How should I read claims about wealth and environmental damage?

First check what “environmental costs” means here. Is the estimate about emissions, damage to health and ecosystems, or a bundle of impacts? Then look for the time period, the data used, and how costs were assigned to people. A figure in dollars can sound precise while depending heavily on choices about what to count and how to value it.

There’s also a difference between attributing impacts to someone’s direct consumption and attributing them through investments or business ownership. Those methods answer different questions, and combining them without care could count some impacts twice.

I’d be wary of treating a group label as an explanation by itself. People within the same income bracket can have very different consumption and financial ties, while some major impacts may be linked to companies or systems rather than one person’s choices. A useful analysis should say what responsibility it is measuring, instead of sliding between personal behavior, ownership, and political influence.

That doesn’t make the question pointless. It means a strong version of the claim should show its workings and make clear what the estimate can, and can’t, support.