Final answer:
The sentence in question is an example of a 'comma splice' because it joins two independent clauses with just a comma.
Step-by-step explanation:
The term for a sentence like "Many people believe that they can't bring about change, therefore, they don't vote during elections." is a comma splice. This error occurs when two independent clauses are joined by only a comma without an appropriate conjunction or punctuation like a period or semicolon. To correct a comma splice, one could add a conjunction such as 'and' or 'so' after the comma, or replace the comma with a period to create two separate sentences.