Venice and Unenlightened Climate Fear-mongering

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Guest post by Jim Steele,

Venice is composed of a hundred linked islands and sits in the center of the shallow Venice Lagoon. Island elevations are low and easily flooded during storms. The Great Flood of 1966 was the worst on record. Since then, Venice has been working to avert the next inevitable flood. But because its flood control projects were fraught with corruption and other difficulties, the government failed to prevent the 2019 flood. So, now experiencing its 2nd greatest flood, the mayor covered his political derriere and immediately blamed climate change. But that’s a tactic typical for politicians these days. In California, ex-governor Jerry Brown vetoed a bipartisan bill to secure the electrical grid. Shortly thereafter power-line sparks ignited some of California’s biggest wildfires, so of course Brown blamed climate change to disguise his policy failures.

As seen in Figure 1 above, sea level rise in the Venice Lagoon is modulated by how much water from the Adriatic Sea enters the lagoon via 3 inlets and how quickly it flushes out again. To prevent further flooding, Venice began designing the MOSE project, which would construct inflatable barriers that could be deployed when weather conditions predicted threatening inflows from the Adriatic Sea. High inflows from the Adriatic Sea are driven by the strength of the Sirocco and Bora winds that cause local sea level to surge.

Increasing Venice’s vulnerability, the land has been sinking. Dwarfing the 1.4 millimeters per year of estimated sea level rise, from 1930 to 1970 Venice sank at the rate of 2.3 millimeters per year, largely due to ground water extraction. After addressing that problem, the rate of sinking slowed, but Venice continues to sink at a rate of 1 millimeter per year. Furthermore, due to alterations of the lagoon’s basin, the amplitude of tides have been changing, which accounts for 20% of the rise in extreme sea level events. That tidal effect was largely due to alteration of flows through the inlets due to dredging for ship traffic, and alterations from the MOSE project.

As has become typical for every catastrophe, media outlets shamelessly and mindlessly blame climate change for Venice’s flooding. Others, like Dr. Marshall Shepherd writing for Forbes, attempted to appear more objective by acknowledging many factors had contributed to the flooding. But Shepherd’s real intent was to ensure that people would still blame climate change, at least a part, and that skeptics were biased by only focusing on Venice’s sinking land. But there is much more to the skeptics’ arguments. Furthermore Dr. Shepherd failed to provide any support for his climate change claims. But that is to be expected as the evidence provides very little support for Venice’s mayor or Shepherd.

If climate change had really played a significant role, then we would expect the flooding to be worse in 2019 when compared to the more “natural flooding” in 1966. But a comparison of floodwaters inundating Doge’s Palace (see below) suggests the flooding was slightly worse in 1966. Official measurements likewise determined flood levels in Venice Lagoon peaked at 74 inches, shy of the 1966 record of 76 inches. The climate change argument is weakened further when it is understood that the 1966 flood happened during a low tide, in contrast to the 2019 flood that happened during an extreme high tide. Furthermore, there is no correlation with global warming as the November 1966 flood happened when Venice experienced its coldest temperatures since 1924. Recent Venice temperatures are slightly less than the 1950s (Figure 2).

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The Venice Lagoon is situated at the northernmost end of the Adriatic Sea. The Adriatic Sea is bordered by mountains on both its eastern and western boundaries. That geography creates a funnel effect. Each autumn the Sirocco Winds begin to intensify. These winds drive warm air from Africa northward, which in turn pushes Adriatic Sea water northward up the “funnel”. The end result is sea water piles up in front of the 3 inlets and begins flooding the shallow Venice Lagoon. Stronger winds drive greater flooding. And if the winds are strong enough, they temporarily prevent sea water from exiting the lagoons, causing sea level to rise even higher.

Naturally it would be natural to ask if climate change has caused an increasing trend in the Sirocco Winds. But there has been no trend.

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We should also analyze how much has sea level rise affected Venice? It could certainly be argued that rising sea levels since 1900 contributed about 100 millimeters (4 inches) to the 1966 Great Flood as there was a steady rise in sea level between 1900 and 1970. But between 1970 and 2000 the Venezia (Venice) tide gauge shows sea level peaked around 7150 millimeters and then plateaued (Figure 3). Unfortunately, that tide gauge then moved to a new location designated Venezia II. There sea level began at a lower elevation and rose from 2001 to 2010, again plateauing just under 7150 millimeters (Figure 4).

