Paris, Madrid, Athens and Mexico City have announced at the C40 conference of mayors on climate change held in Mexico their plans to ban diesel vehicles from their centres by 2025.

Scientists warn increasingly rapid melting could trigger polar ‘tipping points’ with catastrophic consequences felt as far away as the Indian Ocean.

Year 2015 marked a turning point for renewables. Led by wind and solar, renewables represented more than half the new power capacity around the world, reaching a record 153 Gigawatt (GW), 15% more than the previous year. Most of these gains were driven by record-level wind additions of 66 GW and solar PV additions of 49 GW.

High greenhouse gas levels mark start of new era of climate reality, according to World Meteorological Organization.