There are multiple axes of environmental impact. Carbon dioxide is one. There are also deforestation, erosion, renewability of the resource itself, and more. Bamboo or hemp are much more suitable for hygienic tissue than trees. The closer to market they can be farmed and processed, the better. The cleaner energy used to process them, the better. Still, bamboo and hemp grow so much more fiber per land area in the same amount of time, and are less detrimental to harvest.
Much of the same is true for bamboo fabric (versus, say, cotton). However the process used (such as viscose vs lyocell) can be environmentally damaging (in the example of viscose, the amount of water and chemicals used).
We bought bamboo tissue for a few years, but have since switched to recycled paper tissue (like many of its store brand products, the HEB grocer here in Texas has a pretty high quality product)
> “As far as emissions go, the technology used to create hygiene tissue paper is far more important than the type of fiber it’s made from,” said Naycari Forfora, lead author of the study and Ph.D candidate in the NC State College of Natural Resources. “Because the Chinese power grid is so reliant on coal for power, emissions throughout the entire tissue supply chain are higher than what we saw with the wood-based option.”
This is a bit silly. Of course something manufactured and shipped across the world is going to have a bigger environmental impact than something produced locally.