English: This diagram explains the difference between detecting changes in the climate system and attributing those changes to a particular cause. Detection involves identifying a climate trend or event (for instance, long-term surface air temperature trends, or a particularly extreme heat wave) that is strikingly outside the norm, including natural variations in the climate system. Similar to conducting forensic analysis on evidence from a crime scene, attribution involves considering the possible causes of an observed event or change, and identifying which is responsible for the observed behaviour.

In detection and attribution, the natural factors considered usually include changes in the Sun’s output and volcanic eruptions, as well as natural modes of variability such as El Niño and La Niña. Human factors include the emissions of heat-trapping "greenhouse" gases and particulates as well as clearing of forests and other land-use changes.

This image description is an edited quote from the cited public-domain source (Walsh et al., 2013).