MEGAN ROWLING THE growing impacts of climate change have already pushed more than 18 million people to migrate within South Asian countries, but that could more than triple in three decades if global warming continues on its current path, researchers warned on Friday. Nearly 63 million people could be forced from their homes by 2050 in the region as rising seas and rivers swallow villages, and drought-hit land no longer supports crops, said ActionAid International and Climate Action Network South Asia in a report. The projection does not include those who will be forced to flee sudden disasters such as…