Sea levels have been rising and falling without any help from humans for as long as Earth’s oceans have existed.

The fastest and most alarming sea changes to affect mankind occurred at the end of the Pleistocene Ice Age. Seas rose about 130m about 12,000 years ago, at times rising at five metres per century. Sea levels then fell as ice sheet and glaciers grew in the recent Little Ice Age – some Roman ports used during the Roman Warm Era are now far from the sea even though sea levels have recovered somewhat during the Modern Warm Era.

Many natural factors cause sea levels to rise - melting of land-based glaciers and ice sheets; warming and expansion in volume of the oceans; extraction of groundwater which ends up in the oceans; and sediments, sewerage, plant debris and volcanic ash washed into the oceans by rivers, storms and glaciers. In addition, tectonic forces cause some blocks of land to rise while others fall, hence the paradox of sea levels appearing to rise on one coastline while falling on another.

Currently the world’s oceans are rising at about 1mm per year, which has not changed much with the great industrialisation since 1945. Amongst all the factors moving the restless sea, man’s production of carbon dioxide is obviously an insignificant player.

Sea levels are always changing, at times very destructively. Waves move sea levels by a few metres and at places like Derby, WA, king tides can move sea levels by eleven metres. Then there are rogue waves up to 30 metres high which have sunk oil tankers, and tsunamis which can smash coastlines with a ten metre wall of water moving at over 800 km per hour.

Despite coping with all of the above, climate alarmists say we should be scared to death by the threat of seas rising gently at 1mm per year. Even a slow-moving sloth could escape water rising at that rate.

King Canute showed his nobles that no man can hold back the rising sea. It’s time the climate alarmists learned Canute’s lesson and focussed on real world problems.

Even if we ceased using all carbon fuels for electricity and transport, no one could measure the effect of that huge sacrifice on global sea levels.