Continued from previous page
A policy is assumed to be optimal if marginal abatement costs are
equalized across countries, thereby minimizing total costs.
An opportunity is a situation or circumstance to decrease the gap between
the market potential of any technology or practice
and the economic potential, socio-economic potential, or
Opportunity cost is the cost of an economic activity forgone by the choice
of another activity.
Ozone, the triatomic form of oxygen (O3), is a gaseous atmospheric
constituent. In the troposphere it is created both naturally and by photochemical
reactions involving gases resulting from human activities (smog).
Tropospheric ozone acts as a greenhouse gas. In the stratosphere
it is created by the interaction between solar ultraviolet radiation and molecular
oxygen (O2). Stratospheric ozone plays a decisive role in the stratospheric
radiative balance. Its concentration is highest in the ozone layer.
Continues on next page