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Because various parts of Venice are sinking at different rates, it is difficult to know how much the new tide gauge location affected new estimates of sea level change. However, due to the uncertainty caused by Venice’s sinking land, researchers typically compare Venice sea level trends to neighboring Trieste in the far northeast corner of the Adriatic Sea. There the land appears to be more stable. Surprisingly, the Trieste sea level trend has been declining since 2000 (Figure 5). So, it would appear impossible to attribute sea level rise in the Adriatic Sea and climate change to the 2019 Venice flood.

However, there is another factor to consider. The winds in the northern Adriatic Sea cause sea levels to oscillate from east to west across the Adriatic’s northern basin. When sea levels fall around Trieste, they often surge around the Venice Lagoon. That sea level surge is associated with higher sea levels in the lagoon. Thus, at least in part, higher sea levels in the Venice Lagoon are driven by an ocean oscillation that creates higher sea level surges. And when that oscillation coincides with strong Sirocco Winds, a sinking Venice should expect more flooding.

In contrast, it’s unclear what effect is caused by global warming. Perhaps it’s negligible. Unfortunately for the public, that doesn’t stop media outlets from falsely hijacking the hardships in Venice to push a climate crisis. Alarmists continue to falsely suggest that every catastrophe has been partly driven by CO2 global warming. Sadly, as savvy propagandists know, if you tell a big enough lie often enough, people will start believing the lie.

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Jim Steele is Director emeritus of San Francisco State’s Sierra Nevada Field Campus and authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism

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77 thoughts on “Venice and Unenlightened Climate Fear-mongering

    • Jim Steele’s articles are always a great source of facts and interesting to read. I’d been wondering what was behind this latest event since it was obviously much longer than any ‘king tide’ kind of effect. Many thanks for a cogent fact filled article. I will go to bed less dumb tonight, thanks to Jim.

  1. Once again making the point that “Climate Change” is both the excuse for past Progressive policy failure and the excuse for more Progressive policy.

    • One cannot reasonably expect very ancient cities, anywhere, to remain unchanged for centuries in the face of the ravages of time. Particularly when built on the water’s edge. Subsidence, erosion, tidal changes, everything Jim cites and then some. This is only common sense.

      A point I never see mentioned: We HAD to build large settlements on rivers and seas in ancient times because most goods could only be moved in bulk by ship. Today, there is ZERO reason to keep building high-rise housing, hotels, office buildings, etc. down to the water’s edge. Charging luxury prices for a premium “view” is a stupid way to invest money when it must be backed up by taxpayer flood insurance. Places like Miami Beach, it’s not a matter of “if” a hurricane will “devastate” the place, but WHEN.
      Only water-dependent businesses (marinas, shipping terminals, commerical fishing, boatbuilding) need to be built in water’s edge areas today. Estuary reclaimation is also a positive alternative to willful ignorance of weather’s inevitabilities.

      • There IS a massive reason for building on waterfront areas – these are always the most valuable lands, and the the free market demands that. What – you want the repeal the free market? Very unconservative of you.

        Besides, because these lands are by far the most valuable lands in the USA, the owners pay by far the highest volumeof property taxes, and capital gains taxes on them as they appreciate and are sold, far more than making up for any subsidies in the National Flood Insurance Program (NFIP) which, by the way, is compulsory to all lot owners who need mortgages.

        That isn’t going to change. Indeed, throughout human history waterfront lands have always been the most valuable, whether it was for purposes of views and aesthetics, or access to transportation. And even today, waterborne transport is still by far the cheapest means of transporting goods and supplies. Which is why ships and barges still transport the biggest bulk of goods.

        • Well, the lender is going to require insurance from somewhere. While the law may require an NFIP policy, laws can be changed. The problem becomes, the government is always an unfair competitor and therefore have driven away all competitors even if the law allows a borrower to obtain such a policy anywhere he pleases, those alternatives no longer exist, if they ever did. If an owner or developer had to obtain insurance on their waterfront property at a rate that would actually support insurance plans, the affect on development would depress prices. A plan I wholeheartedly support, while also recognizing the transition to such a model would be hugely disruptive.

