Environmental Engineering Reference
In-Depth Information
FIGURE 4.16 Mean sea-ice thickness for (left) March and (right) September based on ensemble members
from six models under A1B emissions scenario. (a and b) Year when the September ice extent reached 4.6
million km
2
by these models and (c and d) year when the Arctic reached nearly sea-ice conditions (less
than 1.0 million km
2
) in September. Source: Wang and Overland, (2009: Figure 3).
by the end of the 21st century for a global warming of 2-4°C above late
20th century values or 3-5°C above pre-industrial values This linear rela-
tionship between sea-ice loss and global-averaged surface air temperature
has implications for sea-ice recovery. One set of simulations using the A1B
scenario suggests that Arctic sea ice may recover if GHG emissions were
reduced. This response is linear for the annual sea-ice extent but nonlinear
for September (Holland et al., 2006, 2010).
Predictions for Antarctic Sea Ice over the 21st Century
Compared to the Arctic very few studies examine the predicted sea-ice
changes for the Antarctic. However, many of the characteristics of projected
change are like those for the Arctic. Over the 21st century Antarctic sea-ice
