Arctic sea ice disappears in summer by 2050
Already 2007 lowest on record by 22%
Abrupt Transitions in Summer
Sea Ice


¥Gradual
forcing results in abrupt Sept ice decrease
¥Extent decreases from 80 to 20% coverage
in 10 years.
¥Relevant factors:
¥Ice thinning
¥Arctic heat transport
¥Albedo feedback
Trenberth from Holland et al.,
GRL, 2006
2007 x