Rise in global sea levels could have 'profound consequences’

Scientists believe that global sea levels could rise far more than predicted, due to accelerating melting in Greenland and Antarctica.

A small boat in the Illulissat Icefjord in western Greenland,
dwarfed by icebergs that have calved from Greenland's largest glacier, 

The long-held view has been that the world's seas would rise by a maximum of just under a metre by 2100.

This new study, based on expert opinions, projects that the real level may be around double that figure.

This could lead to the displacement of hundreds of millions of people, the authors say.

• Antarctic instability 'is spreading'
• Thousands of penguin chicks wiped out
• Warning from 'Antarctica's last forests'

The question of sea-level rise was one of the most controversial issues raised by the Intergovernmental Panel on Climate Change (IPCC), when it published its fifth assessment report in 2013.

Read the BBC story by Matt McGrath - “Rise in global sea levels could have 'profound consequences’.”

Seas aren’t just rising, scientists say — it’s worse than that. They’re speeding up

North Miami buildings are
seen near the ocean.

On a warming Earth, seas inevitably rise, as ice on land melts and makes its way to the ocean. And not only that — the ocean itself swells, because warm water expands. We already know this is happening — according to NASA, seas are currently rising at a rate of 3.5 millimeters per year, which converts to about 1.4 inches per decade.

However, scientists have long expected that the story should be even worse than this. Predictions suggest that seas should not only rise, but that the rise should accelerate, meaning that the annual rate of rise should itself increase over time. That’s because the great ice sheets, Greenland and Antarctica, should lose more and more mass, and the heat in the ocean should also increase.

The problem, or even mystery, is that scientists haven’t seen an unambiguous acceleration of sea level rise in a data record that’s considered the best for observing the problem — the one that began with the TOPEX/Poseidon satellite, which launched in late 1992 and carried an instrument, called a radar altimeter, that gives a very precise measurement of sea level around the globe. (It has since been succeeded by other satellites providing similar measurements.)

Read The Washington Post story - “Seas aren’t just rising, scientists say — it’s worse than that. They’re speeding up.”