A critical global shipping node – Egypt’s Suez Canal – was reopened on Monday, March 29, six days after being shut down when the 400-meter-long container ship Ever Given became lodged in the canal. A statement by the Suez Canal Authority initially blamed the incident on high winds and a sand storm that reduced visibility, but later said that strong winds were “not the only cause,” and that an investigation was ongoing.

There is no clear indication at this point that climate change played a role in the sandstorm that led to the ship’s blocking the canal, but the incident raises intriguing questions that likely will prompt research into any correlation.

The multi-day shutdown of one of the world’s busiest shipping chokepoints underscores the vulnerability of the global food system and economy to disruptions. That vulnerability is playing on the stage of increasingly extreme weather, rising seas, and an increasingly just-in-time world of shipping.

Figure 1 - satellite image on ship's grounding
Figure 1. MODIS satellite image from March 23, 2021, the day of the grounding of the container ship Ever Given in the Suez Canal. A cold front over Egypt was causing a widespread dust storm that affected the Red Sea, Suez Canal, and waters of the Mediterranean Sea. (Image credit: NASA Worldview)

Meteorology of the event

The high winds and sand storm that contributed to the grounding incident were caused by a cold front trailing to the south of a low-pressure system centered near southern Turkey.

As the cold front swept eastwards across Egypt on March 23, powerful winds of 25-30 knots (29-35 mph) blew along the axis of the Red Sea from the south-southeast, into the southern end of the Suez Canal, as seen in the 6 UTC analysis from the GFS model (Figure 2). The Ever Given became stuck at 05:40 UTC that day. According to the GFS analysis, a sharp wind shift, with winds blowing out of the southwest to west, was present near the spot where the Ever Given blocked the canal, about five miles north of its connection with the Red Sea.

The New York Times reported that winds in excess of 70 mph blew in the region where the Ever Given became stuck; the owner of the ship, BSM, said that “initial investigations suggest the vessel grounded due to strong wind.” The strong winds were accompanied by large amounts of sand and dust, reducing visibility and making navigation more challenging.

Winds this strong are uncommon in the region, but strong winds have delayed shipping traffic or closed the Suez Canal on at least two occasions – December 11, 2010, and February 11, 2015.

Figure 2 - GFS model analysis
Figure 2. The GFS model analysis from 6 UTC March 23, 2021, at the time of the grounding of the Ever Given. Sustained south-southeasterly winds of 25-30 knots (29-35 mph, yellow-green and yellow colors) were blowing across the Red Sea into the entrance of the Suez Canal. The black wind barbs show a sharp wind shift was present near the southern portion of the canal, where the Ever Given became stranded. (Image credit: Tropical Tidbits)

A video Tweeted by Vakrio Technologies showed the course and heading of the Ever Given as it entered the canal, demonstrating that the canal is initially angled from southwest to northeast. Ever Given passed very close to the northwest bank of the canal at the start of its traverse, presumably pushed by the strong south-southeasterly winds blowing into the canal entrance from the Red Sea. For unknown reasons, the vessel was moving at 15 mph, well in excess of the 10 mph speed limit in the canal. As explained in an excellent analysis in the Financial Times (free registration required) by Brendan Greely, when a ship gets too close to a bank, shallow-water hydrodynamic forces can act to spin the boat – a well-known phenomenon known as the bank effect, where the water speeds up between the boat and the bank, the pressure drops, and the stern is pulled into the bank while the bow is pushed away from shore. Possibly because of the bank effect, the Ever Given then slewed close to the opposite (east) bank of the canal. At that point, the canal is oriented north-south, and the vessel angled its heading to the left, perhaps again due to the bank effect, or possibly in response to a crosswind that had developed due to a wind shift to a more westerly direction. The ship again came close to the west (left) bank, potentially because of a swirling wind that briefly blew from the south, reducing the cross-wind component that was pushing the boat to the right. The Ever Given finally ran aground with its stern on the west bank of the canal and its bow on the east bank (Figure 3), suggesting that the bank effect may have acted to spin the ship and lodge it in the canal when it came too close to the west bank.

Figure 3 - satellite map of Ever Given stuck in the Suez Canal
Figure 3. Sentinel-2 satellite image of the Ever Given stuck in the Suez Canal on March 24, 2021. The stern of the ship was lodged against the west bank of the canal. (Photo credit: Pierre Markuse)

Near-record March heat preceded the March 23 sandstorm

An extraordinary March heat wave preceded the cold front and sandstorm that contributed to the canal-blocking incident; the day previously, Kharga, Egypt, recorded a scorching temperature of 44 degrees Celsius (111.2°F), just 0.2 degrees Celsius below the highest March temperature ever recorded in the nation, according to weather records expert Maximiliano Herrera. The day of the sandstorm (March 23), Luxor, Egypt, hit 43.6 degrees Celsius – just 0.6 degrees Celsius below the March national record. Herrera documented that on the day after the sandstorm, Mitribah, Kuwait hit 44.6 degrees Celsius (112.3°F) – the hottest temperature ever recorded in the Arabian Peninsula in March.

