World in 'uncharted territory' as greenhouse gases hit new high: UN

Concentrations of carbon dioxide and other greenhouse gases in the atmosphere hit a new high in 2014, the UN said Monday, warning the resulting climate change was moving the world into "uncharted territory".

In its annual report on Earth-warming greenhouse gases in the atmosphere, the World Meteorological Organization said concentrations of carbon dioxide (CO2), methane and nitrous oxide once again broke records last year.