InsideClimate: The melting of polar ice sheets and mountain glaciers will likely continue for thousands of years, causing irreversible sea level rise, even if global warming is limited to 2 degrees Celsius, according to a new report published last week during the climate negotiations in Paris. Sea levels could rise 13 to 33 feet or more unless far more ambitious steps are quickly taken to reduce greenhouse gas emissions, according to the report issued by the International Cryosphere Climate Initiative, a nonprofit...