Honest global warming chart Blog: U.K. (and global) sea level rise shows no acceleration from global warming

NOTE:

No SINGLE tide gauge time series data have to match the trend in global mean eustatic sea level. That's why I added links to 19 more long-term NOAA tide gauges at the end of this article. Pick a few at random, and try to find acceleration of sea level rise that might be caused by global warming. You won't find that in any of the 19 tide gauges.

Sea level rise is the parameter that all skeptics of climate alarmism should concentrate on. It aggregates the melting of ice crystals all over the planet into one easy to understood measure of change in retained energy of the surface of our planet. The climate alarmists do understand this.

In their headline articles. NOAA splice the new satellite record onto the sea level gauges from 1993 onwards, to claim ‘acceleration’ of ice melt. It’s comparing apples and oranges, because the satellites measure the entire sea surface, therefore measuring a greater depth of warming water which likely expands more than the shallow waters of the coast. Not science, just propaganda manipulation of those who think a satellite is bound to be ‘better’ than a float gauge. Satellites, in fact, are an order of magnitude less sensitive, and much more prone to been error for very distant measurements of a few millimeters every year ... of a constantly moving ocean surface!

The absence of an acceleration in the rate of sea level rise pre and post industrial revolution in the long term gauges, is our answer -- no change in acceleration = no sea level response to CO2. Despite rising CO2 levels, sea level rise, in progress for 20,000 years, has not accelerated.

Sea level has been rising for about 20,000 years, as glaciers on land melted. The North American land glaciers are shown in the first chart below. The total sea level rise so far is about 120 meters, or 400 feet, as shown in the second chart below. Much slower sea level rise in the past few centuries, with no sign of acceleration from global warming:

The overall average sea level rise rate, in the Newlyn and North Shields, UK tide gauge charts shown below, is a harmless +2mm a year. Newlyn and North Shields are the two main long term tidal gauge sites in the UK (data from NOAA, US Commerce Department):

In the UK tide gauge charts, you can see a steady rise with large monthly variations, but no acceleration of sea level rise from global arming after 1975. North Shields only has full data up to 2017, so 2008-17 is used as the current decade there in the charts below.

Sea levels fell in the middle of the last century, earlier in North Shields than in Newlyn, for no obvious reason.

The decade to decade charts below show Newlyn with a higher rate of sea level rise during the 1980s, after a lower rate in the 1970s. North Shields had a lower rate of sea level rise in the 1960s and a higher rate in the 1970s.

Both sites had slower sea level rise in the last decade. North Shields data for 2018 and 2019 are not complete, but continue to show a slower rising trend. For BOTH locations, the latest decade rise is less than in some decades in the 20th century.

Slower sea level rise in the 1960s and 1970s is seen at many other sites around the world. The Arctic was unusually warm in the 1920s and 1930s, followed cooler weather until the 1990s.

If sea level rise was really accelerating as climate alarmists would have us believe, then why is London building London Gateway port at sea level ... and why did the Maldives islands build 17 airports, when they were supposed to be under water in year 2000 (look up pictures of the "sinking" Maldives online to see the huge amount of money invested there!) ... and why is China building artificial islands in the South China Sea ... and why did Barack Obama buy an $11 million mansion near sea level ?

And how about Diego Garcia, an atoll that's part of the U.K. overseas territory, perennially "sinking"? There's a large US air base there, used also by long-range B 52 bombers. There are no Diego Garcia climate scare stories ... probably because the U.S. pays the U.K rent to use the island -- no reason to scare us away!

The Romans built Pevensey castle on a peninsula, with water on three sides. It was first constructed as Anderida – one of the Roman ‘Forts of the Saxon Shore’. In 300AD, the sea lapped the walls of the original fort in a period, once known as the ‘Roman Warming’. As you say, William the Conqueror was able to harbor his invasion fleet adjacent to the fort over 700 years later in a period once known as the ‘Medieval Warming’.

Now, if you wanted to attack Pevensey Castle with a fleet of ships, you’d have to anchor your ships in the English Channel, and march at least one mile inland to reach the once coastal castle! That’s a modern man made sea level "catastrophe" for you! Seventeen hundred and twenty years of rising sea level would have brought the sea even closer to the castle walls than in 300AD ! That obviously did not happen.

When climate alarmists try to defend their false claims of accelerating sea level rise, they often bring up Bangladesh. This is just one huge delta for some of the largest rivers in Asia and, like all deltas, its levels go up and down erratically. Bangladesh is really on the Bay of Bengal for which the records show absolutely typical sea level changes of 1 to 3 mms per year.

The most accurately measured geophysical parameter for the Earth is variations in the Length of Day (delta LOD). Modern atomic clocks measure this planetary rotation rate to an astonishing degree of accuracy. Short term changes in LOD are caused by fluid movement over the surface of the Earth and in particular the movement of water in the oceans. LOD is a precise measurement, not a computer model spouting someone's opinion.

Melting ice at high latitudes travels as liquid water to low latitudes and in doing so this water mass moves away from the spin axis of the planet. Think of a spinning ice skater moving her arms away to slow down. The radius of the Earth at the equator is 6,378 km, so if we melt a mass of ice from the South Pole and move it to the Equator, then the water moves a distance of 6,378 km away from the spin axis of the planet.

If a catastrophic change in sea level was occurring we would see this (with a small lag) as an increased slowing in the rate of rotation of the Earth. No such effect is observed in the LOD. So the climate alarmist claim that sea level rise is accelerating is bogus. There is no cause for any alarm.

The pro-climate alarmist biased IPCC report gives a mean sea level rise since 1901 of 1.7 mm /year. They noted that the rate between 1993 and 2101 had increased to 3.2 mm/y but that this rate had occurred previously (1920 – 1950) and so was of limited significance. Some people claim that the increased rates between 1993 and 2010 were significant, but the rate of rise since 2010 is zero. Any trend over less than 30 years should not be considered as significant according to the WMO.

The National Tidal and Sea Level Facility (NTSLF) is the UK center of excellence for sea level monitoring, coastal flood forecasting, and the analysis of sea level extremes. It is the focus for sea level research in the U.K., and for its interpretation into advice for policy makers, planners and coastal engineers. it states a 1.4mm +/- 0.2mm per year average U.K. rise. Not explained are extreme tidal ranges in the early years of the 20th century, with standard deviations three or four times the SD in the later record. They means high tide levels at start of 20th century often exceeded high tide levels today. So the U.K. is actually at less at risk of high tide flooding now.

The definitive source for global tidal gauges is NOAA (U.S. Commerce Department) and their Tides and Currents department. They publish data for 366 long-term tidal gauge stations, which show a wide range of variance around the world, as land moves, along with sea rise from melting ice, affecting regions differently. Sea level changes vary from rapid rises to large falls.
https://tidesandcurrents.noaa.gov/sltrends/mslGlobalTrendsTable.html

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Sunday, October 18, 2020

U.K. (and global) sea level rise shows no acceleration from global warming