          Consequently, I also disagree that “… these are always the most valuable lands…”. Wasn’t there a time, even in the memory of many reading here, that the roughest part of town was On The Waterfront? Even beach-front property had limited appeal. (I personally know the guy whose father’s business partner leveraged the west end of Galveston Island, expecting to develop it, shortly before Hurricane Carla. They went broke since no one would buy those lots, cuz no one could get insurance on anything they did build.) It wasn’t until the creation of government backed well-below-market-value insurance that these luxury developments could happen. Venice, and similar sites, were developed only by the ultra-rich who could afford the loss and maybe rebuild if a disaster happened. Assuming they survived.

        • Only federal backed mortgage loans are required by law to have the flood insurance although I do not know of any other mortgage lender that will not require it as a means to protect their interest in the collateral property. The determination is made by using base flood elevation maps compared to the elevation of the lowest living area of a home. Current construction of single family homes allows the build up of the land so that the lowest living area is above the base flood elevation even if the area is within a special flood hazard zone. Each property is evaluated on an individual case by case basis. Current codes along the coastal waters also require flow through non living areas under the residences.

      • As has been brought out here many times there are limits to how much NFIP covers. It is capped at $250K per residence, and $100K for contents. Above that the owner must buy private insurance. While the rates are kept artificially low due to politics, failure to educate yourself about those limits is no excuse for alarmist rhetoric.

  2. I was in Venezia 1980, 2″x6″ planks were perfectly placed throughout San Marco Square to allow for foot traffic, Venetians literally took all of this in stride going about their daily business. I recall while walking around Venezia many times (I lived in Vicenza), I would walk over to the steps that led to boat docks or tie up points for boating and count how many steps were under water and wonder who had at one time walked those steps that were submerged year-round.

    Dan

    • I was in the U.S. Army stationed at Vicenza, IT from 1976-1978 which is about 42 miles from Venice. It was less than an hour’s train ride one way and went to Venice often. The city floods most every year in varying amounts. As was mentioned, there are or were wooden platforms about St. Marks Square that are stored just outside of the plaza itself to be used when the square flooded. Much of the tourist attractions like the Campanile, The Duke’s Palace, the Basilica, etc. are all elevated from the square itself. That was over 40 years ago.

      • The platforms these days are metal tubing covered by wood. As you say, they are stored around the square.

  3. Reading about these factors and the 1966 event, one should expect something more extreme in the future even if we all stop breathing CO2.

  4. This level of flooding was one in 200 hundred years event. Spokesman for the St Mark’s basilica said that according to the records that are kept there, this is only the 6th time that the basilica’s crypt was flooded since it was consecrated in 832 AD.

  5. As a sometime Mediterranean sailor I was surprised to see that the maximum tidal range at Venice is 3.9 feet. Mostly quite a bit less but high for the ‘tideless’ Med.

  6. The pigeons! Think of the poor pigeons!!! They’ll starve if there’s no place to scatter the bird food that people throw out on the tiles of the public squares!!!

    This inundation, as the article says, has been going on repeatedly for a very long time. Nothing to see here, folks, move along, but remember, climate change can mean water retreats, too, as well as heavy snows in that part of the world.

  7. Further to. When I was a schoolboy and my daddy was confronting Tito in Venezia Giulia with his armoured brigade in 1947 I recall flooding in St Mark’s Square.

  8. Says it all.

    1969- “Italian and foreign scientists are racing against time to save the beautiful city of Venice from sinking into the waters it once ruled. It is estimated that at the rate Venice is sinking, two-thirds of the city praised by poets over the centuries will disappear under water by 1990”

  9. We were in Venice for last year’s aqua alta, which was only a few inches less tha this year’s. The worst of it was the afternoon we spent in the Academia Art Gallery, where water came into several ground floor exhibition rooms. It was quite an experience.

