Hello and welcome to more or less on the BBC World Service, where you're weekly fix of

figures and I'm Tim Halford.

This week we've been peering into the murky depths and putting down a statistical led

line to get the measure of that most mysterious of places, the ocean.

More specifically we're interested in how the oceans are changing as the multi-pronged

effects of climate change continue to reshape the world around us.

One loyal listener, Joe Otton, was listening to BBC Radio when his interest was peaked.

I was listening to BBC Inside Science when they mentioned in passing that the oceans are

30% more acidic than they used to be.

Like all loyal listeners, Joe's name quizitive sort so he started to have a look online.

I consulted Google and imagined my surprise.

The ocean is actually alkaline and at a pH of 8.1, a bit less alkaline than it used to

be at 8.2.

So what's going on here?

I asked our reporter Nathan Goward to investigate Helen and Nathan.

Hi Tim.

So the first thing we need to do is to re-equaint ourselves with some classroom chemistry.

First of all, we measured the acidity of water using what is called the pH scale.

This is a scale that goes from 0 to 14.

Now when you're at school, you learn that the scale is divided into two sections.

Starting from 0 to 7 is classed as an acid, while anything from 7 to 14 is called an

alkali, or alternatively a base.

...