Why are there such big differences in projections between different climate models?

Each climate model is constructed differently and represents climate processes in different ways.

In detail

The general priniciples of modelling the climate are the same but different climate modeling centres often use different methods of representing climate processes. This can cause large variations in the resulting projections. See Box 2.1 of Climate projections report.

For some projections, different climate models are in agreement (e.g. changes in global mean temperature). For other projections, particularly where time and space scales are decreased, significant differences can result (e.g. changes in regional seasonal precipitation).

Find out more

• IPCC website