    I have devoted some study to the matter. The MOSE project is hopeless. Raising the ground level of the buildings is theoretically possible, but economically impossible. The best alternative would to be sound the main islands with a sea wall. It is not more difficult nor more dramatic that what the Dutch have done for years. They would have to find an alternative place for the Cruise Ships to dock, but the locals would cheer about that.

    The real problem here is Italian Politics which is hopelessly muddled. The best solution would be to break up Italy, and allow Venizia to be an independent republic once more after 230 years.

    • “alternative would to be sound the main islands with a sea wall.”

      should have been:

      “alternative would to be surround the main islands with a sea wall.”

      Sorry.

    • Unfortunately money speaks, and although the more far sighted Venetians complain about the cruise ships many others like the revenue they bring.

      It is simply absurd the way these cruise ship monsters are allowed to come right into the city, disgorge passengers on day trips, who then clear off back to the ship for their meals. They need to be accommodated well away from the city otherwise, as Walter points out, the sensible solution-a proper sea wall would not be possible.

      Venice is sinking noticeably and the waves from numerous ships big and small don’t help, combined with gently rising waters (perhaps) Mind you, even if sea level is flat, once a 2mm a year sinking of parts of the city are factored in it is clear that in 20 years time, with or without a major tidal event, more and more damage will be caused as sea water seeps into stonework.

      tonyb

    • I should add that Venice was an independent Republic for about 1000 years until Napoleon overran it in 1797. It was republic longer than Rome was or the United States has been.

      Good books on Venice:

      City of Fortune: How Venice Ruled the Seas (2013) by Roger Crowley
      https://www.amazon.com/City-Fortune-Venice-Ruled-Seas/dp/0812980220/

      Venice: A New History (2013) by Thomas F. Madden
      https://www.amazon.com/Venice-History-Thomas-F-Madden/dp/0147509807/

  10. Great write up. I always look to WUWT for a sane response to what’s written in the mainstream media..Take this piece, published yesterday by AP.. https://apnews.com/343886375fcb49e58ee188ddab0fbb0e

    As I was reading it, I kept waiting for the climate change reference. It was tucked down in the 8th paragraph, siting sinking land along with rising sea levels attributed to climate change..

  11. Anyone who lives in a inlet off a large body of water or a body of water like a river estuary that constricts as it goes inland knows what wind driven tides can do. If you have a persistent strong wind, a long fetch, a bottom that is getting shallower and/or the width between the shores is decreasing.. the water rises.. sometimes remarkably.

    Storm surges in a hurricane are a prime example. Also winds blowing across the North Carolina sounds can empty one side and flood the other. One of the best examples I’ve seen was when hurricane Isabel blew water directly up the Chesapeake Bay which narrows north of the Potomac River mouth. Annapolis MD had record floods. You could literally swim from one bar to another down on the waterfront in 8′ of water. All are a matter of local geography and wind direction, duration and strength. Nothing else.

  12. In retrospect, building a city of stone on soft, saturated sediments in an area prone to seismic activity was not a good idea. It gets back to the old real estate mantra: location, location, location.

    • When the residents of the are fled Attila the Hun, they thought it was great location. They held off foreign enemies, safe in their lagoon, until Napoleon showed up with modern artillery. Sometimes a source of strength is also a vulnerability. Their problem now is Italian politics, not the tides nor Global Warming.

      See my comment above.

  13. Excellent article Jim

    Paul provides an interesting link above, that gives details as to how the construction of Venice in the 5th Century affects it to this day, as it was built on great piles of wood which accrued silt

    This link gives a broader view of the history of this fascinating city

    https://www.thoughtco.com/history-of-venice-1221659

    Those citizens fleeing the Roman empire as it collapsed in the 5th century were looking for a place that was awkward for invaders to follow and Venice with its extraordinary topography was a good choice.

    It is a sensational place and I remember as a school child donating money in the 1960;s ‘Venice in Peril’ fund following the floods of 1966. Unfortunately much of the money seems to have been used incorrectly and the intended final fix Jim describes-based on the highly effective London Thames barrier- has been mired in corruption and poor design.

