Why is it important to recognize and include uncertainties when ...

[mydiamond]

Why is it important to recognize and include uncertainties when dealing with data? Use uncertainties described and graphed in this chapter, and others, as examples in your answer.
 
  What will be an ideal response?

Question 2

How do volcanic eruptions affect Earth's temperature?
 
  What will be an ideal response?

[prumorgan]

Answer to Question 1

Very few measurements are known with absolute certainty. Measuring devices may provide values only within certain bounding possibilities. Repeated measurements sometimes differ slightly, showing uncertainty in the measurement method or measurement device. When averaging data together representing intervals of time or regions of Earth, the average values may not represent all of the actual variability. When drawing conclusions from data, it is important to consider whether differences are larger or smaller than the uncertainty in the data itself. If differences are less than the uncertainty, then the differences may not be real or meaningful. For example, in Figure 21.16, if you look at the black temperature line, you could conclude that global temperature in 1950 (the right end of the line) was greater than at any time between 100 and 1950. However, by looking at the uncertainty in the proxy temperature values, it is difficult to justify that conclusion.

Answer to Question 2

Explosive volcanic eruptions eject large volumes of volcanic ash and sulfurous aerosols into the atmosphere, both of which block or absorb incoming solar radiation to cause cooling. The aerosol effect is the greater one because the aerosols can be distributed throughout the atmosphere and remain there for many years; most of the ash particles settle out within days or weeks and are only present in areas downwind of the volcano.