Educate the buyers. The earth will survive us.
I think we should mandate that civilization be rolled back to back to the 1700’s when passenger pigeons darkened the air for days and the buffalo herds stretched as far as the eye could see and a squirrel could travel from the Mississippi to the East coast without touching the ground.
Seriously, educate the buyers. If it is indeed that serious of a problem, show them what they are doing.
As a conservative with a libertarian leaning, that's the solution I would prefer. In a constitutional law class once, I got into an argument with a very liberal teacher who said that the Supreme Court "had" to prohibit child labor in North Carolina because everybody in the country was against it and there was no other way to stop it.
My response was: "Umm. If everybody is against it, and they simply quit buying products made by kids in North Carolina, wouldn't that stop the problem?"
She was a big supporter of Caesar Chavez and his produce boycotts, but didn't understand how other boycotts could work.
In this case, I'm not certain it's that easy. In the guitar world, a lot of buyers won't touch a guitar made of Madagascar Rosewood for ethical reasons. Others are willing to pay the extra $2,000+ simply to have the base grade Madagascar Rosewood (or $4,000+ for better grade, and, no, I didn't make up those amounts) because (a) of how it looks, (b) of how it sounds, (c) it may be worth a lot of money someday because it's likely to become completely illegal to get, or (d) "I'm not hurting anything because the Madagascar rosewood has already been cut down".
In part, they're right. It's a chicken and the egg situation. If Americans stop buying Madagascar Rosewood, the armed bandits will still cut down trees in Madagascar. Somebody, somewhere, will buy it. Especially the Chinese. Americans will still buy musical instruments with it on the grounds that the wood's already been cut.
It's likely a losing battle, despite the fact that so many world-wide organizations have gotten involved in trying to stop illegal logging in Madagascar.