In what was largely seen as a final warning, the latest Intergovernmental Panel on Climate Change (IPCC) climate report cautioned that it's "now or never" if the world wants to prevent an irreversible climate disaster. As global leaders struggle to make meaningful changes, some of the world's most vulnerable nations are already facing the consequences of inaction. Roxy Koll, climate scientist at the Indian Institute of Tropical Meteorology and a lead author of the IPCC reports, joined us on Perspective to tell us more.