First direct evidence that human activity is linked to Antarctic ice shelf collapse

Scientists from the British Antarctic Survey (BAS), the Centre for Polar Observation and Modelling, University College London, and the Katholieke Universiteit Leuven, (Belgium) reveal that stronger westerly winds in the northern Antarctic Peninsula, driven principally by human-induced climate change, are responsible for the marked regional summer warming that led to the retreat and collapse of the northern Larsen Ice Shelf.

Global warming and the ozone hole have changed Antarctic weather patterns such that strengthened westerly winds force warm air eastward over the natural barrier created by the Antarctic Peninsula's 2 km-high mountain chain. On days when this happens in summer temperatures in the north-east Peninsula warm by around 5 degrees C, creating the conditions that allowed the drainage of melt-water into crevasses on the Larsen Ice Shelf, a key process that led to its break-up in 2002.

Lead author Dr Gareth Marshall from the British Antarctic Survey said, “This is the first time that anyone has been able to demonstrate a physical process directly linking the break-up of the Larsen Ice Shelf to human activity. Climate change does not impact our planet evenly – it changes weather patterns in a complex way that takes detailed research and computer modelling techniques to unravel. What we've observed at one of the planet's more remote regions is a regional amplifying mechanism that led to the dramatic climate change we see over the Antarctic Peninsula.”