Rising sea levels are a concern to us all. Well ok, not all of us, but those of us who live in London (which almost makes it OK in my book).

Up until now global warming and polar ice cap melting has been blamed – but now I present a radically different theory based on my own observations…

Ships.

Big Ships.

Really chuffing huge ass Ships.

Have you seen the size of some of those container ships? Here’s some numbers to convince you:

• The QE2 weighs 148,528 BRT but displaces 80,000 tons of water[1]
• The density of sea water is 1.025 g/mL [2]
• The volume of all the oceans is 310 million cubic metres [3]

From this we can calculate (or just plain know) that 1 cubic metre of sea water weighs about a ton ish…henceforth the QE2 displaces 80,000 cubic metres of sea water. So as a percentage of the size of the ocean this is:

(80,000 / 310,000,000) * 100 = 0.0258064516 [4]

But that’s only one ship, there are at least 7,000 container ships [5] – we’ll assume that the QE2 is twice the size of a container ship here (which is probably and underestimate).

This would bring the percentage up to a staggering 90.3225806% [6] increase in the volume of water in the oceans! And that’s only counting the really big container ships – not all the cruise ships and other types! And ferry’s! And dinghy’s!

So in conclusion global warming – yes, but; also big ships!

Seriously though, I hope I’ve made some massive miscalculation here – otherwise it’s pretty worrying!

*** UPDATE ***

Ok it’s only been up 10 mins but Em has highlighted an issue seen clearly [here]

So there’s a bit more than 310 million cubic metres…so what does that do to the final calculation you say? This:

4.08663947 × 10^-8 % [7]

But I’m still not sure about the 7000 ships bit…

** UPDATE 2 **

After reading [this story from the BBC] I’ve recalculated the %age as: 5.25425075 × 10-7% increase in the volume of water in the ocean