Everyone’s favorite topic is back in the news today. Climate change. There’s a new study out pointing the finger at who is most responsible for the recent rapid melting of the world’s glaciers. Yep, it’s us. A new study finds more than two-thirds of the recent rapid melting of glaciers can be blamed on humans.
Studying glacier melt has been going on for years. The most drastic changes appear to come from about 1991 on. “Glaciers are really shrinking rapidly now,” said climate scientist Ben Marzeion according to the AP.
“I think it’s fair to say most of it is man-made.”
Marzeion says about 69% of the glacier melt is man-made.
Since the 19th century, we attribute about 25% to glacial melt. But, if you look at the data from 1991 to 2010, that number explodes to 69% according to the study.
The main culprits of global warming are the usual. Burning of coal, oil and gas. Not to mention the explosion in global population over the past hundred years.
This study, published in Science, is the first to calculate exactly how much of glacial melting is attributed to us. According to the study, 295 billion tons of ice is melting each year due to human causes. About 130 billion tons is nature doing its thing.
Marzeion, along with his colleagues, ran several computer simulations on how much glacial melting there is from all causes. Then, they ran simulations factoring in just natural causes. The difference between the two makes up the portion we are responsible for.
Natural causes that began the glacial melting after the end of the Little Ice Age in the 19th century continues to elude scientists. They are convinced about the human causes, though. Climate change (think burning of fossil fuels), changes in how land is used, etc.
It should be noted there is a wide margin of error in the study. Humans role in glacial melting could be as low as 45% or as high as 93% in the study. The number likely sits somewhere in the middle. That’s where the 69% comes from.
Richard Alley, a glacier expert with Pennsylvania State University, told the AP, “This study makes perfect sense.”
What does this mean for the future? Well, there is a lag between the increase in global temperatures and the actual melting. That means we will see additional melting according to Marzeion.
Image credit: Ian Joughin, Univ. of Washington