Context: Recently, a team of scientists has come up with a bizarre plan to fill the Arctic with hordes of Grazing animals like reindeer and bison. The idea is to keep the permafrost frozen by trampling it under the weight of these hordes. Climate change and its harmful impact on the Arctic is not unknown. However, the idea of fighting climate change or global warming with hordes of grazing animals is something unheard of before.

Key Points

• As per the team of scientists, this trick alone could save 80 percent of the Arctic’s permafrost until the year 2100. The sounding reason behind this lies in the equation between the snow and the soil.
• In the Arctic, the snow that falls on the ground starts acting as a layer of insulation between the soil and the frigid air above it.
• The idea is that restoring large herds of animals to the Arctic landscape could help protect permafrost, a carbon-rich layer of permanently frozen soil stretching across much of the tundra.
• As temperatures rise in the rapidly warming Arctic, large swaths of permafrost are beginning to heat up and melt, releasing climate-warming carbon emissions in the process.
• Due to worsening climate change, that insulation results in the soil’s temperature to rise. Beyond a point, this temperature rise eventually results in the permafrost beginning to thaw.
• The study mentions that large herbivores like bisons and reindeers disperse the snow insulation as they walk around. In addition, these animals also help stamp down and compact the soil beneath them.
• There are, however, still doubts on the feasibility of the study. A simple question that renders it impractical is the scale at which it would have to be applied to attain any significant results.
• The increasing climate change is headed towards tipping the Earth to a point of no return. The impact can be seen at almost every point on the planet.
• The arctic, for instance, was recently found with a 1 million square kilometre wide hole in the Ozone layer. Usually, such occurrences were limited to the South Pole.

About Permafrost

• ‘Permafrost’ or permanently frozen ground is land that has been frozen at or below 0 degrees Celsius for two or more consecutive years.
• A staggering 17 per cent of Earth’s entire exposed land surface is comprised of permafrost.
• Composed of rock, sediments, dead plant and animal matter, soil, and varying degrees of ice, permafrost is mainly found near the poles, covering parts of Greenland, Alaska, Northern Canada, Siberia and Scandinavia.
• The Arctic region is a vast ocean, covered by thick ice on the surface (called sea ice), surrounded by land masses that are also covered with snow and ice.

About Permafrost thawing

• When permafrost thaws, water from the melted ice makes its way to the caves along with ground sediments, and deposits on the rocks.
• In other words, when permafrost thaws, the rocks grow and when permafrost is stable and frozen, they do not grow.

Reasons behind thawing
The link between the Siberian permafrost and Arctic sea ice can be explained by two factors:

• One is heat transport from the open Arctic Ocean into Siberia, making the Siberian climate warmer.
• The second is moisture transport from open seawater into Siberia, leading to thicker snow cover that insulates the ground from cold winter air, contributing to its warming.
• This is drastically different from the situation just a couple of decades ago when the sea ice acted as a protective layer, maintaining cold temperatures in the region and shielding the permafrost from the moisture from the ocean.
• If sea ice (in the summer) is gone, permafrost start thawing.