UN sounds clarion call over humans 'irreversible' impact on climate

The UN panel on climate change sounded a dire warning on Monday, saying the world is dangerously close to runaway warming - and that humans are "unequivocally" to blame.

Already, greenhouse gas levels in the atmosphere are high enough to guarantee climate disruption for decades if not centuries, scientists warn in a report from the Intergovernmental Panel on Climate Change (IPCC).  That’s on top of the deadly heat waves, gargantuan hurricanes and other weather extremes that are happening now, and are likely to become more severe.