Climate Change in the Arctic - The Changing Arctic Environment: The Arctic Messenger - page 253

An example of the use of the RCPs in an Arctic context is provided in Figure 10.6 ,
which shows historical, observed and projected temperature anomalies specifically for the
Arctic. Using the HadCRUT4.2 dataset, 11 it can be shown that Arctic land has warmed
by 1.5°C during the 1973-2012 period, while the globe (land and ocean) has warmed by
0.69°C. That is a factor of 2.2, which coincides well with observational data. This increases
our confidence in the projections for the future.
Figure 10.6
Observed and simulated variations in past and projected future annual average temperature over land
areas north of 60 0 N
I have mentioned several times already that the Arctic is warming faster than elsewhere.
Several factors are at play here that collectively contribute to this phenomenon, known as
Arctic amplification . The most dominant are associated with positive feedback resulting
from the progressive loss of ice and snow. A positive feedback is a process in which an
initial change will bring about an additional change in the same direction (leading to amp-
lification).