Gardening

Which seems like a silly method of comparing emissions, given that the human doesn't exist for the purpose of creating images. The carbon footprint of the human is still present whether or not they are generating art.

Whether it's creating art with AI or via another means the human must be involved or else the art doesn't get created. They are a intrinsic part of the process and so their footprint must be included.

For an AI, the emissions are an addition to global carbon footprint

For Digital art (I.e Photoshop etc) the computer use is in addition to global carbon footprint. In Photography the construction of a camera is in addition to global carbon footprint. The list goes on. Either we either include the carbon footprint of all the tool(s) involved in the creation of the piece or we don't include any.

For the final point, a random social media post isn't a profit seeing endeavor, which is why it isn't expected to pay for any images it uses. The normal accepted practice is to just give credit to the source. The same is not true for news articles, which does care about there being a watermark and is expected to pay for image use. Unless of course people start accepting the normal use of ai images in which case disrupts a whole industry to provide worse art.

Whether it's 'accepted practice' or not is irrelevant. Using a watermarked image for anything without permission or license is illegal and fails to reimburse the artist that created it, the very thing you accuse AI of doing.