No serious environmentalist I've read believes that misconception. In my view, that's another form of denial. Not the organized PR-flack fraud in the style originated by the tobacco industry, but just the normal human kind of wanting to ignore anything personally inconvenient.

I absolutely do not want to put off anyone from environmental work or a global call to change and stop of pollution and other unsustainable activities. But the fact remains that enough damage has been done that the consequences will be felt for a century, even if we turn around this ship tomorrow.

Sure. Today we're dealing with the environmental consequences of decisions made a century ago. E.g., water policy, urban planning, transport policy, effects of industry. Nature of the beast, really.