‘Significant’ record rise in sea temperatures in the North Atlantic caused by climate change is a factor, says Met ÉireannAfter a very warm and dry June in 2023, it began to rain heavily in July and the trend has scarcely stopped since. Photograph: Nick Bradshaw/The Irish Times. It then began to rain heavily in July and the trend has scarcely stopped since. The rest of summer 2023 was a wash out.
In addition, there has been precious little drying with just 50 per cent of the expected sunshine for the month recorded. The long-term average North Atlantic sea temperature is at 19.2 degrees but, according to the US government’s National Oceanic and Atmospheric Administration , sea temperatures are now at an average of 20.4 degrees, up 0.4 degrees on last year’s record levels.
One theory as to why the North Atlantic is heating up is a ban on marine vessel using fuel that contains sulphur, which has a cooling effect on the atmosphere by reflecting sunlight. This ban was introduced in 2020 and has had unintended consequences, but Moore stresses that its impact on temperatures is likely to be small.