When all the ice melts

Pan fydd yr holl iâ’n toddi, bydd y môr yn cyrraedd fan hyn
When all the ice melts, the sea will be up to here

When all the ice on earth melts, the average level of the sea will be around 200 feet higher than it is now.

It will take thousands of years for the sea to deepen by 200 feet (which it will if the Earth’s temperature continues to increase). About five thousand years seems to be the timescale.

Five thousand years, you say? Way too big a stretch of time to think about. But there were people like you and me living five thousand years ago, with writing and money and organised religion and civil engineering and agriculture and  beautiful art.

Think of a 200-foot depth of water inching its way upwards, slowly, deepening relentlessly. I live beside the sea, and this is what I’ve been thinking about recently. Indeed, I live next to a large swathe of low-lying land that was sea 220 years ago.

About a month ago I started cycling and walking to points near me where roads and public rights of way cross the 200-foot contour, and pinning up a PostIt note saying:

Pan fydd yr holl iâ’n toddi, bydd y môr yn cyrraedd fan hyn.
When all the ice melts, the sea will be up to here.

In each of these photos there’s a PostIt pinned to something, saying the same thing:

Pan fydd yr holl iâ’n toddi, bydd y môr yn cyrraedd fan hyn.

When all the ice melts, the sea will be up to here.

This is a useful interactive map to look at the result of different heights of sea level rise. For +200 feet, use a rise of 61 metres.