Say Anything Blog

Actually, that’s the take home message in this article that slams the latest IPCC report for failing to take into account, among other things, the effect of the melting ice in in the western Antarctic ice field on the sea level.

Since the ice field in question is floating in the ocean (instead of e.g. sinking), melting this ice will have a negligible effect on the sea level.

A physics explanation follows:

• Since the ice sheets are floating on the ocean, the buoyant force exerted upon them by the ocean is equal to their weight.
• Archimedes Principle states that the buoyant force on an object is equal to the weight of the water displaced.
• This means that the ice sheet floating on the surface has the same weight as the water it’s displacing.
• Since it has the same weight, once it melts, it has the same volume as the water it was displacing before it melted.
• Ergo, the height of the water is the same with ice floating in it, as it would be immediately after the ice melts [assuming the same water temperature before and after, no evaporation and all of the other usual physics caveats].

I guess this shows that understanding basic physics isn’t a prerequisite for making you the world’s expert on global climate change.