In recent years, the polar region has gradually changed, and turned from carbon sink to carbon source. In the past, the polar region was cold, the ice and snow were vast, and although the vegetation was thin, there was a lot of carbon in the ground. Its low temperature environment slows down the decomposition of organic matter, so more carbon is stored in it, making it a major carbon sink in the world.

At present, the global climate is changing, especially in the polar region. The temperature is gradually rising, the ice and snow are melting, and the frozen soil is also loose. When ice disappears, water travels its way, changing the landscape and hydrology. Permafrost releases carbon, and microorganisms increase their activity due to temperature changes, which speeds up the decomposition of organic matter, causing carbon to escape from the atmosphere in the form of carbon dioxide.

In addition, sea ice is decreasing, the sea area is open, and the habitat of marine organisms is changing. The rules of plankton reproduction are different from before, and its carbon fixation and cycle are also changed. And the growth season of polar plants is prolonged. Although green plants are slightly lush, the carbon emitted by respiration and soil microbial activities exceeds the amount of carbon sequestered by photosynthesis.

The polar region turns to carbon source, which has a profound impact on the global carbon cycle. Carbon entering the atmosphere increases the amount of greenhouse gases and promotes climate warming, forming a vicious cycle. Its changes also disturb the ecological balance, which is related to the survival of species and the rectification of the food chain. Therefore, it is urgent to gather all efforts to study and measure the changes in the polar region, and find countermeasures to slow down its carbon source trend and maintain the stability of the global climate and ecology.