Final answer:
The sentence 'When talking about recycling, people don't seem to consider the recycling of clothes.' has been correctly punctuated by placing a comma after the subordinate clause 'When talking about recycling.'
Step-by-step explanation:
To edit the sentence and add a comma to separate the subordinate clause from the main clause, we should identify the subordinate clause first. In the sentence provided, 'When talking about recycling' is the subordinate clause, which provides additional information but cannot stand alone as a sentence. Therefore, the correct placement of the comma would be after this clause. The edited sentence with the comma should read: 'When talking about recycling, people don't seem to consider the recycling of clothes.'