Extreme heat dries the soil, allowing winds to more readily mobilize sand grains and create a dust storm. For example, a study of a high-impact sandstorm over the Middle East during August-September 2015 found that unusually hot and dry conditions preceding the event were responsible for its near-record intensity.

“The simulations showed that what was very unique about this storm is that, first, it was preceded by a very hot period, and so the land that was not covered with vegetation would be drier and it would be easier to entrain sand grains from it,” said study co-author Eli Bou-Zeid, in an interview with the Climate News Network.

Similarly, when the strong cold front swept through Egypt on March 23, 2021, the winds behind the front were able to loft an unusual amount of dust and sand into the air because of the earlier hot conditions. That created difficult circumstances for navigation on the Suez Canal. Climate change is increasing the incidence of such extreme heat events, and may have played a role in the blockage of the Suez Canal if reduced visibility is determined to have played a role in the ship’s grounding.

Figure 4 - GFS model analysis
Figure 4. The GFS model analysis from 6 UTC March 23, 2021, at the time of the grounding of the Ever Given, showing the departure of temperature from average. Temperatures were as much as 20 degrees Celsius (36°F) above average to the east of a cold front moving across Egypt. (Image credit: Tropical Tidbits)

Wind a more likely culprit than poor visibility

Wind appears to be the main culprit for the grounding of the ship, however, with the sandstorm’s strong and variable winds making it more difficult to navigate the passage. For now at least, it’s speculative whether climate change may have increased the odds of the strong wind event on March 23.

However, the large-scale weather pattern responsible for the sandstorm was quite extreme, and climate change could have contributed to make this event more extreme. Observations of the upper-level air patterns at 500 millibars (about 18,000 feet) on that date showed a very amplified and wavy jet stream pattern, with a strong ridge of high pressure over the Middle East and a strong trough of low pressure just to its west over the central Mediterranean Sea (Figure 5). Both features were about two standard deviations from the mean.

There has been a sharp increase in similar “global weirding” extreme jet stream patterns in summer, as a result of a phenomenon known as quasi-resonant amplification or “QRA” – described in detail in an October 2018 realclimate.org post by Michael Mann and reported in this writer’s 2018 post at Weather Underground. Modeling studies have shown that climate change may be responsible for the observed increase in summer QRA events, potentially because of how the Arctic is warming up more than twice as fast as the planet overall. A March 2021 study, “Large scale connection to deadly Indian heat waves” found that QRA events can also occur in spring, and may be connected to deadly April and May heat waves that affected India in 2010-2015.

But Dr. Stefan Rahmstorf, a co-author of the 2018 QRA study, wrote in an email that there was no evidence of QRA conditions during the week leading up to the Suez Canal sandstorm on March 23. Dr. Mann, lead author of the 2018 QRA study, added, “Our work certainly supports the increased incidence of persistent weather extremes of this sort (in fact, there’s a new study just out that further confirms that these events are indeed increasing in Europe during the warm season), so the connection is plausible but not confirmed.” Thus, it is possible that climate change may have increased the odds of the unusually amplified jet stream pattern responsible for the March 23 wind event in Egypt, but this possibility is speculative, and only more research may lead to further understanding of a possible connection with a changing climate.

Figure 5 GFS model
Figure 5. Northern Hemisphere 500-millibar heights (in decameters, or tens of meters) from the GFS model analysis from 6 UTC March 23, 2021, at the time of the grounding of the Ever Given. Colors show how much the predicted 500-mb height deviates from the average for this time of year, in standard deviations. Ridges of high pressures are shown in orange, and troughs of low pressure are blue; Egypt was located at the boundary between a strong trough of low pressure and strong ridge of high pressure. (Image credit: Tropical Tidbits)

Climate change increasingly likely to threaten global trade chokepoints

While the connections to climate change of the grounding of the Ever Given and closure of the Suez Canal are speculative, the event serves as a warning that climate change can be expected to cause an increase in extreme events that will impact critical global trade chokepoints. As explained in a 2017 report from Chatham House, much of the food required to feed 2.8 billion people passes through 14 critical shipping chokepoints (Figure 6): maritime corridors such as straits and canals, coastal infrastructure in major crop-exporting regions, and inland transport infrastructure in major crop-exporting regions. These chokepoints are at risk of closure due to three factors:

1) Extreme weather events or sea level rise;
2) Security and conflict hazards from war, political instability, piracy, organized crime and/or terrorism; and
3) Decisions by authorities to close a chokepoint or restrict the passage of food (for example, by imposing export controls).

