For many people, 2023 – confirmed by NASA as the hottest year on record – was marked by extreme weather, blistering heat waves and forest fires. Climate scientists were also alarmed a viral graph on social media showing how far the North Atlantic sea surface temperature deviated from the historical average.
The map was first shared in April by Dr Thomas Smith, associate professor of environmental geography at the London School of Economics, and was one of several, also alarming, illustrating that ocean surface temperatures had reached record highs – and are showing no signs of decline.
This is so unusual. That’s a *huge* amount of energy transferred to the atmosphere. Expect extreme temperature and storm records. The top few meters of our oceans alone store as much energy as the entire atmosphere. I’m very worried about later this year in 2024. https://t.co/7rfyJeZMaA
—Dr. Thomas Smith 🔥🌏 (@DrTELS) April 24, 2023
Increases in sea surface temperature (SST) are important, as the U.S. Environmental Protection Agency puts it, because they could have “profound consequences” for the global climate. They can lead to an increase in the amount of atmospheric water vapor over the oceans and, in turn, an increased likelihood of extreme weather events such as heavy rain and snow.
In addition, they can shift storm tracks, potentially contributing to droughts in some areas, and prolong the growth of bacteria, which can contaminate seafood and cause foodborne illness.
In fact, the Bulletin of the Atomic Scientists on Tuesday cited SST as one of the reasons why their “Doomsday Clock” is still as close to midnight as it has ever been.
On January 21, 2024, Dr. Smith shared an update on his viral post from 2023, in which he said: “This tweet went viral and made headlines in June 2023, two months after my initial concerns about sea surface temperatures.”
He then shared this updated version of the map, which is not pleasant to look at.
“Seven months have passed since then and the North Atlantic has now broken daily SST records for 321 consecutive days. This year has shown no signs of improvement, with new data for 2024 showing a continued pattern of record-breaking temperatures,” added Dr. Smith added. .
So why have records been broken so consistently in 2023 and 2024?
Last year, El Niño – a climate pattern that occurs every two to seven years – caused a rise in surface air temperatures, and a high-pressure system over the Atlantic Ocean will have made a difference.
However, Dr. Smith says there may be another factor at play that he and other scientists say has been overlooked for decades.
He told Yahoo News UK this week: “In recent years it seems that a lot more sunlight is being absorbed by the surface of the ocean. This coincides with changing regulations around fuel shipping, and I think it would be wise not to ignore that coincidence.”
The decision taken in 2020 to clean up international shipping by reducing sulfur oxide emissions was made to improve air quality and protect people’s health from this dangerous gas. Dr. However, Smith warns that this could have had an unintended impact on climate change, which was ‘masked’ for years.
‘We know that aerosols – particles in air pollution – are important for reflecting sunlight. [They] are also important for the formation of clouds, which reflect sunlight into the lower parts of the atmosphere.” This means, he says, that such pollution has likely “helped keep us cooler than we otherwise would have.”
“This was a much bigger effect in the 1950s and 1960s, when industry and transport were much more polluting than today, and we think this may have slowed greenhouse gas warming by several decades before we started cleaning up the atmosphere .
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“But once we start clearing the atmosphere of particulate pollution, it is the warming effect of carbon dioxide that begins to dominate the global temperature pattern.”
While there is no unanimous scientific consensus on this potential phenomenon, Dr. Smith points to a 2023 study published in Oxford Open Climate Change that describes this struggle between less air pollution and more warming as a “Faustian bargain.” The paper suggests that the decline in aerosol emissions since 2010 should accelerate warming, meaning we could reach 2 degrees Celsius above pre-industrial levels by 2050.
“Of course we desperately want to avoid that by 2100, so if that happens before then we could be in for some extreme weather,” says Dr Smith. He warned that reaching 2C by mid-century would be “much faster than most governments plan”.
How could we get out of this?
The best option is to reach net zero as quickly as possible, says Dr. Smith, adding: “It’s really important to understand that the long-term problem here is greenhouse gases.”
Others believe another possible solution is geoengineering, something Dr. Smith emphasized and does not endorse. “That could include reintroducing particles into the ocean atmosphere, but perhaps also cleaner particles such as salt crystals. So using a fine ocean spray to help create clouds that have disappeared due to the cleaner fuels.”
He says “more extreme” options include placing aerosols in the stratosphere, similar to a volcanic eruption, which could contribute to temporary cooling. “There are those again advocating for continued spraying of the stratosphere with these reflective items to offset global warming and buy us some time to reach net zero.”
Ultimately, Dr. Smith that we all need to make decisions as individuals to reduce our carbon emissions, and that governments need to introduce carbon taxes to help fund offsets. “There is very little incentive for people to reduce their carbon footprint.” he adds.
‘More than just an inconvenience’
When asked what we can expect in the worst-case scenario, where global temperatures rise above 2 degrees Celsius by mid-century, the worst-case scenario is a worrying picture.
“Your main concern should be food and water safety,” explains Dr. Smith. “This is why people should worry about two degrees Celsius of warming. We’re not talking about discomfort.
“We are talking about whether you can buy food in the supermarket or whether clean water comes from the tap. We already have problems with a warming of one degree Celsius in some places. We could see a loss of 30-40% of the ‘ the world’s carbohydrate production by 2.5 degrees Celsius.”
Dr. Smith isn’t the only one saying this. A recent NASA study warned that if temperatures continue to rise above 2 degrees Celsius, we could face a multitude of problems at once. “The escalating impacts of all climate extremes examined could cause significant damage to communities and economies, due to fires, floods, landslides and crop failures that could result,” the report says.
Parliamentary research also warns that climate change means that “frequent and severe extreme weather events are expected to increase ‘forced displacement’, and the ‘slow-onset’ impacts of climate change are expected to make the worst-affected regions uninhabitable”.
Dr. Smith adds, “We’re not talking about small changes you might need to make. It’s essentially about whether you can buy food in an economy that depends on imports. “I’d prefer if we didn’t get to that point… I’d prefer if we kept our security, and part of that includes mitigating climate change as quickly as possible.”