These replies feel combative and condescending, and I'm concerned that good points you make will be shrugged off by someone if you put them on the defensive with this style of writing. I want to be clear that I think your stance has merit, and while I agree with you in general context is important. I apologize for leaving it out of the description hoping for it to spur more conversations. This whole exchange could have been more enjoyable if it had started out like "How do you justify the ethics of their use given the considerable carbon footprint of their existence?" but part of that responsibility lies with me.

one time only?

No, we've set up relationships with several of the arborists and loggers that operate in the forestry district in which we live. Last year we received the equivalent of a tractor trailer load from another abutting property after it was harvested for firewood. The year before that we took almost three hundred yards of chips from the town during a municipal project. Our arborist friends know that we'd rather those chips be left with their customer, blown out responsibly, or dropped at a location closer to their job site than we are.

"I'm saving the chips" is a common excuse

In our area, the lifecycle of wood chips looks like this: Become chips, get hauled to a processing facility, undergo further grinding or tumbling to become "playground chips" or small enough to become wood pellets or fire bricks. Once at that stage, they'll be hauled further to be delivered as mulch or turned into heating products which are then packaged and shipped several more times. There are so many pain points along that system from the "stop burning fossil fuels" perspective that you and I share, and it feels correct to do what I can to reduce that consumption.

Mollison, Holmgren, Lawton, Holzer, and others have written about the idea that a use of fossil fuels to set up a productive permaculture system can be justified if that system reduces your other fuel uses. There's also an emphasis on diverting waste streams and closing those loops, and (tongue in cheek here) I value the marginal impact I have when I can keep the chips from racking up additional fuel consumption. From my perspective if the intentional use of fossil fuels for establishment is "okay", then establishment which reduces the footprint that would have existed without my involvement is at least an order of magnitude better.