AUSTIN (KXAN) — New research from the University of Texas has revealed humans are likely responsible for rapidly melting glaciers. The study, published July 13 in the journal “The Cryosphere,” used computer models to test how global warming impacted glaciers.
They found even “modest” warming cased glacier melt to accelerate.
“When you get this many glaciers retreating simultaneously, there’s no way to explain that outside of an external climate change happening,” said Ginny Catania, a glaciologist and professor with the University of Texas.
The study was done by researchers from the University of Texas Institute for Geophysics and Georgia Tech. The team, led by Catania, said its research could help predict when major ice loss would occur and the impact it could have on Earth’s oceans and climate.
What makes this research different is it treated glacier melting or retreating as a single event, much like “a wildfire or tropical storm.” As glaciers melt, they retreat back to their source. Where there was ice, there’s now more water.
How did these models prove climate change was causing glacial retreat?
“We know there are natural fluctuations in the ocean temperature that also affects these glaciers. And these are, for the most part random,” said John Christian, a postdoctoral researcher who worked on the project. Christian developed the computer model the team used.
Thousands of simulations were run using data from the past 150 years. The team factored in global warming trends and then factored them out. Each time warming was factored in, glacier retreat became more probable.
“We think we have now a better way to look for the human influence on these glaciers going forward,” Christian said.
When the team didn’t factor in climate change, only a few of the glaciers retreated. Since 2000, 200 of Greenland’s 225 glaciers have been in retreat.
What causes a glacier to melt faster?
Beneath a glacier, there is rock. This rock protects the bottom of the glacier from warm ocean water that could get beneath it. If this water gets under the glacier, it then begins to melt from beneath. This is what causes the glacier to crack, break apart and fall into the ocean.
According to the scientists, for a large retreat to occur, the glacier must melt past a stability peak. This peak is hard bedrock that becomes a point and prevents more water from getting beneath the glacier.
Once the glaciers retreat past this stability peak, it will melt rapidly. The animation below shows this rapid melting.
The computer models the team ran take this stabilizing peak into account. It also allows scientist to study each glacier individually and factor in the climate around the glacier and things like global warming.
“We can see how glaciers retreat very rapidly off of these bumps in in the last like, 30, 40 years of satellite data,” Catania said.
Currently, the model uses generic glacier data. “The next step is to apply it to specific glaciers and, and see how much climate change has affected each of those,” Christian said.
Get ready for ‘The Day After Tomorrow’
So why should you care about glaciers in Greenland melting? Remember the Jake Gyllenhaal/Dennis Quaid masterpiece “The Day After Tomorrow”? That’s why.
According to researchers from the University of Southampton, melting glaciers could cause changes to the Atlantic Meridional Overturning Circulation (AMOC). This circulation is a system of ocean currents that brings warm and cold water from the Gulf Coast to Europe.
Glaciers melting add cold water to this warm water system and cause the circulation to become denser. This could cause the AMOC to shut down. A report by the Intergovernmental Panel on Climate Change (IPCC) found the AMOC will likely weaken in the coming decades.
Continued melting of glaciers could cause the AMOC to shut down, although the IPCC found this unlikely to occur by 2100.
If the AMOC were to collapse, scientists said temperatures in Europe and in eastern North America could drop by nine degrees Fahrenheit. There likely be more extreme winter, while Texas will see drier and hotter weather.
Another major concern, sea level rise. The US Geological Survey says that if all the glaciers on Earth melted, sea level would rise by 230 feet.
We’re going to have to deal with sea level at the Texas Gulf Coast, in particular, we’re going to have to deal with more extreme summers,” Catania said. This means cities like Houston, Galveston and Corpus Christi will be underwater.