Global sea level rise rate speeding up, 25 years of satellite data confirms

The rate of global sea level rise is accelerating as ice sheets in Antarctica and Greenland melt, an analysis of the first 25 years of satellite data confirms.

Satellite data indicates sea levels will rise around 61 cm between now and 2100.

The study, by US scientists, has calculated the rate of global mean sea level rise is not just going up at a steady rate of 3mm a year, but has been increasing by an additional 0.08mm a year, every year since 1993.

If the rate of change continues at this pace, global mean sea levels will rise 61 centimetres between now and 2100, they report today in the journal Proceedings of the National Academy of Sciences.

"That's basically double the amount you would get if you only had 3 mm a year with no acceleration," said the study's lead author Steven Nerem of the University of Colorado.

Read the ABC News story by Genelle Weule - “Global sea level rise rate speeding up, 25 years of satellite data confirms.

New Antarctic heat maps to improve predictions of sea level rise

Previous calculations of heat from crustal rocks beneath ice sheets and glaciers in Antarctica have assumed constant heat emitted from the decay of radioactive elements such as uranium and thorium. But as Tom Raimondo and Jacqui Halpin explain, these elements vary in concentration which leads to variations in heat released under glaciers and ice sheets. More heat means more melting and more slippage of ice. 

Geologist Jacqui Halpin in the David Range
near Mawson Station in the Antarctica. 

Now a new heat map has been produced for the Antarctic Peninsula and work is proceeding to produce more detailed maps for the entire continent. The added detail, some of which can be obtained from deposits in Australia once joined to rocks in Antarctica will enable more accurate predictions of ice melt, a major contributor to sea level rise.

Listen to this story from the Science Show ion Radio National - “New Antarctic heat maps to improve predictions of sea level rise.”

Looming floods, threaten cities

More than 60 percent of the freshwater on Earth is locked in Antarctica’s ice sheets.

Parts of the West Antarctic ice sheet are rapidly losing ice into the sea. Red areas have lost significant amounts of ice since 2010. Blue areas have gained ice.

And because much of West Antarctica’s ice sits below sea level, it is especially vulnerable to ocean heat.

Read the second part of the three-part series on The New York Times - ‘Antarctic Dispatches’ - “Looming floods, threaten cities.”

Here is something new - our poles are on the move!

Every day, it seems, there is something new.

Now researchers have detected that the North Pole is drifting.

NewScientist reports in a story headed: “Earth’s poles are shifting because of climate change”, that subtle changes in Earth’s rotation have resulted from the melting of glaciers and ice sheets.

It has been shown that the melting due to greenhouse gas emissions is making its own contribution to the shift.