Anyone who takes on additional costs will be punished for it, because the hive mind of society always (read: _always_) (let me reiterate: always) favors lowest cost, all else being equal.
If your SaaS costs $12/mo because you voluntarily pay for offsetting all emissions that result, you are going to be hard pressed to beat the guy who doesn't give a fuck about emissions and offers an equal product for $10/mo.
The only way is to regulate these things to force compliance between all competitors. Emissions have a real cost, but it is far enough in the future to hide it. The government needs to force that cost into the present.
