Why Is Any Effort to Control the Greenhouse Effect So

Multiple Choice

Why is any effort to control the greenhouse effect so difficult?

A) The global economy depends on fossil fuels.
B) The greenhouse effect is a natural phenomenon necessary to keep the average temperature on Earth above freezing.
C) The global climate models are not yet dependable enough to determine energy policy.
D) There is no reliable substitute energy source available to the average citizen to replace fossil fuels on a global scale.
E) All of these are related to the complexity of this issue.