Arctic regions are in the Northern Hemisphere, and it contains land and the islands that surrounds it.
Antarctica is in the Southern Hemisphere and it also contains the land mass, surrounding islands and the ocean.
The polar circles are imaginary lines shown on maps to be the areas that receives less sunlight due to less radiation.
These areas either receive sunlight (midnight sun) or shade (polar night) 24 hours a day because of the earth's tilt.
Plants and animals in the polar regions are able to withstand living in harsh weather conditions but are facing environmental threats that limit their survival.
[1][2] Much of the radiation from the Sun that is received is reflected off the snow making the polar regions cold.
The polar regions reflect 89-90% of the Sun radiation that the Earth receives.
Because of this the UV radiation that gets to the atmosphere can cause fast sun tanning and snow blindness.
Polar regions are dry areas; there is very little precipitation due to the cold air.
There are some times when the humidity may be high but the water vapor present in the air may be low.
[7] The ice melts along the coast during the summer months which are around June, July and August and the temperature may rise a few degrees above freezing causing there to be some vegetation.
Many of the ponds or lakes in polar regions are frozen over or snow-covered for most of the year.
In the summer the top of the permafrost may be covered with water due to melting in the area.
In warmer areas of the polar regions moths, butterflies and beetles can be found.
Some of the larger animals that exist are foxes, wolves, rabbits, hares, polar bears, reindeer/caribou.
Eight species of birds reside on the polar tundra year round while 150 breed in the Arctic.
The Arctic tundra vegetation also consists of lichens and mosses, but it includes shrubs, grasses and forbs as well.
The amount of vegetation in the tundra consists on how much sun, or snow cover is in the area.
The algae and lichens grow where there is moisture, and they hide in cracks to be protected from the wind.
In the Bering Sea there is a lot of fishing due to the high populations of halibut and Alaskan Pollock.
The cause of the depletion of the ozone layer is due to chlorofluorocarbons and other greenhouse gases.
There are many environmental effects due to this because of the gases that are being released five times faster than they are destroyed.
In Plan B 2.0 Lester R. Brown talks about how the Arctic is warming twice as fast as the rest of the world.
If there was a 1 m (3 ft 3 in) increase in sea level then millions of people would have to migrate from the coast.
[35] For animals, there has been a decrease in the number of polar bears in the Hudson Bay area.
This is because global warming causes the ice to break up faster so the polar bears are going to the coasts when there are poor conditions.
These nations include: Canada, Russia, Finland, USA, Denmark, Iceland and Norway.
There have been rules set up allowing only a certain amount of mining to be done and other measures to protect the environment from damages.
The Antarctic Treaty System of 1961 was established to make sure all the conflicts were resolved about who owned the land.
These laws manage the amount of hunting in the area, monitor invasive species, and control burning and settlement.