IRELAND HAS EXPERIENCED an event unprecedented in recorded history: a category four extreme marine heatwave in our waters.

Water temperatures around Ireland – in particular off the northwest coast – were between four and five degrees higher than normal. Temperatures continue to be far higher than normal for this time of the year.

Oceans play a crucial and sometimes under-appreciated role in regulating the Earth’s climate, acting as essentially a heat sink and taking the edge off rising global temperatures.

Marine life is also highly sensitive to temperature changes, leading to implications for both food security and the potential for the introduction of non-native species migrating northwards into Irish waters in search of cooler temperatures.

So what does this heatwave tell us? Can we point the finger of blame at the El Niño climate pattern, or is this the oceans sending a climate signal of distress?

Presenter Laura Byrne is joined on this week’s episode by Lauren Boland, reporter with The Journal and author of our climate newsletter Temperature Check, and Dr Gerard McCarthy, oceanographer working with Maynooth University’s ICARUS climate unit.

They examine the impact of the heatwave, what it means for marine life, and look at wider oceanic climate trends impacting Ireland, such as an increasingly unstable Gulf Stream.

The Explainer / SoundCloud

This episode was put together by presenter Laura Byrne, senior producer Nicky Ryan and executive producer Sinéad O’Carroll.

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