Population displaced by sea level rise. Al Gore presentation to Senate Foreign Relations Committee SD 419 PARIS, Nov 29 (AFP) Nov 29, 2009 — The UN refugee agency says some 24 million people worldwide have fled their homes due to environmental factors, and warns their ranks could grow tenfold by mid-century, spurred greatly by climate change. Sheer numbers and the lack of legal status under international law mean a vicious humanitarian crisis is looming, say experts. Bottom line? Millions of hungry, poor, vulnerable people may simply have nowhere to go. “In the future, who is going to open their doors to all this misery?” is the rhetorical question asked by Jean-Francois Durieux, in charge of climate change at the UN High Commissioner for Refugees (UNHCR). … “Environmentally induced migration has the potential to become a phenomenon of unprecedented scale and scope,” said Koko Warner at the UN University Institute of Environment and Human Security in Bonn, Germany. “At 4.0 C (7.2 F), climate-driven migration redraws the map of population distribution across the surface of the globe,” said Francois Gemmene of France’s Institute for Sustainable Development and International Relations (IDDRI). At least three forces are likely to push people in search of more hospitable terrain: rising sea levels, drought and dying coral reefs. If the world’s population peaks at about nine billion in 2050, a large chunk of humanity will live in mega-cities spread across deltas vulnerable to the twin threats of submergence and subsidence. …

And what if climate refugees have no place to go?