Glaciers & Ice Sheets

Why are they important?

Glaciers, particularly those located in high mountain ranges, provide essential freshwater to downstream populations, and the rivers they feed also power hydroelectric dams. Ice sheets store the vast majority of freshwater on the planet, but climate change is altering both snowfall patterns and the rate of melting, leading to overall losses of ice across the globe.

As ice melts and flows into the oceans, it raises sea level. As of 2014, sea level had risen 6.6 centimeters (2.6 inches) above 1993 levels, and continues to this day. This poses a problem for the hundreds of millions of people who live within five meters of the high tide line (approximately 10 percent of the global population). Unusually high tides and storm surges flood coastal communities much more frequently than they did 50 years ago, and as meltwater from ice sheets continues to contribute to sea level rise, these issues will only become more serious in coming years.

The Gulf Stream current, which brings warm water from the Caribbean across the Northern Atlantic to Iceland and Europe, is affected by the salinity of water. As meltwater from Greenland increases, it contributes large amounts of freshwater to the ocean’s surface. This could suppress the current, slowing the flow of water. The Gulf Stream exerts a strong influence on weather in Europe, and changes in ocean circulation would have large impact on the transfer of heat across the globe and resulting weather patterns.

How are scientists studying glaciers and ice sheets?

Researchers are monitoring glaciers and ice sheets in an effort to track changes in their structure and predict future losses of ice and the resulting impact it will have on sea level. Tracking something as massive as an ice sheet isn’t an easy task. Researchers can compare the outflow of water with snowfall accumulation to understand whether the ice is stable, growing, or declining. Or they can use satellites to estimate the total volume of ice, rate of movement, amount of melting, and overall changes in ice loss. As a result of these efforts, scientists have found that Greenland and Antarctica are losing as much as 120 gigatons of ice each year, and that rate is increasing over time.

Scientists also take ice cores to study Earth’s past climate. When snow falls and metamorphoses into ice, it traps tiny pockets of air that provide a glimpse of historical atmospheric conditions. Particulates in the ice can reveal volcanic eruptions, dust storms, and other events. As ice continues to melt at a faster pace, scientists are working quickly to obtain cores for future study before the source ice is gone.