A new analysis of global sea level rise rates concludes the rising trend was 1.56 mm/yr−¹ from 1900-2018. This is the same rate as for 1958-2014 (1.5 mm/yr−¹), indicating there has not been a long-term distinctive change in sea level rise rates in the last 120 years.
In 2018, Frederikse et al. assessed the contributing factors to long-term sea level rise from 1958 to 2014. They determined ice melt and thermal expansion combined to add 1.3 mm/yr−¹ to sea levels during this period, and the overall rate of sea level rise was 1.5 mm/yr−¹.
Image Source: Frederikse et al., 2018
Then, in a study published last August, Frederikse et al. (2020) assessed global sea level rise rates and its sum of contributors since 1900. Interestingly, they found the rates of sea level rise were effectively the same for the entire 1900 to 2018 period (1.56 mm/yr−¹) as they were from 1958-2014 (1.5 mm/yr−¹).
The overall long-term trend in sea level rise has undergone an oscillation: high rates in the 1930s and 1940s, a slowdown during the 1960s and 1970s, and then a return to high rates in recent decades.
It’s interesting to note that the ice melt contribution to sea level rise – including the ice melt contribution from the Greenland ice sheet – was higher in the 1930s and 1940s than it has been during the last few decades. In fact, the contribution from total ice mass loss from glaciers was higher for the entire 1900-2018 period (0.70 mm/yr−¹) than it has been since 1957 (0.52 mm/yr−¹), suggesting a relative slowdown.
Neither of these trends – the multi-decadal oscillation in rates or higher ice mass contribution prior to 1950 – would appear to correlate well with the linearly accelerated rise in CO2 emissions since the 1940s.
[…] From Pierre L. Gosselin’s NoTricksZone […]
[…] From Pierre L. Gosselin’s NoTricksZone […]
I live in Melbourne Australia and am now 76 years old.
All the old piers boat ramps etc are still in the same place as they were 65 years ago, at 1.5mm per year some of these would be drowned by now.
Strangely I have seen no difference.I rarely visit the ocean and to me nothing has changed the beach is still where it was?
I used to be a luke-warm believer in global warming, but then I came across this website about 20 years ago, and whose observations on sea level were similar to yours.
http://www.john-daly.com/
As a result, I began to think about it more critically, and within the next year I was convinced AGW was probably not a thing. Since then I’ve seen no evidence that warmists are correct, and plenty that they are wrong.
Melbourne also many diverse landmarks bay and ocean and no rise in 60 years so indeed where’s the 1.5mm p.a? Land can’t be rising at every location! No Gov or Green group has a list of impacted sites let alone a well documented study of an impacted installation or landmark. They never respond including the ‘impartial’ Port of Melbourne Authority.
Can you comment on the fact that the abstract of both papers explicitly states that sea level rise has accelerated over the 20th century? That seems to be in direct contradiction to the thesis of this post.
Weekly_rise >”Can you comment on the fact that the abstract of both papers explicitly states that sea level rise has accelerated over the 20th century?”
No, not the entire 20th century. Frederikse et al (2020) states: “The acceleration in sea-level rise since the 1970s…”. So 30yrs of the 20th and 20yrs of the 21st but that is false.
Given the linear rates oscillation shown in Table 1 it is impossible for an “acceleration” in physics terms, or even an extremely loose use of the term, over the 20th century.
1970 – 2000 was a rise in linear rates (from near 0 after falling rates previous) but not a physics level “acceleration” (a term used far too loosely in the climate arena imo). Post 2000 exhibits a negative inflexion (or “deceleration” if you insist) i.e. the steep rate rise 1985 – 2000 has lessened post 2000.
The acceleration has been negative (-0.04 to -0.08 mm/yr²) since 1993.
https://www.sciencedirect.com/science/article/abs/pii/S0378383913000082
This is why using “acceleration” to describe a few decades of “trends” is so wrong.
Kenneth/Pierre, my reply to Weekly_rise went to spam trap, moderation, or just vanished.
Basically, Frederikse et al. (2020) states “since the 1970s” – not “over the 20th century”. But given Table 1 even that is false in physics terms of “acceleration”.
“the abstract of both papers explicitly states that sea level rise has accelerated over the 20th century”
Accelerations are based on starting points.
If one starts at the bottom of a sine wave, the rates have accelerated.
If one starts at the top of the sine wave, the rates have not accelerated.
If one only starts a trend at the start of a rising trend, the rates have accelerated.
If one considers the entire 120-year period and compares it to a 60-year period within that 120-year period, the overall rates are not significantly different.
Here’s a paper that says effectively the same thing as Frederikse et al. 2018 and 2020 (with higher rates, however):
https://www.sciencedirect.com/science/article/abs/pii/S0921818113002750
“The new reconstruction suggests a linear trend of 1.9 ± 0.3 mm·yr− 1 during the 20th century, with 1.8 ± 0.5 mm·yr− 1 since 1970.”
That’s why the Kennedy’s and Obama’s have seaside homesteads, they know it’s all a hoax.
Leftist politicians such as former USA president Obama and VP Gore are so concerned about rising waters they spent millions on ocean front properties. Obama has one in Martha’s Vineyard and another on the beach in Hawaii.
What a joke! Since the 1970s we have had a boat dock in Newport Beach, Southern California and the high water mark is still the same. With Biden expect to be fleeced of your hard earned money to save the Democrat party, …uh, i mean the planet..
It won’t be a Biden presidency, it will be O’Bongo’s third term.
[…] Read more at No Tricks Zone […]
I posted a link to this on my Facebook page and got slammed by their fact checkers. Interesting that they accused the papers of cherry picking.
Oh brother.
https://climatefeedback.org/claimreview/rates-of-global-sea-level-rise-have-accelerated-since-1900-contrary-to-bloggers-claims/?fbclid=IwAR0__N-6VhNgUK4639iqsNAgDTfXumXDUtaB1osK4HLZ46IwbAjxvydkYRM
[…] New Study: Sea Level Rise Rates The Same Since 1958 As They Were For All Of 1900-2018 […]