Some nice seawater...

A Welsh beach in summer, with atypical sunshine.

Well here I am, this is my blog. The ‘gravatar’ is one of my dogs, Hamish, who is much prettier than me.

I am an environmental journalist and have been for some centuries, or so some people think. I write a lot about water, for some rather wonderful publications that somehow put up with me. For that I thank them from the bottom of my crusty old heart.

Like many journalists, I suffer from the vice of Googling myself. This is not yet illegal, though some governments are working on it. Usually, all I find are links to articles I’ve written (which is good) but yesterday I found a webpage which lambasts a small news story on a UN report on oceans and climate change. Not good!

The poor little blameless story, which simply summarises the report’s findings, is lambasted as ‘highly inaccurate’ and ‘climate change brainwash’.

Since the opinion is from a Learned Doctor and I am only a Grumpy Green Granny, far be it from me to argue. But my simple brain cannot quite wrap itself round one of his arguments about seawater entering aquifers (Basically rocks that hold water, like a big rocky sponge. Water utilities pump it up for drinking). Apparently salt water getting into freshwater aquifers is a Good Thing.

The learned chap says, and I quote: ‘any intrusion of seawater into freshwater aquifers raises (not lowers) the freshwater water table. That’s a simple consequence of the physics, i.e. higher density of saltwater compared to freshwater. Therefore, any such freshwater reservoir will not diminish in size or volume by any seawater intrusion, it will just become raised.’

So, as I understand it, he is saying that the heavier seawater will simply push the freshwater up – there will be more water, and it will be closer to the surface and handier for us to reach. Oh deep joy! Break out the furnaces, onward with climate change!

But hang on a tick. I vaguely remember some physics too, or is it cookery? It is to do with mixing. You can test this yourself at home. Mix two tablespoons of salt with 100ml of water. Then add 200ml of freshwater.

Look carefully to see if you can see the helpful saltwater pushing up the freshwater. Take a sip (carefully! I don’t want anyone’s mother writing to me to complain I’ve made their child sick!). Does it taste fresh to you? No, I didn’t think so… And neither will your aquifer. It may take a bit longer, particularly if you don’t use a spoon, but it will happen. Is this a Good Thing? You tell me!

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