ESS101C
Prof. Jin-Yi Yu
What Caused the Twentieth-Century Warming?
qThe warming is a
result of human impacts
This explanation will be true if the warming of the twentieth
century has been unprecedented in magnitude over the last 1000 year or more of recent climate history.
qThe warming is part of the natural
variability
This explanation will be true if comparable warm intervals
occurred before or even during the Little
Ice Age.