If Walnut Creek paid an extra $9000/year for each resident then they could easily offset whatever extra environmental cost. Carbon offsets etc are not all that expensive.
2. Bart and muni are not the majority of the $9000 difference. The majority of the cost is various social services. The actual cost of muni per sf resident is something like $500, which is still significant (muni is not a great rapid transit system), but that's far less than the cost of carbon offsets for every resident.
2. Bart and muni are not the majority of the $9000 difference. The majority of the cost is various social services. The actual cost of muni per sf resident is something like $500, which is still significant (muni is not a great rapid transit system), but that's far less than the cost of carbon offsets for every resident.