Chemical change because a chemical change is any change that results in the formation of new chemical substances.
The sequential events in the Arctic ecosystem feedback loop are: Global temperature increases → permafrost thickness decreases → methane increases → global temperature increases. It is harmful to the Earth.
The Arctic ecosystem is a feedback loop because the warmer the temperatures, the less sea ice (permafrost) is observed.
The Arctic ecosystem feedback loop is a dangerous phenomenon because it accelerates global warming.
Permafrost refers to ice ground that remains completely frozen (0°C) for at least two (2) or more years straight.
Learn more about the Arctic ecosystem here:
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I believe it is idiopathic.
The pneumatic bones are important to birds for respiration. They are hollow bones which are connected to the bird's respiratory system and are important for birds to be able to breath. Examples of pneumatic bones are the skull, humerus, clavicle, keel (sternum), pelvic girdle, and the lumbar and sacral vertebrae.