Thirteen of the 14 critical chokepoints have had a closure or interruption in transit at least once between 2002-2017, with the Strait of Gibraltar the only exception. Many of these events had potential climate change connections: for example, the 2011 and 2012 heat waves in the U.S. that led to multiple derailments of trains where railroad tracks warped in excessive heat.

Figure 6 Key global chokepoints
Figure 6. Key global chokepoints for shipping. (Image credit: Chatham House, adapted from Rodrigue, J.-P., Comtois, C. and Slack, B., 2017, “The Geography of Transport Systems,” New York: Routledge

The report explained, “Climate change is increasing the threat of disruption by acting as a hazard multiplier across all three categories of chokepoint risk. It will increase the frequency and severity of extreme weather, leading to more regular closures of chokepoints and greater wear and tear on infrastructure. Rising sea levels will threaten the integrity of port operations and coastal storage infrastructure, and will increase their vulnerability to storm surges. Climate change is expected to aggravate drivers of conflict and instability. It will also lead to more frequent harvest failures, increasing the risk of governments imposing ad hoc export controls.”

The forced closure of the Suez Canal due to a possibly climate change-related event should act as a warning: Climate change will cause disruptions to critical global trade chokepoints more frequently in the coming years, and we need to take strong actions to reduce emissions of greenhouse gases and reduce vulnerabilities to chokepoint disruptions.

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Jeff Masters, Ph.D., worked as a hurricane scientist with the NOAA Hurricane Hunters from 1986-1990. After a near-fatal flight into category 5 Hurricane Hugo, he left the Hurricane Hunters to pursue a...

37 replies on “Suez Canal shutdown shows the vulnerability of the global economy to extreme events”

    1. lots of good snapshots from last year’s wildfires! wonder If the smoke will make it up NORTH again!

  1. we just sold our condo on the beach in miami as there is a run on real estate here at the moment! – and while it wasn’t because of climate change – that was always in back of the mind. planning to move to western US away from coasts (there are disasters everywhere – but not where your city could be underwater in a couple decades) – but its almost a relief to think that we won’t have to worry about living on the water 10 years from now as the reality of what is going on really starts to sink in. it is scary stuff – not fun to think about – but easier now, now that we are not along the coast w/ our main asset so exposed to disaster. you wonder if big govt. spending in the future should be on infrastructure in cities like Denver, boise etc. instead of south florida, where people will need to flee to higher ground.

  2. A while back you wrote an article about the Mississippi and its flood control system. IM sure also vulnerable

  3. In case you missed this story:

    NWSChat is an Instant Messaging program utilized by NWS operational personnel to share critical warning decision expertise and other types of significant weather information essential to the NWS’s mission of saving lives and property.

    <b>This information is exchanged in real-time with the media and emergency response community, who in turn play a key role in communicating the NWS’s hazardous weather messages to the public.</b>
    (emphasis added)


    From WaPo:
    On March 15, the Weather Service office in Birmingham, Ala., sent an email to media partners about its decision to switch to Slack, an instant messaging program, ahead of the tornado outbreak March 17 that unleashed nearly 50 twisters.

    <i>“In the interest of public safety and due to factors beyond our control, NWS [Birmingham] will be SWITCHING to Slack Chat as our PRIMARY means of realtime communication until such a time that NWS Chat is proven stable, reliable and has a reliable backup service in place,” read the email sent by warning coordination meteorologist John De Block.</i>

    The Weather Service in Birmingham declined to comment on its switch to Slack, but received instruction from higher-ups not to do it again.

    “Offices were provided guidance not to procure their own alternative platforms. This function is the responsibility of NWS headquarters, not individual offices,” wrote Weather Service director of public affairs Susan Buchanan in an email.

    NWS Chat also went down for a time Saturday evening as tornadoes tore through Arkansas, Texas, Mississippi and Tennessee and deadly flash flooding engulfed Nashville.

    “And down goes my beloved NWS Chat,” tweeted Daryl Herzmann, a systems analyst at Iowa State University who first helped develop and implement NWS Chat years ago. “I wish I could find some mechanism to help them fix it. [Tens] of unanswered emails so far.”


  4. great article, eg climate change as a risk multiplier; not the cause of accidents but the increase in stressors that make them more likely!


