If you want to know how things are going in our planet's permanent ice zone, the north coast of Alaska is a good place to start. It's not the view out to the horizon in the search for polar bears that provides answers, though. Rather, it is the ground under your feet. Permafrost.

Places like this are perfect for observing an alarming effect of global warming – one which experts say has received far too little attention for far too long.

The global permafrost inventory is estimated to store around 1,500 gigatons of carbon. If that permanently frozen soil thaws out, the organic material it contains – some of it up to 100,000 years old – will be broken down by microorganisms. And that process will not only release CO₂, but also methane and nitrous oxide. If those gases reach the atmosphere, the result could be a rise of 0.3 degrees in average global temperatures by the year 2100, scientists have warned.

Around 20 percent of the world's land area is covered by permafrost. From 2007 to 2016, researchers recorded permafrost temperatures at 123 stations across the globe and found significant increases at more than half of those stations. At five of the stations, the permafrost thawed completely during that time period.

Still, even though the fact that the permafrost is thawing out is not a matter of controversy, scientists do have competing views regarding how quickly this process is moving. And how much greenhouse gas will be released as a result.

Antarctica

Antarctica, home to the world's largest ice sheet, has likewise not escaped the effects of global warming. For quite some time, there was a widespread assumption that, because of the extremely low temperatures on the southernmost continent, the Antarctic ice sheet was not vulnerable to melting.

Furthermore, in contrast to the ice at the North Pole, the melting of which has accelerated dramatically in the last several years, the sea ice surrounding the continent of Antarctica has actually expanded in recent winters. Researchers, though, believe that winds, ocean currents and reduced salt content in the water is responsible for the phenomenon.

But when it comes to the ice on the continent of Antarctica itself, satellite-supported measurements are painting a completely different picture: The ice sheet, which is several kilometers thick, is increasingly losing mass.

Greenland

Most of Greenland's ice is also on land. According to current research, Greenland lost almost 5,000 gigatons of ice between 1972 and 2018, resulting in a global sea-level rise of 13.7 millimeters. According to figures from 2019, a million tons of Greenland ice is melting every minute.

The total amount of ice on Greenland is estimated to be 21.6 million gigatons, which would boost the sea level by around seven meters if it were all to melt. Because Greenland’s climate is relatively moderate compared to Antarctica, just a few degrees of warming would have extreme consequences.

A recent study claimed that Greenland has already reached a the "tipping point" – that the Greenland ice will melt completely in the coming centuries regardless of how significantly global CO₂ emissions are reduced. Other researchers, though, are skeptical of this forecast.

North Pole

The sea ice and shelf ice in the Arctic is also melting quickly. In the summer of 2020, the Arctic ice sheet receded to its second-lowest extent since satellite measurements began over 40 years ago. Current studies forecast that the Arctic Ocean could even be completely ice free in the summer by 2050.

The effect on sea levels, though, would be negligible. Floating ice produces roughly the same amount of water when it melts as it had previously displaced.

Mountain Glaciers

That is not the case, however, with the roughly 200,000 mountain glaciers around the world, the volume of which is also shrinking rapidly. A recent study reached the conclusion that the volume of ice in mountain glaciers will have shrunk by around a quarter by the year 2100, increasing sea levels by up to 16 centimeters.

Many experts are also concerned by the fact that the speed of melting is accelerating. One of the reasons is a phenomenon bearing the rather unwieldy name of "ice-albedo feedback effect."

Put simply, the albedo effect describes the difference between sitting in the sun wearing a white T-shirt or a black T-shirt: What percent of sunlight is reflected or absorbed?

Snow cover has a high albedo: It reflects around 90 percent of sunlight. That protects layers of ice below from the sun and the surrounding air warms very little.

Water and ground without an ice covering, by contrast, absorb between 80 and 90 percent of sunlight, which results in sharp temperature increases in both the land and the water, which in turn warms up the temperature in the surrounding area.

These higher temperatures lead to more melt water, which due to its own low albedo, absorbs even more energy from the sun. This self-reinforcing process is called "positive feedback."

The melting of the world's ice already has consequences for millions of people. From Europe to South America to Asia, glaciers provide water for drinking, agriculture and energy production.

The disappearance of ice and the stability it provides also increases the risk of landslides and avalanches.

The effects on tourism are also significant. For many regions, a sufficient quantity of snow in the winter is critical to economic survival.

In places like the Schneeferner Glacier on Germany's highest mountain, called the Zugspitze, one can see the often-futile efforts to limit the effects of climate change.

For 20 years, the company that operates the cogwheel rail line to the top of the mountain covered up to 6,000 square meters of the glacier with snow and then with white tarps.

The hope was to reduce melting during the summer months and to perhaps even grow the glacier due to the weight of the tarps. But the project was abandoned in 2013 due to a lack of any appreciable effect.

Since then, the remains of the once impressive glacier have continued to melt away each summer. Researchers believe it will have completely disappeared within two decades, if not sooner.

It is a fate awaiting numerous Alpine glaciers in the coming decades. The Intergovernmental Panel on Climate Change (IPCC) believes that they will lose an average of 80 percent of their mass by 2100.

And many of them won't be salvageable even if efforts to combat climate change are ramped up significantly, a recent IPCC report notes. But that also means that there is still some hope for them. To fulfill that hope, greenhouse gases in the atmosphere – the primary cause of global warming – must be dramatically reduced. Only then does our Earth stand a chance.