According to the World Meteorological Organization, June and the first few days of July were the hottest on record.
Residents of the southern United States and southern Europe have suffered from oppressive temperatures, numerous heat warnings, wildfires and sharp deterioration in air quality.
Records were not only broken on land, but also in the water.
Getty Images In particular, the water temperatures around Florida were particularly warm in June.
The Global sea surface temperatures were higher According to a report by the Copernicus climate change service, June was higher than any on record, with satellite readings for the North Atlantic being particularly high.
Last month, a record was also set at the National Office of Oceanic and Atmospheric Administration (NOAA) for the largest difference between expected and actual temperatures.
The water temperatures around Florida in particular were particularly warm.
Researchers have also observed an ongoing major marine heatwave off the west coast of the US and Canada that formed in May.
According to the scientific non-governmental organization Mercator Ocean International, while the heat wave in the north-east Atlantic has now subsided, another in the western Mediterranean appears to be intensifyingparticularly around the Strait of Gibraltar.
Getty Images
Extreme sea temperatures have also been observed around Ireland, the United Kingdom and the Baltic Sea, and in areas near New Zealand and Australia. Most recently, scientists suspect a possible heat wave south of Greenlandin the Labrador Sea.
“We have these huge marine heatwaves in different parts of the ocean, developing unexpectedly very early in the year, very strongly and over large areas,” says Karina von Schuckmann, oceanographer at Mercator Ocean.
“Without Precedents”
Carlo Buontempo, director of the European Union’s Copernicus Climate Change Service, scientists say Expect large temperature swings in the Pacific Oceanlinked to the El Niño weather pattern, a phase of global warming that is just beginning, although NOAA has been tracking a major heatwave in the Gulf of Alaska that has been offshore since 2022.
But what we are currently seeing in the North Atlantic is really the case “unprecedented”says Buontempo.
Scientists are still trying to elucidate all the causes.
Short-term changes in regional oceanic and atmospheric circulation patterns can set the conditions for periods of intense ocean heat lasting weeks, months, and even years.
But long-term increase The increase in sea temperatures due to an increase in greenhouse gas emissions is a key factor behind the recent heat waves.
European Union/Copernicus The North Atlantic and Mediterranean have experienced record temperatures in recent months.
Near 90% excess heat caused by anthropogenic climate change stored in the oceanand over the past two decades, the rate of heat accumulation in the Earth’s climate system has doubled.
A 2021 report by the Intergovernmental Panel on Climate Change (IPCC) found that the frequency of marine heatwaves had doubled between 1982 and 2016, and a tipping point was occurring more intense and longer since the 1980s.
Another possible factor is the amount of aerosols in the atmosphere, which have a slight cooling effect. However, this seems to have declined due to attempts at restructuring in the shipping industry.
Something unusual happened recently Lack of Saharan dustwhich usually leads to cooling.
everything can be worse
Today’s heat waves in the sea can even deteriorate. While experts don’t believe that El Niño itself caused the event in the North Atlantic, the WMO believes it will contribute to warming of the oceans in general.
Experts fear that heat waves in the sea could have an impact on the environment Ocean life, fisheries and weather conditions.
Getty Images Heat waves at sea can have a serious impact on fisheries.
Record high temperatures off the west coast of Australia in the summer of 2010/2011 led to a “devastating” fish kills And destroyed kelp forests, and fundamentally changed the coastal ecosystem.
A few years later, an unprecedented ocean heatwave caused by climate change and exacerbated by a strong El Niño resulted in the worst coral bleaching Seen on the Great Barrier Reef in 2016.
Ocean heat waves can trigger coral bleaching and have already put additional stress on coral reefs. reef ecosystems Worldwide.
High temperatures can cause coral polyps to expel the zooxanthellae living in their tissues, turning them white and making them more susceptible to disease and other threats.
In the Mediterranean, exceptional temperatures between 2015 and 2019 repeatedly led to mass deaths of important species such as corals and algae. A recent study described marine heatwaves of this type as “ubiquitous stressors on global marine ecosystems.”
Getty Images The heat of the water leads to bleaching of the corals.
Marine heat waves also favor the spread of invasive species.
Japanese seaweed, for example, proliferated in New Zealand when a 2017-2018 marine heatwave in the Tasman Sea wiped out the native seaweed.
much to learn
So says Dan Smale, marine ecologist at the UK Marine Biological Association and member of the International Task Force on Marine Heat Waves “short and quick punches” They don’t give species time to redistribute, and those species that are at the limit of what their bodies can support are particularly at risk.
But even on Britain’s coast, which is not considered extreme environments and where scientists expect ecosystems to gradually change, a marine heatwave could prove deadly if it lasts through the summer.
However, there is still much to be learned about the impact of marine heatwaves compared to heatwaves on land, as monitoring them is more difficult and long-term records are lacking, says Smale.
“The information that satellites have been giving us since the early 1980s is fantastic…the problem is when we try to go further,” he says.
warm oceans for a while
A significant decrease in the number phytoplankton It has already been observed in the North Atlantic, attributing Mercator Ocean to recent heat waves.
Getty Images The heatwave is helping to spread invasive species.
Spring flowering is critical as it provides most of the energy needed to sustain the region’s marine food chain and is a major contributor to global oceanic CO2 uptake.
The economy of regional fisheries could also be affected.
A 2012 Northwest Atlantic heat wave caused species that prefer warmer waters to head north and migrate early, changing when and how much catch was possible.
The North Atlantic is also a major driver of extreme weather conditions.
Increased sea surface temperatures can lead to this hurricanes, However, it remains to be seen whether the El Niño phenomenon will amplify or mitigate this effect next year.
On the other hand, the warmth of the North Atlantic water is the most important factor in the alternating cycle between sDroughts and heavy rains in Central Africa.
Overall, experts say the persistence of recent ocean heatwaves is a worrying sign of how climate change is shaping up along with onshore heatwaves, unusual melting of Himalayan snowpack and loss of sea ice.
Von Schuckmann says that even if people stopped pumping CO2 into the air tomorrow, The oceans would continue to warm for several more years.
“As a climate scientist, I worry that we are further away than we thought.”
BBC
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