Almost complete nonsense. The beaches are full of trash despite the best efforts of Trash Heroes, made up of mainly expats with a few Thais, but mostly because of the lack of any coordinated clean up campaign from the local authority, land owners and TAT, plus there is a MAJOR sandfly problem on the beaches. They've been pushing this low carbon destination for 10 years now. It's a tiny island, 16 sq km, but mostly the "low carbon" campaigns are to do with milking grants from central government. They tried to set up a recycling plant. It lasted a year or two, then it was back to burying/burning everything. There used to be a couple of places you could take your plastic bottles, run by locals, who shipped them all to the mainland. That system worked well. But there's only one left and his place is a junkyard. Some resort owners simply dump all their waste on land they've acquired especially for that purpose. In one instance, it's the first thing you see on arrival. When challenged, the answer is the usual "it's my land, I can do what I want with it".
There are successful initiatives though. Trash Heroes for one, which runs on most Thai islands, on a voluntary basis. No funding apart from enlightened locals. There's a coral planting enterprise run entirely by locals which I believe had had a lot of success. There's even a solar powered boat and some solar powered street lighting. Electricity used to be generated on the island but now comes via a cable from the mainland via Koh Kood.
Koh Mak used to be a back packers' paradise. But like most places in Thailand has overwhelming ambitions to move upmarket. The fact is, there's very little there and parents with children have a nightmare keeping their kids off the beaches for fear of them being bitten to death by sandflies.
Just my 2 satang worth.