When Omar El Akkad returned to the playground where he snuck his first kiss as a teenager in Doha, Qatar, he was dismayed to find the swings and slides replaced with skyscrapers and hotels. But the rapid urban transformation of one of the richest countries on Earth reminded him of another kind of obliteration, a loss driven by his former country’s unnervingly rapid warming and its overpowering role as oil magnate—a role that may one day influence the fragmentation of millions of migrants’ own disjointed memories.