In addition to robust multi-decadal warming, the globally averaged surface temperature exhibits substantial
decadal and interannual variability (Figure SPM.1a). Due to this natural variability, trends based on short
records are very sensitive to the beginning and end dates and do not in general reflect long-term climate
trends. As one example, the rate of warming over the past 15 years (1998–2012; 0.05 [–0.05 to 0.15] °C per