How do I solve 3 across in Daily Telegraph Cryptic 31253?

Question

Accepted Answer

3 across reads "Marcel Marceau seemingly such a green activist?" (4-6 letters); the answer is TREE-HUGGER. It's a charade: the answer breaks into parts in clue order, each part clued by a word or short phrase. No indicators needed; watch for standard abbreviations (RA = artist, US = American, IN = at home) and short synonyms. The full step-by-step breakdown is on this page.

Marcel Marceau seemingly such a green activist? (4-6)

3A — Marcel Marceau seemingly such a green activist? (4-6) — TREE-HUGGER