calcite cluster at Fall Bay, south Gower
Wandering the coastline of Gower I’m drawn to the unassuming, sometimes grubby looking, white stuff welded amongst the limestone rock - because it is a mineral with a secret. This is Calcite, the crystalline form of calcium carbonate, which has invisible yet strong links to Antarctica via global warming.
Calcium carbonate in the form of limestone (rock) and calcite (crystal) is one of the most commonly found substances on the planet. It is a mineral universally used on an industrial scale and therein lies its secret (if you missed the clue in its name). It is in fact a carbon sink, or in other words, it keeps its carbon locked within it - inert and largely unable to move (except for the slow wearing away by sea, wind and rain over millennia).
Then we came along and invented cement. And to make that cement we use vast quantities of calcium carbonate. We not only dig it out of the earth, we also crush it and roast it. Which releases its carbon into our atmosphere in monumental amounts whilst voraciously consuming energy (often coal) in the process.
Cement manufacture is responsible for "about 8% of the world's carbon dioxide (CO2) emissions, according to think tank Chatham House.”
“If the cement industry were a country, it would be the third largest emitter in the world - behind China and the US. It contributes more CO2 than aviation fuel (2.5%) and is not far behind the global agriculture business (12%).” (https://www.bbc.co.uk/news/science-environment-46455844)
A sobering thought.
So Calcite is present on Gower in its natural, physically benign state and in its industrially processed state. Consequently, it’s also present in the atmosphere here as it is around the world. Its carbon is released by us and, when fettered insufficiently, this contributes exponentially to increasing the atmospheric greenhouse gasses responsible for global warming. With this leading to the depletion of the earth’s ice and an increase in sea level globally……it will inevitably have a direct impact here on the Gower coastline.
calcite veins at Pobbles Bay, south Gower
this colourful mix containing calcite resembles marble!
calcite in an uplifted bedding plane at Broughton beach, north Gower