Warmer Yorkshire seas mean better swimming - and climate havoc: Asif Husain-Naviatti

According to the US National Oceanic and Atmospheric Administration British coastal waters have been especially affected, with seas off the English coast measuring up to 5C above normal.

Parts of the North Sea are categorised as “extreme.”

We tend to think more often about surface air temperature over land – or how hot it’s going to feel today. The World Meteorological Association recently announced that a combination of greenhouse gas effects and the naturally occurring El Niño weather phenomenon would lead to new record temperatures during the next five years. It offered a virtual certainty that one of those years would be the hottest ever on record, and a 66 per cent likelihood that such a year would exceed the UN climate threshold of 1.5C above preindustrial averages.

We heard from Europe’s Copernicus Climate Change Service just last week that 1.5C had in fact been breached briefly during the first days of June.

To give perspective, the momentary breach in June observed by Copernicus is different from the WMO prediction, an annual average which has not yet come to pass. Neither can be compared with the longer-term averages spanning usually 30 years, and accounting for intermediate fluctuations, which are cited by such bodies as the International Panel on Climate Change (IPCC) when looking at climate change.

Nonetheless, the June breach is significant, and changes in sea temperature are much more so.

A big problem we have when relating to climate change is a perception that the more catastrophic effects may be at the other side of the world, in the future or under the sea. If we even notice the sharp rise in sea temperatures, it might be welcomed and lead to more trips to the beach.

But there are reasons to be concerned. Every year since 2019, including this one, has seen record breaking sea temperatures. NASA observed that the last 10 years have been the warmest since the 1800s for the world’s oceans.

Better swimming conditions off the north coast is one thing. But there is another side. The warming of the North Sea is affecting important marine resources which are vital to the food chain. The decline of plankton – not exciting to us but devastating if you are a fish – has strong implications for cod, one of the most distinctive of British seaside staples. Fish stocks are already limited due to overfishing.

This illustrates one of the most problematic, but often overlooked, aspects of climate change – the disruption it brings to naturally occurring systems and chains which are highly dependent on each other and may never recover.

Higher sea temperatures also means higher water levels. This is not just a matter of melting ice caps, but because warmer water has greater volume too.

An estimated half of rising sea levels is due to thermal expansion. Parts of the lower-lying Lincolnshire and Norfolk coastline could eventually disappear, as could Filey in North Yorkshire. Meanwhile, expect the higher energy of warmer seas to further batter and undercut our already crumbling cliffs.

At the other side of the world, the global effects can be altogether more devastating and even life threatening. The energy in warmer waters in large parts of the American continents and the Caribbean are fuelling bigger, more damaging and more costly hurricanes. The same is true of cyclones throughout the Asia-Pacific region. Entire small island nations are under threat of complete submersion.

Aside from plankton, warmer waters globally are causing disruption to whole ecosystems, mass migrations of marine species and ocean acidification which is destroying corals and affecting marine biodiversity on a global scale.

The changes in sea temperatures are more telling than on land, because it takes huge amounts of energy to heat up the seas and they don’t cool quickly. And there is such a lot of water in our oceans. At last a practical application for what we all learned in school; that our breakfast toast heats and cools more rapidly than our morning cup of tea!

So if the increases in sea temperatures are prolonged, and indeed at accelerating rates, this is a powerful indicator of climate change in progress. The sea has already absorbed 90 per cent of heat generated by emissions and there is as much heat stored in the top few metres as in the earth’s entire atmosphere. It is a huge carbon sink, often cited as the “lungs of the planet.” It is also one of our most important defences against climate change.

Asif Husain-Naviatti, originally from Rotherham, has over 25 years of experience at the UN, World Bank and other international organisations on sustainable development.