Proxy data:
A)provide climate data representing times when instruments were not available to measure them.
B)are difficult to find because they occur only in very limited areas.
C)come quality-controlled instrument records.
D)can only extend the temperature record back an additional 500 years.

Question

Quizplus · Accepted Answer

Proxy data provides climate data from times before instruments were invented or available to measure them.

Answer: B 
 Proxy data can be difficult to find as they occur only in limited areas such as ice cores, tree rings or sediment layers.

Answer: C 
 Proxy data are not quality-controlled instrument records as they are indirect measures of past climate.

Answer: D 
 Proxy data can extend the temperature record back further than 500 years in some cases, depending on the type of proxy used.

Proxy Data