In the summer of 2019, 800 million tons of snow and ice disappeared from Swiss glaciers during two weeks of summer. Global warming is causing glaciers in Switzerland and the Alps to disappear rapidly. At this rate, all 1,500 Alpine glaciers may disappear within 30 years. Japanese weather satellites have also revealed that Greenland, which is covered in ice all year round, is beginning to melt in the summer.

The Arctic is also greatly affected by global warming. The average temperature in the Arctic is rising twice as fast each year as the rest of the world. The Arctic, unlike Antarctica, does not sit atop land and is mostly made up of ice floating in the ocean. While Antarctic ice is thousands of meters thick, Arctic Sea ice is only a few meters thick. As the average temperature in the Arctic has increased, the sea ice has continued to melt and shrink. The Arctic ice pack has decreased by 1 million square kilometers in the past 30 years. If this trend continues, it is estimated that it will decrease by more than 50% by 2050.
Polar bears are the animals most affected by this environmental change. It is normal for polar bears to go without food during the summer months when the ice melts. However, the longer the ice melts last, the weaker they become and the less able they are to reproduce. Arctic seals, which are the primary food source for polar bears, are also unable to raise their young because their nests in the snow are being destroyed by global warming.

Global warming in the Arctic also affects the entire planet. Sea ice is originally frozen ocean water, so even if it melts, sea level will not rise. But when ice and snow on land in the Arctic, such as in Greenland and Alaska, melt and flow into the ocean it causes the sea level to rise. This affects the entire planet. Another major problem is the melting of permafrost and the release of methane gas. Methane gas is a greenhouse gas that causes global warming along with carbon dioxide. Moreover, its greenhouse effect is about 21 times stronger than that of carbon dioxide. Methane gas that has been trapped in the ground is now being released due to global warming, and this is accelerating global warming in the Arctic region.

episode 5
The Planet’s Glaciers and Ice Sheets are Melting

Detailed Data and Explanation 1:
Greenland Ice Sheet Melting.

Greenland is a large island between the North Atlantic Ocean and the Arctic Ocean, mostly within the Arctic Circle, and most of the island is covered with ice all year round.
JAXA's SHIZUKU satellite, which was launched in 2012 to observe changes in the water cycle, soon discovered that the surface of the Greenland ice sheet was wet over almost the entire area. In other words, it found that the ice was melting. Greenland's surface is usually frozen solid even in summer, and JAXA had previously observed this area with other equipment, but it was the first time to see such a change. This is further evidence that the effects of global warming are reaching the Arctic Circle.

Courtesy of JAXA (Japan Aerospace Exploration Agency)

Detailed Data and Explanation 2:
Sea ice in the Northern Hemisphere is rapidly decreasing.

Source: National Center for Climate Change Actions website （ https://www.jccca.org ）より

The graph above shows projected changes for sea ice in the Northern Hemisphere. There are two projections: blue and red. The blue graph shows the scenario where maximum global warming prevention measures have been implemented to keep the future temperature increase below 2°C. While the red graph shows the scenario where no global warming prevention measures are taken.
Even with the least warming scenario in blue, sea ice coverage is projected to be 43% smaller by the end of the 21st century than it is today. On the other hand, in the red, the most advanced warming scenario, sea ice in the Arctic region is likely to disappear by the middle of the 21st century.

Below is a projection of the Arctic Ocean at the end of the 21st century. In the red scenario (above), no sea ice is visible. In the blue scenario (bottom figure), the Arctic ice pack is predicted to be significantly smaller than it is today.

Source: National Center for Climate Change Actions website （ https://www.jccca.org/ ）より