The costs of mitigating carbon buildup in the atmosphere can potentially be very high, since it could require reductions in fossil-fuel burning.
(The costs of mitigating carbon buildup in the atmosphere; can potentially be; very high; since it could require reductions in fossil-fuel burning) (it; could require; reductions in fossil-fuel burning)
The costs of mitigating carbon buildup in the atmosphere it
can potentially be could require
very high since it could require reductions in fossil-fuel burning
reductions in fossil-fuel burning