source : www.miragenews.com
Based on the most comprehensive monitoring of Greenland’s glaciers to date, Danish researchers have managed to put aside any doubts about the impact of climate change on the planet.
Their new results document that, compared to the 1980s and 1990s, when glaciers shrank on average by about five meters per year, melting has increased fivefold over the past two decades, so that today 25 meters are lost per year.
The new study shows the response of Greenland’s glaciers to climate change over a period of 130 years. The past twenty years are particularly striking, because melting has increased even more dramatically during this period.
The study was published today in the scientific journal Nature Climate Change.
A number of studies in recent years have shown that Greenland’s largest glaciers are under enormous pressure due to climate changes and rising temperatures. However, doubts remained about the extent of the melting glaciers, of which there are c. 22,000 in Greenland, partly due to inadequate measuring methods. But all doubts that existed before have now been dispelled by the Danish researchers.
“In this article we make clear that Greenland’s glaciers are all melting, and that developments have been exceptionally rapid over the past twenty years. There is no longer any doubt about its magnitude and actually no reason to investigate the claim further,” says Assistant. Professor Anders Bjørk from the Department of Geosciences and Natural Resources Management.
200,000 aerial photographs from the Danish National Archives
According to the researcher, previous doubts were justified to some extent. Before the age of satellite imagery, the ability to investigate and document the extent to which glaciers melted over extended periods of time was limited.
For example, only one of Greenland’s approximately 22,000 glaciers was continuously monitored using so-called mass balance measurements, which began in the mid-1990s. At the same time, parts of Greenland were covered by glaciers that seemed untouched by rising temperatures just a few years ago.
“Previously, for example, we saw areas in northern Greenland lagging behind and melting less compared to the hardest-hit glaciers. This created some doubt about the severity of the situation in these areas. At the same time, no one before We had ever shed light on such a long period of time, which also raised doubts. But now the picture is convincing: the melting of all glaciers is in full swing, there is no longer any doubt,” says Anders Bjørk.
To get a complete overview, the researchers closely studied 1,000 of Greenland’s glaciers, a representative number for the entire country. They tracked the melting of glaciers over the past 130 years using satellite images and 200,000 old aerial photographs from the Danish National Archives, which were previously used to make maps.
“Just over 1,000 glaciers is a huge number to study, but we did this because we simply wanted to be absolutely sure that we would get a comprehensive picture of developments over the past 130 years,” says Anders Bjørk.
About the study
- Combined with satellite observations, the researchers used an unused archive of aerial photographs to document the development of more than 1,000 land-locking glaciers in Greenland.
- The researchers’ observations cover all major regions of Greenland over a 130-year period and make it possible for the first time ever to estimate the extent of glacier retreat in the 21st century, across Greenland, within the 130-year timescale to document. .
- Over thirteen decades of observation, scientists have observed significant and widespread retreat among Greenland’s glaciers.
- The rate at which glaciers have retreated over the past two decades has increased dramatically.
- Furthermore, despite Greenland’s wide variety of climate zones and glacier characteristics, scientists are finding that this latest acceleration of retreat is ubiquitous and includes Earth’s northernmost glaciers.
- Together, these findings indicate that the pace of retreat in the 21st century is exceptional for Greenland when viewed in the context of a century.
- The research was conducted by a group of researchers from the University of Copenhagen and GEUS together with American colleagues.
- The research has been published in the scientific journal Nature Climate Change.
Sea level rise and lack of water
Although Anders Bjørk says there is no longer much reason to investigate whether or not glaciers are melting, the development still needs to be closely monitored. Over the past two decades, melting glaciers have contributed to about 21% of observed sea level rise.
“Of course we keep a close eye on developments. We are in a new era in which glaciers are generally retreating, with major consequences for sea levels that will rise at an increasingly rapid rate,” he says.
Paradoxically, the melting of Greenland’s glaciers will lead to a lack of water. Glaciers will reach a point where they become so small that meltwater rivers will shrink or disappear altogether. This means, among other things, that Greenland’s ecosystems will change and renewable energy will face unforeseen hurdles:
“Today there is already a very real problem in Greenland: the locations where hydroelectric power stations were built 15 to 20 years ago, based on the melting of smaller glaciers, are not getting enough water because the ice has disappeared and is not regenerating. ,” says the researcher.
As a researcher and private individual, what do you think of the degree of melting that your research entails?
“I think it’s quite disturbing. Because we are well aware of where this is going in the future. Temperatures will continue to rise and glaciers will melt faster than now,” says Anders Bjørk, adding:
“But our research also shows that glaciers are responding very quickly to climate change, which in itself is positive because it tells us that it is not too late to minimize warming. Everything we can do now to reduce CO2 emissions will result in slower sea level rise. in the future.”
source : www.miragenews.com