I'd rather have reasonable numbers, and a good cost-benefit analysis. So it's nice to read an article that doesn't use the "Mother Nature" card, and instead attempts to give an argument based on numbers and fairness. One paragraph that I really liked has this to say about the issue:
"As for the argument that minerals are meant to serve humanity and are the raw materials for the modern conveniences we use everyday, the point is that, in cases where mining is allowed, the minerals should be priced at full cost, including environmental, social and economic costs. Otherwise, our poor who mainly bear these costs would be subsidizing the consumerism of the rich, both domestic and foreign."
Whether the numbers are right or not is something that does need investigation. But whatever the numbers are, an appeal for fairness is always a good argument.