Climate Change in the Arctic - The Changing Arctic Environment: The Arctic Messenger - page 250

Despite this trend, there is always variability and October 2011to August 2012saw smaller
warm temperature anomalies over the central Arctic and therefore did not conform to
the strong positive surface temperature anomalies experienced between 2003 and 2010.
However, as we will see shortly, Arctic warming has achieved such momentum that the
2011-2012 surface air temperatures appeared to have little impact on record sea and glacial
ice loss occurring over the summer of 2012.
WhattemperaturechangescanweexpectintheArcticinthefuture?Thecrudeanswer
is that we can expect warming of the Arctic to continue throughout the twenty-first cen-
tury. The extent of this warming depends on what actions (if any) governments may take
in the near future to reduce GHG emissions. In order to study these different possibilities,
the IPCC published a Special Report on Emissions Scenarios (SRES) in 2000. Each global
scenario describes a different combination of possible demographic, economic, social and
energy-use trajectories that could characterize humankind in the twenty-first century. 10 Six
different computer models were used to increase confidence in the resulting SRES scenari-
os that are grouped according to a storyline and associated families:

· The A1 storyline and family explore a future of very rapid economic growth, a

global population peaking in mid-century, followed by a decline and a rapid intro-
duction of new and more efficient technologies. There is a general global conver-
gence in levels of economic development and of per capita income. There are
three families within the A1 scenario. Each family describes different possible
paths of energy production and use: fossil intensive (A1FI), nonfossil energy
sources (A1T) or a balance across all sources (A1B).

· The A2 storyline and family explore a future with pronounced differences in re-

gional economic development, lower per capita economic growth and a continu-
ously growing global population.

· The B1 storyline and family portray a similar future as the A1 storyline but with

rapid changes towards less energy-dependent economies and the intensification of
clean and resource-efficient technologies and environmental sustainability.

·