Martin Sharp brightly resembles his first flowing stream. He spent this June in the 2007 camping Devon Ice Hat. This gently curved ice dome is 140 kilometers (87 miles) high and has a height of 1,900 meters (6,200 feet). It is located on an island in the High Arctic of Canada.
Sharp had been riding a snowmobile when he heard the worry. It sounded like a subway train rumble. All the snow slides down in front of him: the slow-motion river that was irrigated fell down the hill. The floods of hot, sunny days had melted so much snow that the slope could no longer support itself.
Slush streams didn't happen here. The summers were not warm enough, the glaciologist at the University of Alberta, Canada, noted. But by the time he saw it in 2007, he heard more and more about them. In one unforgettable event, the melted water, which sits up, suddenly drained the ice cap. It sent 10 km (6 miles) down the valley to flood water, leak and ice. It almost destroyed the camp where the scientists were.
Sharp made it a decision. In recent years, he and his colleagues visited the Devon ice hat almost every summer. Continuing, they now come in April or May, when the days were still cool enough to avoid such dangers. "The world has changed," he says.
Devon is one of the thousands of ice ice masses that give the world. Some are narrow ice, called glaciers. They flow out of mountain canyons. Others, such as Devon, are wide, blobby ice caps that cover all islands, exiting the outside.
These icy areas are negligible compared to the three large ice sheets around the world, covering Greenland and the East and West Antarctica. All in all, these small icy areas have only one-hundredth of the world's ice. But because they take up parts of the earth that are warmer than the ice sheets, they melt much faster. They are also currently the main source of sea level rise. In total, they lose about 230 cubic meters of ice per year. Throw all this ice in one big pile, and it could build your own mountain range.
It started when a strong wind belt moved this year. This is called polar jet, it is bent to the north as a sloping snake. Its winds from the Atlantic Ocean to the western edge of Greenland made warm air on the Canadian islands of the Arctic.
Gardner was a doctoral student at the University of Alberta in the late 2000s. He worked with Sharp. He used a satellite to assess how the Arctic Canadian glaciers and ice caps change.
This is called IceSat, and it contained a tool called a laser altimeter. As a satellite in orbit, it shone a laser beam directly on the ground. By accurately measuring how long the beams were taken to fill the Earth's surface and return, IceSat could measure the exact elevation.
IceSat has made several hundred of Canadian glaciers and ice caps. Its data showed Gardner that the ice had begun to throw away – and quickly.
Between 2004 and 2006, these glaciers and ice hats lost about 30 billion tonnes of ice per year. Over time, Gardner found that the speed of ice loss was accelerated. For example, between 2007 and 2009, the same glaciers lost about 90 billion tonnes of ice per year.
By comparing summer temperatures with the amount of ice lost each year, Gardner discovered a staggering fact. For every 1 Celsius degree (1.8 degrees Fahrenheit), which complemented the summer warming, the region lost and an additional 64 billion tonnes of ice per year. This showed that this region has become "incredibly sensitive to a slight change in temperature," he says. He completed his doctorate in 2010 and is now working at Jet Propulsion Laboratory. It is located at the California Institute of Technology in Pasadena.
The Arctic heats up several times faster than the whole world. According to Gardner, Canada's high Arctic will continue to warm up over the next 70 years, as the rate of ice loss can easily double or triple.
But not every mountain glacier and ice cap are experiencing similar warming speeds. This is especially true of the world's highest mountain ranges, says Gardner: "You have all these competitive weather conditions in the mountains of the Asian highlands, which makes it really difficult."
Asian Water Towers
The Karakoram (Kaer-uh-KOR-am) range covers the borders of Pakistan, India, and West China. It is located on hundreds of glaciers and the world's second highest mountain K2. Its maximum reach is 8,611 meters (28,251 feet). Despite rising temperatures and rapid melting, the Karakoram glaciers do not seem to be shrinking. Gardner suspects that higher temperatures can evaporate more water and more mountains on top. These magnified clouds reduce more snow on the glaciers. And this could offset the effects of local melting – at least now.
But the mountains further north, the western Chinese Tien Shan have lost ice quickly. Between 1961 and 2012, their glaciers collectively lost a sixth of their territory – and a quarter of the total ice!
These glaciers are not particularly large. So even if they disappear, they would increase the sea level a little. "But they are of great importance to local people," says Gardner. Tien Shan is one of the examples scientists call "water towers" of Central Asia.
Even during the dry season, these glaciers eat rivers. Millions of people across the region are dependent on these rivers to irrigate their crops when the rain does not fall.
Although very few are exposed to downstream communities, these small mountain glaciers are in some ways more difficult to control than the large Greenland and Antarctic ice sheets. Many satellites that measure changes in ice sheets do not work on small glaciers. Gardner relied on IceSat to follow these glaciers. Its narrow laser radiation was ideal for measuring the height of small ice areas. Unfortunately, in 2009, the satellite stopped working.
It has been difficult in recent years. Without this satellite eyes in the sky, says Gardner, "We've been a little blind lately."
But it should change and soon. On September 15, 2018, NASA launched a new satellite in space. Known as IceSat-2, it will perform even more detailed measurements than its predecessor. As soon as enough measurements are made, Gardner says in a few months' time that it will "provide us with the necessary update".