The world is facing an increasing risk of "irreversible" climate shifts because worst-case scenarios warned of two years ago are being realized, an international panel of scientists has warned. Temperatures, sea levels, acid levels in oceans and ice sheets were already moving “beyond the patterns of natural variability within which our society and economy have developed and thrived,” scientists said in a report released Thursday. The findings came at the end of a three-day conference in Copenhagen, Denmark, where nearly 2,000 researchers gathered to discuss climate change.
