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Beach photo from 1905 does not disprove climate change

Or is comparing two snapshots simply ignoring the fact that season, tide, water temperature, etc. also have an influence on the water level?

Author: Walter Feichtinger

The claim

Two photos of Balmoral Beach in Sydney - one from 1905, one from 2019 - are intended to prove that sea levels are not rising

Our conclusion

Measurements in the immediate vicinity and on Sydney Harbor show that sea levels have risen continuously over the last hundred years

Climate change is the greatest global threat of the 21st century. Tens of millions of people are already fleeing the effects of this catastrophe. While heat, drought and a lack of water are causing problems for people on the African continent, at the other end of the world there is too much water. Rising sea levels threaten to wash away the ground beneath oceanic islanders' feet.

But maybe that's not true? Maybe global warming, the melting of the polar ice caps and the expansion of the oceans due to increased water temperatures is just an illusion? Comparing photos near Sydney proves the opposite? Spoiler: No, he doesn't!

The claim on social media

___STEADY_PAYWALL___

The beach and the sea level measuring stations

Balmoral is part of the affluent suburb of Mosman near Sydney, Australia. The place is known for its beach close to the city, which is officially divided into two sections: Balmoral and Edwards Beach. In between, a rock protrudes into the water called Rocky Point. In the two beach photos you can see a piece of Edwards Beach, Rocky Point and the mouth of Middle Harbor into Port Jackson.

MIMIKAMA
Edwards Beach (1), Rocky Point (2) and measuring station No. 2358 – Sydney Port Jackson (3)

A permanent service for mean sea level (PSMSL) measuring station has been operating on a jetty right in the mouth area since 1987. The records of monthly and annual mean sea level at this location can be found on the PSMSL website. The upward trend in the measured values ​​can already be clearly seen.

MIMIKAMA
Monthly (blue) and annual (red) averages at station 2358 – Sydney Port Jackson

Four other such measuring stations were and are operated in the harbor area of ​​Sydney and Botany Bay, the oldest at Ford Denison since 1886. The following diagram shows the monthly mean sea level at the measuring point, excluding the regular seasonal fluctuations that affect the temperature Salinity, winds, air pressure and coastal ocean currents. The long-term linear trend is also shown, including the 95% confidence interval.

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Monthly average values ​​and the trend (red) over 136 years of measurement history

On average, sea level in Sydney Harbor is rising by 0.75 millimeters per year. At Balmoral Beach, which is only about four kilometers away, the value will probably only differ slightly. If you take the two photos from 1905 and 2019 again, the result is an increase in sea level of around 86 mm. Just a moment…

Factors influencing the water level

The historical beach photo shows a summer bathing scene and the color photo was taken in mid-October. Does the month perhaps also make a difference? Yes, it does: by up to 94 millimeters. In the diagram above, the seasonal fluctuations have been calculated out. They look like this over the course of the year:

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Don't forget, in the southern hemisphere summer begins in December

In addition to these seasonal fluctuations, which can be attributed to temperature, salinity, winds, air pressure and ocean currents on the coast, there is another massive influencing factor: the tides. The largest difference between high and low water recorded in Sydney was 2.0 meters. Today (December 13, 2022) it is 1.0 meters.

And what does this knowledge mean for the comparison of the two beach photos? Depending on the tides and seasonal fluctuations, the water level at Balmoral Beach can vary greatly. If you knew the exact day and time of the recordings, you could calculate the respective water level. Without this important detail, the beach photos have no meaning whatsoever.

Similar claims and their refutation

MIMIKAMA
The Flat Earth society has members all around the globe

Yet another image comparison that is often shared shows that sea levels in Sydney Harbor have not risen. A fact check from USA Today makes it clear: That's not true!

The waterline in the harbor fluctuates daily due to the change of the tide and the photos do not contain any information about the tide level at the time the photos were taken. Tide gauges and other records show that sea levels in Sydney Harbor have risen steadily over the past 90 years, although more slowly than other coasts around the world.

Fact check: Sea levels at Sydney Harbor are rising, data shows
MIMIKAMA
Photos of Fort Denison in Sydney Harbor from 1878 and 2018

Not exactly a beach photo: Reuters looked at the images of Fort Denison and asked several experts what they thought about the photos and the claim. The short conclusion: “Wrong. It is not possible to accurately measure sea level rise by simply comparing two photos.”

Imagine the first picture was taken at high tide and the second at low tide. The apparent change could look like a falling sea level, when in reality the sea level is slowly rising! The complexity of sea level changes has necessitated the deployment of a network of continuously measuring tide gauges around the world, which is now complemented by satellites that constantly monitor sea levels.

Beata Csatho, professor and chair of geology at the University at Buffalo and a member of NASA's sea level change team, told Reuters

Beach photo: Palm Beach and the human factor

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And another beach photo near Sydney. This time Palm Beach, about 40 kilometers north of the city center. This is where several phenomena come together that affect the shape of the coastline, as Lead Stories writes:

Palm Beach experiences two high tides and two low tides daily, with water levels typically changing by about 5 feet (1.75 meters) every six hours, which can change the apparent width of the isthmus. Not only are the tides constantly changing the waterline on the coast - the beach itself is also variable and can be changed by storms, ocean currents, coastal drift and human actions, which can alter the lateral movement of sand and sediment that forms the beach.

Fact Check: Historic Photos Of Sydney's Palm Beach Do NOT Prove Climate Change Is 'Hoax'

The Australian Daily Telegraph has discovered two more interesting facts about Palm Beach (including historical beach photos): The peninsula was once an island and the connecting strip of land and sand only formed over the course of thousands of years through deposits. And the second fact directly concerns the photos of the false claim: intensive human use since the arrival of the first fleet left clear marks on the beach section. In just 100 years, the height of the isthmus halved from 10 to 12 meters (1876) to 5 to 6 meters (1977).

Fortunately, in the 1970s and early 1980s, the dynamics of the isthmus were explored and remedial work was undertaken to stabilize the sand. Bulldozers were used to reshape the isthmus, extensive plantings of various types of dune grasses, trees and shrubs were undertaken, and car access was restricted. Although the isthmus may never return to its pre-1788 extent, at least what remains of the geologically significant portion of the peninsula has been saved.

Daily Telegraph, 19.12.2014

Conclusion: Two beach photos without a date and time prove nothing. Many factors affect the coastline of a section of beach: tides, seasonal fluctuations, human use and more. The only thing that has any real significance is regular measurements. And unfortunately these show that sea levels are rising worldwide.

Sydney and Balmoral Beach are still doing relatively well, as the Coastal Risk Australia 2100 shows. Countries like Bangladesh are much more severely affected: a one meter rise in sea level there would flood almost 20 percent of the country and force more than 30 million people to flee their homes.


Sources: PSMSL , NOAA Tides & Currents , USA Today , Reuters , Lead Stories , Daily Telegraph , Coastal Risk Australia 2100 , Scientific American , Tidal Fish

More fact checks: People and CO₂ have nothing to do with climate change?
Nonsense!

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Notes:

1) This content reflects the current state of affairs at the time of publication
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The reproduction of individual images, screenshots, embeds or video sequences serves to discuss the topic. 2) Individual articles (not fact checks) were created using machine help and
were carefully checked by the Mimikama editorial team before publication. ( Reason )


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