at the 25 sites rising at a faster rate in 2019 than in 2018. ...

https://amp.theguardian.com/environment/2020/feb/03/sea-level-rise-accelerating-us-coastline-scientists-warn

[Shared Humanity]

Southeast FL is screwed.

https://www.miamiherald.com/news/local/environment/article239005633.html

Things that Florida residents can look forward to as their sewage systems fail.

https://dhss.delaware.gov/dhss/dph/files/sewagefaq.pdf

[Juan C. García]

Boston harbor brings ashore a new enemy: Rising seas
Facing climate change, Boston must gird itself for an era of rising water — or be inundated
By Steven Mufson
February 19, 2020

BOSTON — Famous for its role in America’s war for independence, this city is now fighting the rising seas.

Boston is raising streets, building berms and even requiring that new high-rise condominium developments on its harbor acquire “aqua fences” — portable metal barriers that can be dragged to the street and anchored to the pavement to deflect incoming waves.

Mayor Martin J. Walsh (D) has vowed to spend more than $30 million a year, equal to 10 percent of Boston’s five-year capital budget, to defend the city from a watery future that is expected because of climate change.

“People talk about a managed retreat” for waterfront cities, said Boston’s chief of environment, energy and open space, Christopher Cook, as he looked out on the city skyline from a popular waterside park across the harbor. “Where do we retreat to?”
…
And as climate change accelerates, the pace of sea-level rise in Boston is expected to triple, adding eight inches over 2000 levels by 2030, according to a report commissioned by the city. The ocean might climb as much as three feet above 2013 levels by 2070, the report said.

https://www.washingtonpost.com/climate-solutions/2020/02/19/boston-prepares-rising-seas-climate-change/?arc404=true

[longwalks1]

I skimmed the article to see if it mentions (if memory recalls correctly) the fact that Boston is also sinking.  I did not see.  Boston Globe article Jan 5 2018 (teaser - only a couple paragraphs and unable to cut and paste) starts out with "With its gradually sinking low lying lands"  And nothing about Dorchestor next door with the less rich mostly housing and stores. 

The key word "fighting" should be  supplanted by "losing" as the lowereing land an rising sea is supplanting Dorchestor and Boston "faster than expected."

[Shared Humanity]

The best long term strategy for coastal cities will be a managed retreat. Absent this strategy, it will be a chaotic, mismanaged retreat. Think New Orleans but on a much grander scale with more casualties.