Bill Tomlinson et. al find that an AI (ChatGPT, BLOOM,DALL-E2, Midjourney) writing a page of text emits 130 to 1500 times less CO2e than a human doing so. Similarly, an AI creating an image emits 310 to 2900 times less.

The figure shown below compares the CO2e emissions of AI and humans engaged in the task of creating one image. AI produces many times less CO2e than computer usage to support humans in making images.

Reference:

The Carbon Emissions of Writing and Illustrating Are Lower for AI than for Humans by B Tomlinson