Bay Citizen: These two buildings could be getting some brothers and sisters soon. A new plan would allow for three more 180-foot tall high-rises in downtown Berkeley. Most people would assume that environmentalists would rather protect tall trees than tall buildings. But, increasingly, even the staunchest environmentalists are advocating plans to build up cities near transit hubs in order to curb sprawl and limit emissions of greenhouse gases. That has created a split in the environmental movement. Nowhere…