UPDATED 6:59 AM EST, November 27, 2012
The warning came in a U.N. report released as climate talks intensified on Tuesday in Qatar.
The report says the dangers of carbon dioxide and methane emissions from warming permafrost are becoming an emerging issue among climate scientists. These dangers have so far not been factored in projections about future temperature rises.
Representatives from over 200 countries are negotiating a climate deal in Doha that would keep global temperatures from rising more than 2 degrees C (3.6 F) — compared to preindustrial times — by 2100.
