'Unheard of' heatwave off UK coast poses major threat to marine life
ITV news health and science correspondent Martin Stew reports as global sea surface temperatures have hit "unheard of" highs
Global sea surface temperatures have hit "unheard of" highs, sparking concern among scientists and meteorologists about the impact of climate change on delicate marine ecosystems.
Climate change caused by human emissions, combined with natural phenomena like El Nino, have pushed up ocean temperatures during the spring to a level never before seen since records began in 1850.
Scientists are expecting more records to be broken as the summer advances.
The North Atlantic temperature in May was around 1.25C above the 1961-1990 average – the highest anomaly for any month on record.
The temperature of the north-east coast of England and the west of Ireland has also been several degrees above normal.
The US National Oceanic and Atmospheric Administration has categorised parts of the North Sea as being in an "extreme" heatwave.Antarctic sea ice is also “exceptionally low, the lowest on record for this date by a wide margin”, the Met Office said.
El Nino, and its counterpart La Nina, cycle every few years in the tropical eastern Pacific and produce a warming and a cooling effect respectively on the world’s oceans and atmosphere.
US meteorologists said last week that El Nino has now begun, characterised by a 0.5C rise above the long-term average temperature in the tropical eastern Pacific.
Professor Albert Klein Tank, head of the Met Office Hadley Centre, said airborne dust from the Sahara helps to cool the eastern Pacific by blocking and reflecting some of the sun’s energy but winds have been weaker than average this year.
He added: "It is not believed that these factors represent a climate change-induced tipping point that produces runaway temperatures. However, they will add to climate and weather impacts this year.”
Daniela Schmidt, Professor of Earth Sciences, University of Bristol, said: "While marine heatwaves are found in warmer seas like the Mediterranean, such anomalous temperatures in this part of the North Atlantic are unheard of.
"As long as we are not dramatically cutting emissions, these heatwaves will continue to destroy our ecosystems."
Numerous instances of huge numbers of dead fish and sea birds washing up on shores have been linked to rising ocean temperatures in recent years.
Last week Mexican authorities said El Nino and climate change were to blame for 300 wild birds washing up on their shores.
Earlier in June tens of thousands of fish washed up on Texas' coast, which was blamed on rising temperatures lowering oxygen levels in the ocean.
The Met Office has predicted there will be an above-average number of hurricanes this season because of the warming North Atlantic, despite that number usually falling during El Nino periods because wind shear blows them apart before they can properly form.
El Nino could also be contributing to the Antarctic sea ice record lows this year, along with the Southern Annular Mode – which affects winds in the southern hemisphere – and human-driven climate change.
Dr Ed Blockley, lead of the Polar Climate Group at the Met Office, said: "Antarctic sea ice has been at very low levels since November 2016.
"This year we have seen Antarctic sea ice shrink to a record low-point for the time of year, following a second successive annual record minimum sea ice extent in February."
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