By Ellen Stofan, NASA Chief Scientist
The sky was bright blue and the sun was shining, but the temperature outside was about -38°C (-36°F).
Two days ago, I was flying 2000 feet above the Fountain Ice Stream in Antarctica with Operation IceBridge, NASA’s airborne instrument platform that studies the Arctic and the Antarctic. The IceBridge team was in the Arctic this spring, measuring sea ice thickness and extent, and the elevation and thickness of the Greenland ice sheet.
Now the DC-8 aircraft is based in Punta Arenas, Chile, for about two months, flying carefully-chosen tracks across the Antarctic continent when the weather allows. The science instruments on the aircraft – radars and lidars – measure the height and thickness of the ice sheets, glaciers and ice shelves. NASA has been collecting this data for years, and combining it with data collected by the National Science Foundation, NOAA, and our international partners to see how these critical parts of our climate system – the polar ice caps – are changing.
The polar ice caps play a critical role in climate, as their white surfaces reflect heat and light from the sun. This is especially important in the Arctic. When sea ice disappears it is replaced by the dark ocean surface, which absorbs heat and warmth.
Meanwhile, ice sheets – several kilometers thick in some places – top the Antarctic continent and Greenland. Global temperature has risen due to human-induced climate change over the past several decades, but it has not risen uniformly in all places.
Warming has been accentuated in the Arctic and in the western part of Antarctica. In the West Antarctic, scientific data, including that from IceBridge, tells us that the ice sheet is collapsing and glaciers have accelerated towards the ocean, due to climate change.
But does what happens in a remote region like this really affect us? The answer is unfortunately yes. Collapse of the West Antarctic ice will possibly contribute as much as 30 cm (about 12 in) of sea level rise by 2100.
As I looked out the window at the seemingly endless expanse of white cracked and windblown ice below me, it was hard to think of tropical islands being inundated and tidal surges causing regular flooding in Florida and other US states.
But climate change is happening now, and ice loss here in the Antarctic and in the Arctic is already affecting people all over the world. I have seen it with my own eyes. The amount of warming humans have caused by putting greenhouse gases into our atmosphere will at this point result in some amount of West Antarctic ice sheet collapse, extensive ice loss in Greenland, and a smaller and smaller amount of Arctic ice each summer resulting in irreversible sea level rise and more extreme weather events.
Looking out at the pristine Antarctic ice, I hope that we can start to become better stewards of our planet, and prevent even more irreversible loss of polar ice and resulting sea level rise that will imperil our planet, and its inhabitants.
Dr. Ellen Stofan was appointed NASA chief scientist on August 25, 2013, serving as principal advisor to NASA Administrator Charles Bolden on the agency’s science programs and science-related strategic planning and investments.