The point was that some things are irreversible, it is ~already~ unacceptable, and each step in that direction is a worse condition for that time.
I don't consider it a small pile with a shovel vs. large pile with a backhoe, it is a large pile already, and may become an insurmountable obstacle, or do more significant damage which cannot be fixed. Whether there are shovels, backhoes or an electromagnetic massdriver - I do not have confidence it will be used appropriately or in a timely fashion without continuing to support the causes which educate, research and lobby for changes now, even if it is a marginal change. Even disregarding that, any sort of tool of the future has to be built assuming progress today for such technologies and techniques. There are already ecosystems of enormous size and significance that are destroyed, which impact their own areas, the global ecosystem, not to mention the existence value of such systems, the species that can (or once could be) found in them and the impact upon humans by way of the food chain (outright supply of food, quality of life, contamination by chemicals) and appreciation for nature itself.
This is already happening, and it is already unacceptably bad. This isn't theory, this is the yellow bubble you see when you look down on Atlanta, the mercury in fish supplies and that you can pretty much walk across some major river systems without divine assistance, and I honestly don't give a damn if it could theoretically be fixed in some future, it is causing harm now, and I feel nearly compelled to do ~something.~

Suffice it to say, this post has provided minimal surprises.