That pollution harms the environment is self-evident; that immediate government action to combat it is merited by the situation is a matter of debate.
A. that immediate government action to combat it is merited by the situation
B. if the situation merits immediate action by the government is a matter of debate
C. whether to combat the situation is merited by immediate government action
D. that the situation merits immediate government action to combat it
E. whether the government should immediately combat it is merited by the situation
I seem to be weak at semicolon questions. Explanations will be appreciated.
That X.... ; that Y ....
The semicolon just links two main ideas (pollution), or rather clauses, that can stand asindependednt sentences. Probably written somewhere in your 800 OE. "it" doesn't need a clear antecendent here because the semicolon indicates continuation based on the same subject.