NASA-funded expedition to Greenland to collect evidence demonstrating that that the emerging melt lakes and rivers above Greenland's Ice Sheet are a direct link to climate change. American glaciologist Jason Box and Australian polar explorer John Hoelscher use surveying equipment to estimate the volume of melt water in the lakes over the ice sheet by determining the relationship between the depth of the lakes and it's shade of blue. The volume of water is important because it plays a role in accelerating the movement of the ice sheet, this is turn affects sea level rise as the ice flows towards the coast and into the sea.