When Mary Ann San Jose moved to Bulacan, northwest of the Philippine capital Manila, more than two decades ago, she could walk to the local chapel. Today, she would have to swim there. Land in her town and neighbouring areas has sunk between four and six centimetres (1.5-2.4 inches) each year since 2003. In recent decades, the rising waters have forced at least 5,000 people to abandon homes in the rural coastal areas north of the capital Manila. The fate of these towns also foreshadows what…