Proxy data used to estimate global temperatures of the past suggest that:
A) the earth is warming at an unusual rate.
B) the earth is warming at a rate consistent with natural causes.
C) the earth is cooling at an unusual rate.
D) the earth is cooling at a rate consistent with natural causes.

Question

Quizplus · Accepted Answer

Proxy data, which include tree rings, ice cores, and sediment layers, indicate that the current rate of global warming is much faster than historical natural fluctuations, suggesting an unusual rate of warming.

Proxy Data Used to Estimate Global Temperatures of the Past