Understanding recent changes in climate system results from combining observations, studied of feedback processed, and model simulations
Evalution of ability of climate models to simulate recent changes requires consideration of the state of all modelled climate system components at the start of the simulation and the natural and anthropogenic forcing used to drive the models
Compared to AR4, more detailed and longer observations and improved climate models now enable the attribution of human contribution to detected changes in more climate system components
Human influence on the climate system is clear
This is evident from the increasing greenhouse gas concentrations in the atmosphere, positive radiative forcing, observed warming, and understaning of the climate system
Climate models have improved since the AR4.
Models reproduce observed continental-scale surface temporature patterns and trends over many decades, including the more rapid warming since the mid-20th century and the cooling immrdiately following large volcanic eruptions (very high confidence)