Context: The recent IPCC report has warned that increasing global warming will result in reductions in Arctic permafrost. This will result in releasing of greenhouse gases like methane and carbon dioxide.
What is Permafrost?

• Permafrost is any ground that remains completely frozen—32 °F (0 °C) or colder—for at least two years straight. 
• Permafrost covers about 15% of the land area of the globe. They are most common in regions with high mountains and in Earth’s higher latitudes—near the North and South Poles.

What is Permafrost made of?

• Permafrost is made of a combination of soil, rocks and sand that are held together by ice. The soil and ice in permafrost stay frozen all year long.
• Near the surface, permafrost soils also contain large quantities of organic carbon—a material leftover from dead plants—that couldn’t decompose, or rot away, due to the cold. Lower permafrost layers contain soils made mostly of minerals.
• A layer of soil on top of permafrost does not stay frozen all year. This layer is called the active layer. This layer thaws during the warm summer months and freezes again in the fall. In colder regions, the ground rarely thaws—even in the summer. 

How Does Climate Change Affect Permafrost?

• As Earth’s climate warms, the permafrost is thawing. That means the ice inside the permafrost melts, leaving behind water and soil.

Thawing permafrost can have dramatic impacts on our planet and the things living on it. For example:

• Firstly, many northern villages are built on permafrost. When permafrost is frozen, it’s harder than concrete. However, thawing permafrost can destroy houses, roads and other infrastructure.
• Secondly, when permafrost is frozen, the plant material in the soil—called organic carbon—can’t decompose, or rot away. As permafrost thaws, microbes begin decomposing this material. This process releases greenhouse gases like carbon dioxide and methane into the atmosphere.
• Thirdly, when permafrost thaws, so do ancient bacteria and viruses in the ice and soil. These newly-unfrozen microbes could make humans and animals very sick. Scientists have discovered microbes more than 400,000 years old in thawed permafrost.

NASA’s Mission to monitor Permafrost

• NASA’s Soil Moisture Active Passive(SMAP): The mission orbits Earth, collecting information about moisture in the soil. It measures the amount of water in the top 2 inches (5 centimetres) of soil everywhere on Earth’s surface. It can also tell if the water within the soil is frozen or thawed.