If you're concerned about making as little negative impact on the planet as possible then why not buy a used kit from somewhere that's as close to you as possible?
Agree with this 100%. Recycling that doesn't involve reprocessing is by far the best method of reducing your purchase environmental impact, but of course, you can't control the upstream affect.
The metal hardware production component of drum manufacture, especially casted parts, has by far the biggest material processing impact, & almost every western drum manufacturer sources in Asia. Shipping is another big one, so add the two together, & the impact is exponentially increased. It could even be argued that Asian drum manufacturers reduce their impact in comparison to western manufacturers by sourcing all of their parts within the same continent. Then factor in the leveller that is distribution of the finished product, & everyone's got a problem.
Perhaps it's even more poignant to consider if it's unethical for Asian customers to buy from US/European companies, but I don't see anyone asking that question.
Also worthy of scrutiny are the statistics & trends themselves. Whilst it's true that China contributes to pollution much more than other countries, & their trend is going in the wrong direction, when you factor in the population that pollution "supports", the figures look quite different. I'd argue that's a more representative picture (see graph below).
The bottom line is this, for the most part (& I know I'll get flamed for this, but I'll say it anyhow), drummers are cheap. Like many other consumer groups, we look to the bottom Dollar. We examine "price" with utmost scrutiny, yet regard "cost" as an afterthought. Cost v.s. overall benefit received is almost lost in the wirl wind of pseudo patriotic marketing. Western consumer demands, with the expectation of ever reducing prices, forces even local manufacturing to outsource their higher cost components, rendering the reality of your patriotic purchase as anything but. If tomorrow, your home market manufacturers reverted to local sourcing, & chose processing methods that not only put quality first, but also lowered direct environmental impact, the resulting price hike complaint "threadfest" would consume this forum.
That drive to ever lower costs also places extreme pressure on outsource destination countries. Such governments are scared to do anything that may increase costs, & therefore decrease their attractiveness as a sourcing destination, no matter how well intentioned they may be personally or collectively. For the main part, it's western "manufacturers" who feed this cycle, by placing their business with the next guy who's prepared to throw more shit in the air than the last guy, & pay the lowest wages into the equation. Why do you think the outsource destinations are cyclical? In the 70's it was Japan, then wider to Taiwan, etc, then China, & probably India next.