An image of the Columbia glacier taken from the Sentinel-2 satellite

© ESA / Eyevine

On 5th August 2017 the Sentinel-2B satellite logged an image of the Columbia glacier, between the slopes of the Chugach Mountains in South Eastern Alaska.
In the last 30 years, this tidewater glacier has retreated 20 metres and has lost half of its total thickness and volume because of global warming.
The Earth's ice cover is deteriorating rapidly. The Arctic region is the zone which has heated up the most, leading to sea ice disappearing at a much faster rate than proposed by climate modelling. This acceleration is worsened by a cycle of chain effects: most of the sun's light is normally reflected by the poles and is not absorbed to be turned in to heat, as instead happens on land, where reflection is lower. Increasing temperatures cause a reduction in ice cover and lowering of reflection while continuous absorption of solar radiation by land is leading to a further increase in global temperatures with repercussions on the entire system that contribute to the melting of glaciers.
The melting of the Arctic and Antarctic zones has led to the loss of about 300 billion tons of ice annually, increasing sea level by about 1.4 cm. Besides diminishing populations of local fauna, like the Antarctic penguin, there will also be marked changes to ocean currents, winds and rainfall in temperate and tropical zones that also affect the human population.
Even if humankind tries to slow global warming, it will be hard to reverse many of the processes already triggered, like rising sea levels or glacial melting.

Valentina Stefani