Label the following as true, false, or uncertain, and explain your choice. (Uncertain means that it can be either true or false depending upon the circumstances.)

a. The imposition of a tax on currently uncontrolled greenhouse gas emissions would represent a move toward efficiency.

b. Relying on a series of regional systems (like the E.U. ETS), rather than a true global system, for controlling greenhouse gases increases the importance of the leakage problem.