    I would urge our American friends to visit, but not by the hated cruise ships which are contributing to the problem. Come by train, then walk or take the water buses. Alternatively if you fly in to Marco Polo airport there is a water bus service from the airport jetty right into the centre

    Don’t come in summer when it is absurdly overcrowded and often hot and smelly. It is highly atmospheric in the surprisingly cold winter months with the fabulous masked carnival -usually in February- being a good focal point. People seem to come mainly for the carnival events meaning that the crowds for the major attractions were non existent.

    tonyb

    • Eric Newby gives a look at the history of “modifications” to the lagoon in the chapter on “Venice” in “On the Shores of the Mediterranean”

  14. As with many rivers in the US and related flooding, I wonder how much things are worsened by the silting in of channels and lagoons. A river that once was 5 meters deep floods much worse when it is only 1 meter deep. The Venice lagoons would be no different.

    • Recent floods in the UK have been blamed on climate change. Yet, it is actually lack of river system maintenance, silting etc, that is the primary reason as noted by a local farmer.

  15. Oscar Levant, the concert pianist, composer and movie actor of the 1940s and 1950s, visited Venice for the first time.
    He sent a telegram to a friend:
    “Streets full of water, please advise.”

  16. Glad you brought this up — Venice has been sinking into the sea for centuries (FAR FASTER than any reasonable estimate of current sea-rise), and the Venicians continue adapting — in fact, it’s a major attraction as a result.

    So scary, not.

  17. Great write-up, Jim Steele, and up to your usual excellent standards. However, you are badly mistaken about the location of Venice, it is in the Venetian Casino in Las Vegas. Been there, done that, rode the gondolas, Italian operas singing everywhere, tiramisu for dessert, etc. Otherwise, good report.

  18. Furthermore, the body that governed the waters of the lagoon and the rivers on the mainland – Magistrato delle Acque – was broken up after the MOSE corruption scandal and its competencies divided between a number of other institutions, and this probably does not help with good management of the situation either.

  19. Apparently Vanvitelli’s art from the 1700’s is good enough to use a tide gauge. Santa Maria Della Salute is fabulous, count the number of exposed steps. Of course, this doesn’t show flooding.

  20. A great article–it seems like Venice is prone to mini-“storm surges” whenever the prevailing wind is out of the southeast. The fact that the sea level is falling at nearby Trieste rules out any effect from global warming or melting of the ice caps.

    There was a similar storm surge effect in Raritan Bay (off northeastern New Jersey) and New York Harbor, causing major flooding during Hurricane Sandy. Lots of commentators at the time (2012) blamed “global warming”, but the real problem was that the center of Sandy made landfall near Atlantic City, with strong winds out of the southeast (with a long fetch of ocean water) into Raritan Bay and New York Harbor. Most other strong storms in that area have winds out of the north or northeast, which tend to push water out of New York Harbor. The center of Sandy was pushed westward into southern New Jersey by an unusually cold air mass over the North Atlantic, and Sandy brought heavy snow to West Virginia in late October. But the AGW alarmists blame global warming for everything, including cold storms!

  21. To add to Steve Z’s post, a similar hurricane on a similar track occurred in 1903, however, with much less improvement along the NJ coast, there was a dearth of reported damage. That 1903 event was apparently a smaller storm geographically, though, whereas Sandy was larger, and consequently surge damage occurred much further north in the NYC area and western Long Island. Of course, the 1962 nor’easter of record was just as devastating as Sandy, but a tad further south so it affected NJ and points south along the Delmarva peninsula and DE Bay. Of course, it was a much longer duration event, 5 high tide cycles, so the devastation was done through a different mechanism. And, by the way, Sandy really was a hurricane at landfall, as temperatures rose at at least one observation site on the coast (so it was still slightly warm core). But, of course, as the call had been made days prior to landfall that Sandy would become extratropical before landfall, observations be damned. Thanks, NOAA. /sarc

  22. Venice was built on wood pilings driven into mud banks for defensive purposes. First from the Huns as the Roman Empire declined and could not defend it’s self and later from other invaders or competing city states during the dark and middle ages. The security that the very limited avenues of approach provided is the primary reason for the accumulation of the architectural and other treasures there which tourists flock to see today. People with means flocked there because of the stability the security provided.

