What happens if the 1.5C target for global heating is missed?

The Guardian asks five climate experts to explain the key differences between 1.5C and 2C

The world's most ambitious climate target is under threat, both from physics and politics. But what would it mean for the planet and its inhabitants if humanity were to abandon the goal to limit global heating to 1.5C above preindustrial levels?

The inclusion of 1.5C (2.7F) was hailed as one of the great triumphs of the Paris climate agreement of 2015. Until then, international ambition had been limited to 2C (3.6F), much to the frustration of small island states and others on the frontline of climate disruption.