Glaciers of the world are down 9,000 billion tonnes of ice over the last half century

Things are not going well for the glaciers of the Earth. Usually, with respect to climate change and ice melt, we think of the polar regions of the Earth. But these are not the only important ice formations, nor the only ice that melts because of climate change.

A new study published on April 8, 2019 shows that glaciers on Earth have lost more than 9,000 gigatons of ice since 1961. That's more than 9,000 billion tons. As a result, they have caused the sea to increase 27 mm (1.06 inches) since then.

The research comes from an international team led by scientists from the University of Zurich, Switzerland. They relied on measurements of glaciers, taken from the ground and satellites, over the past 50 years. They focused on 19 glacial regions around the world, including Alaska, Greenland and the Andes.

The European Space Agency (ESA) Climate Change Initiative is at the heart of this research. This program collects important data on climate change and organizes it, archives it and makes it available to researchers. ITC has a glacier monitoring program that provides researchers with glacier outlines and information on the ice mbad evolution of thousands of glaciers around the world.

Frank Paul, of the Geography Department of the University of Zurich, and co-author of the study, said this in a press release: "Glacier outlines are needed to perform accurate calculations for areas in question. To date, much of this information comes from the US Landsat satellites, whose data are transmitted to European users as part of the mission agreement between ESA and ESA. In the future, the Copernicus Sentinel-2 mission, in particular, will contribute more and more to the accurate monitoring of glacier change. "

This study is based on a multitude of data sources. The ASTER sensor from the Japan Aerospace Exploration Agency for the US Terra mission and the German TanDEM-X mission were at the forefront. Their data was used to build Digital Elevation Models (DEMs), which provide 3D topographic details of a region.

"We are currently losing a total of 335 billion tonnes of ice a year, corresponding to a rise in sea level of almost 1 mm per year. "

Michael Zemp, Department of Geography, University of Zurich.

All these data were combined with the complete glaciological database established by the Global Glacier Monitoring Service. It has been used to replenish the changes in ice thickness for more than 19,000 glaciers in the world. This is how researchers reached the figure of 9,000 billion tons.

Michael Zemp, from the Geography Department of the University of Zurich, was the head of research in this study.

"Although we can now provide clear information on the amount of ice lost in each region with glaciers, it is also important to note that the rate of loss has increased significantly over the past 30 years. We are currently losing a total of 335 billion tonnes of ice a year, which corresponds to a rise in sea level of almost 1 mm per year. "

"In other words, every year we lose about three times more ice than all the ice stored in the European Alps, which is about 30% of the current rate of sea level rise" Zemp added.

Glaciers and ice caps are the largest source of fresh water in the world. But it is the glaciers that release their water into human communities. Reducing glaciers means less water for people, less water for irrigation and less water for hydroelectric power generation. And then, of course, there is wildlife.

All of this means that critical decisions and planning choices must be made, and they must be well planned in advance. That's what these data are supposed to help. Only accurate, long-term data can be used to plan climate change effectively.

"It is fundamental that we build on existing surveillance capabilities using observations from the EC's Copernicus Sentinel missions and other ESA missions and third-party missions. Their data allows us to build a robust climate outlook that reveals regional and annual fluctuations in glaciers and other parts of the cryosphere, such as snow cover, sea ice and ice sheets, "said Mark Drinkwater, Councilor main for the cryosphere and the climate at ESA.

"Taking into account the socio-economic consequences, ESA seriously considers the fate of glaciers in a future climate."

On a personal note

I doubt that many readers of Univers Today are so skeptical about climate change. There is a lot of evidence to support it. Sometimes the evidence is not scientific, but personal.

In the city where I grew up here in Canada, and in the city where I still live at the age of 52, we have our own glacier. It is perched in the mountains, very visible day after day, year after year, for all those who wish it. It is even a hiking destination for those who are sufficiently prepared and experienced to travel to the hinterland.

A very complete and distributed photographic record of the retreat of this glacier during the last decades. I bet everyone who lives here or has been there has taken photos. It's a breathtaking show, an icon of our community.

As we experience increasingly hot and dry summers and smoke from distant forest fires cover our region for several weeks at a time, we can watch our glacier retreat, see it through the smoke and ask when climate change will really take seriously as a society.

It's not just a pretty landmark. This glacier is part of our watershed and releases water throughout the summer, which helps maintain the viability of our community. It also powers our hydroelectric system and maintains viable salmon populations in local rivers. Glaciers perform the same function worldwide, in some of the most populous regions of the world. How will communities work without them?