Number of the Week: 2070

That's the year when an important species of reef-building coral could stop growing in the Red Sea, according to a recent study published in Science.

Diploastrea heliopora growth has declined by 30% since 1998.

Co-author Anne Cohen told the BBC:
"The coral is an animal, and the colony made up of millions of tiny, little animals - and they together build this huge thing that is seven metres in diameter".

"As they are growing, they are building this calcium carbonate skeleton that the animal is basically leaving behind. If you cut through a colony, only the very top layer is actually living - the rest of it is all dead".

The team of scientists used a CT scanner to examine the growth rings in the coral and say that at sea surface temperatures above 30.5C, the growth rate of the coral plummets.

Using future climate change scenarios, the team calculated that the coral would cease growing entirely, if these climate change predictions were accurate, by 2070 (see graph below).