  5. Our supply chains are tight as violin strings. Any disruption at all is bound to reverberate. But resilience is costly, eh.

  6. This Article, breaking down the weather conditions at the time of the grounding is outstanding and Thank You. In terms of the dust/sandstorm issue (outside of the main wind issue) as you have also noted, we have seen the prevalent heat anomalies recently from the Middle East, over to the Himalaya’s, and on to Central Asia. In fact, as of this current period, that general anomaly is still in place: that hot/dry weather (in terms of dried out top-soils) can help kick up a lot of dust in a windstorm

  7. Thank you for this. Two very separate thoughts…..

    I have read that “human error” is being considered as a cause in the Ever Given getting stuck. Where is the line between the human error of visibility and the loss of visibility due to blowing sand? It would be very easy to write off climate change as a cause if the same thing can be labeled human error.

    Transportation Geography is global. So is climate. It would make such a good starting point for multinational cooperation, and highlights the importance of the African continent. Please write more about this stuff.

    1. It is way too easy to call it climate change. Climate relates to very long patterns; weather relates to short term conditions. High winds and sand storms are common in the area – we don’t need to have record high temperature to have a situation like this.

      My take is that the enormous weight of a freight carrier like Ever Given is a serious factor; the Suez canal is not built (depth wise or width) to accommodate such vessels.
      And they should, for the sake of good order, have tested the captain’s blood for alcohol (too late now). Alcohol has been a factor in many ship crashes in the past decade.

  8. As freighters keep getting larger with containers stacked higher they will be more likely to be affected by winds.

  9. On the other hand, climate change raises sea level, increasing the cross-sectional area of Suez Canal, making it easier for ships to fit there (at any orientation).

    Personally I don’t see, how sandstorm wind speeds could be expected to increase due to climate change, but there is another phenomenon to consider. Just in late 2019, the first recorded tropical cyclone (medicane) hit northern Egypt. It was just a low-end tropical storm, but in future, they could be stronger.

    When it comes to chokepoints, most of those will not be as critical as before, once Arctic Ocean melts. Then Bering Strait becomes a chokepoint. In the early stages of Arctic melting, Northwest and Northeast passages are two long chokepoints, but they will be erased soon after, once central Arctic becomes navigable too.

    1. I suppose you could consider sharper temp gradients (stronger/more winds), less rainfall in already arid areas. Then you might look at the economics of running the Arctic route for many locations in the world.

      1. There are no reasons to expect sharper temp gradients – Arctic is warming faster than equator. Rainfall doesn’t affect the situation the way you’d like to imagine. And yes, I have looked at the economics, even though you’d like to believe otherwise… but you already knew that. Sorry for a heretic like me spoiling your narrative.

      2. I don’t mind your ability and freedom to question my imagination, narrative, or expect you to apologize for spoiling my day.

        You and I are firmly entrenched in the platform we have chosen to stand on. And there is very little incentive or value in either of us in trying to change that. So I will leave personal side of this behind and leave you to your narrative.

        I get your view. Tacit acceptance on your part that the planet is warming. 

        There is an overwhelming landslide of peer-reviewed papers and studies of the week that point to the use of fossil fuels as the primary cause. To be honest, I have not made much of a look in the opposite direction. A conspiracy/a lack of evidence? Won’t argue that point or request a list of benefits of a warming world-although I would certainly give it a read.

        Some credible evidence must exist that the harmful forecasts/observations of rising sea level due to the melting of land ice and the loss of oceanic ice/albedo are a good thing.. Evidence that these perceived harmful effects will provide many positive things. Easier transits for bigger ships in the Suez and a year-round passage through the arctic are two benefits that you mentioned. An economic boon for sure.

        So where does that leave you and I? You believe the planet is warming and the positives outweigh the negatives on a GLOBAL scale?. I disagree and will add that the use of fossil fuels is the underlying cause and the negatives outweigh the positives by a wide margin.

        We are a very clever and adaptable species. Wildly successful at modifying our environment or adjusting to it. Our increasing use of technology over the centuries has been the major driver in allowing 8 billion of us to make our way in an essentially closed system. A big fish tank. Barring a cataclysm or two the human race will survive. Any changes will be slow to occur over the course of a single human life span. Neither one of us will live to see just how bad/good it gets.

  10. Thanks, Doc.

    I know there will be many that will claim this was nothing more than a Maritime accident. Dust storms are not considered rare in this part of the world.

    But they will have entirely missed the point hammered home here. The way we move goods and supplies across the planet in a ‘just-in-time’ context will increasingly be impacted by the effects of climate change and disruptions to those supply lines.

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