Climate change: Shattering the temperature ceiling

Like in high jumping, where world records are old and only broken by centimeters – record heat should become rarer and margins smaller the longer we measure. Because of the rapidly warming climate, we observe the opposite – record temperatures have recently been shattered by large margins.

In high emission scenarios the probability of events with record margins like in 2003 or 2010 to occur anywhere in the Northern Hemisphere mid-​latitudes would increase from 4.5% per year in the recent past, to 22% in the coming decades. The probability of record-​shattering heat is determined by the warming rate, unlike the heatwave anomalies that relate to the total amount of warming. The probability of heat records is pathway depend and would decrease again if temperatures are stabilized.

Taking into account the observed weather of the last decades is no longer enough to prepare for the future. We need to factor in the rapidly warming climate and prepare for records that may look like “black swan” events based on the observations of the last few decades.