Just how much ice has been lost from the world’s ice caps and land ice? A new study from the University of Colorado has used NASA satellite data to find out.
Using information from NASA’s Gravity Recovery And Climate Experiment satellite measurements, the Colorado researchers determined ice lost from the Earth’s land between 2003 and 2010.
It found the total ice lost, particularly from Greenland and Antarctica, was 4.3 trillion tonnes over the seven year period, adding around 12 millimetres to our global sea level.
“Earth is losing a huge amount of ice to the ocean annually, and these new results will help us answer important questions in terms of both sea rise and how the planet's cold regions are responding to global change," Professor John Wahr, a leader of the study in a NASA press release.
Scientist Tom Wagner says that the amount of ice that has melted is below initial estimates, but still has significant implications for future rises in sea level.
“Ice is being lost from around the globe, with just a few areas in precarious balance. The results sharpen our view of land-ice melting, which poses the biggest, most threatening factor in future sea level rise," he said in the NASA release.
To measure the changes in glacier size and how much ice is melting, the GRACE spacecraft track changes in the Earth’s gravitational field caused by variances in the mass of the Earth, which are generally caused by the movement of water on the surface of the Earth.