Cotton grass, which grows only in arctic regions, has been the only summertime source of protein available to caribou  Caribou that do not get adequate amounts of protein in the summer are unable to reproduce the following year  Rising average temperatures in arctic regions, however, are causing cotton grass to disappear
Ttherefore, if the warming trend continues, caribou are likely to become extinct
The warming trend in arctic regions will not enable other plants capable of providing protein to caribou to grow there.