The most evident impact observed to date is a loss of ice due to warmer air and ocean waters. Warmer air causes the ice to melt more quickly and flow more rapidly to the sea, especially in low-elevation regions near the edges of the ice sheets.
Icebergs form when pieces of ice break free, or calve, from glaciers, ice sheets and ice caps. As global warming increases temperatures, more icebergs are calving from melting ice caps. Global warming is causing more icebergs to form, and these icebergs are melting at a faster rate than icebergs melted in the past.
The Arctic region is hauntingly beautiful. It’s a vast expanse of sea ice floating on water. Sea ice is actually frozen ocean water. It forms, grows, and melts in the ocean.
Arctic sea ice plays a major role in the Earth's global systems. It keeps the polar regions cool, influences climate, and provides a habitat for many animals.
But the amount of sea ice in the Arctic has been on a steady decline over the past two decades. In fact, the annual minimum area of sea ice is nearly 50% smaller now than it was in 1979.
So why is the sea ice shrinking? Arctic sea ice is melting at an alarming rate because ocean and air temperatures are getting warmer. Here’s how:
The burning of fossil fuels emits carbon dioxide and other heat-trapping gases into the atmosphere. The heat absorbed by these gases is radiated back towards the Earth’s surface. Then, the ocean absorbs this heat from the air. As the ocean heats up, sea ice melts.
The more the ice melts, the more ocean surface is exposed to the sun’s rays. Unlike sea ice that reflects the sunlight back into the atmosphere, the dark surface will absorb it, warming the region further. The cycle of warmer temperatures and ice melt continues.
In fact, air and ocean temperatures are rising faster than at any other time in history. If we are to understand how much and how fast the ice is melting, we need to be able to accurately measure it.
