It reduces it. Instead of taking a barrel of oil, moving it to a different place and burning 10% of it in the process, or even 20%, it can be easily be used right there use 20% less, and cheaper as well. No need for ships to be built, sailors to sail and so on. Less emissions, not zero but a reduction, and cheaper.

Just moving bits around seems like a lot easier, efficient and cheaper than moving physical stuff around.

Edit: bad calculation fix