Positive and
Negative Feedbacks
Assume that the
Earth is warming.
¥Warming leads to
more melting of ice
¥Less ice reduces
EarthÕs albedo
¥Earth absorbs
more sunlight
¥Earth becomes
warmer melting more ice
Works in the
other direction as well:
Cooling makes more ice which reflects
sunlight which makes Earth
colder which makes more ice
=>ÕPositiveÕ Feedback Mechanism