    One problem I have read about elsewhere I did not see Jim mention, I assume because it has nothing to do with “climate change”, is erosion of the wood pilings. Motorized craft and ships traveling in the shallow waters kick up silt and sand which is abrading the pilings along major waterways.

    • rah,

      For the sake of relative brevity, there are many things I did not write about. I can only present a relatively short essay that people can finish and hope it serves as a springboard for further discussion. The WUWT readers are highly educated, and like you do a good job of filling in the “blanks”

      • rah & Jim,
        Good comments from both of you. And Thanks for the work on this, Jim.

        I’ll toss out the question about sedimentation from the hinterlands.
        Or said another way, has the volume of the lagoon decreased as
        physical weathering in the uplands proceeded.

  23. Visited Venice several years ago. How they deal with sewage disposal is interesting. With the mold scares of recent years one would wonder why this doesn’t seem to be a problem with Venetians.

  24. I was there a few years ago and a king tide caused some minor flooding, but enough to see how precarious the situation is. It’ll be very tricky to fix the problem (or environment around it).

  25. I’ve been there several times in the last forty years. My spouse, who’s been there many more times, could navigate the place blindfolded.

    Raised walkways to handle minor flooding have always been a common sight. When you see them the first time you wonder what they are for! They look like a bunch of cheap folding tables strung out for a hundred feet or more.

    In 1966 a bad flood affected Venice as well as Florence on the Arno river, resulting in some major loss and damage to precious art objects, including Cimabue’s crucifixion.

    So…Major floods go way back, and can’t be blamed on AGW.

    Apparently, so-called journalists have never heard of subsidence.

  26. http://themeditelegraph.com/en/shipping/cruise-and-ferries/2019/05/25/venice-port-dredging-should-start-immediately-interview-hpdYTamDABosaCgWxcRFiO/index.html

    This dredging has been going on for years. They still want more. When channels are larger, there is less resistance to flow when the sea level changes. Water will rise faster in the city center, brought in by the dredged channels, resulting in less elevation difference between the sea, and the city center at maximum. Wind driven water levels are also impacted. Do you want tourist dollars, or lower levels? The same authorities screaming climate change causes voted for dredging, and are pushing for more.

  27. The data set of the tide gauge in Venice stopped 2000. There is also the issue, that the land near Venice sinks down. I checked the gauge in Trieste, only 115 km away from Venice and also measuring the tide of the Adria. The impact of the global SLR should be identicaly. The data of Trieste: https://www.psmsl.org/data/obtaining/stations/154.php .
    Since 1966 ( the last big Venice flood) the sea level rise was 5.7 cm. The present flood was 1.20 above normal, this gives about 5% as the part of the SLR. Not a very strong argument for the claim: SLR causes the going down of Venice.

  28. Hello, congratulations on the excellent work. I am preparing a huge article with dozens of studies on sea level worldwide, as a non-existent threat. Specifically Venice suffers problems due to other factors, because the sea level remains stable, there is no acceleration or anomaly.

    -MÖRNER, N. –A. Chapter 12 – Sea Level Changes as Observed in Nature. Evidence-Based Climate Science (Second Edition). Data Opposing CO2 Emissions as the Primary Source of Global Warming. Pages 215-229. 2016.
    https://www.sciencedirect.com/science/article/pii/B9780128045886000124

    Abstract
    “Observational facts recorded and controllable in the field tell a quite different story of actual sea-level rise than the ones based on model simulations, especially all those who try to endorse a preconceived scenario of disastrous flooding to come. ”

    “Poster sites” like Tuvalu, Vanuatu, and Kiribati in the Pacific have tide gauge stations indicating stable sea-level conditions over the last 20–30 years. The Maldives, Goa, Bangladesh, and several additional sites in the Indian Ocean provide firm field evidence of stable sea-level conditions over the last 40–50 years.”

    “Northeast Europe provides excellent opportunities to test regional eustasy, now firmly being set at +1.0 ± 0.1 mm/year. Other test areas like VENICE, Guyana–Surinam, Qatar, and Perth provide a eustatic factor of ±0.0 mm/year. We now have a congruent picture of actual global sea-level changes, ie, between ±0.0 to +1.0 mm/year. This implies little or no threat for future sea-level problems.”

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