🥵 The heatwave phenomenon

Today's OneChart

According to the Berkeley Earth Temperature Report, a great source that tracks climate change metrics, the world has already warmed 1.3°C compared to the average between 1850 and 1900. The latter is frequently used as a benchmark for the pre-industrial period.

The effects of climate change were felt heavily in June and July when many countries across the globe, including those in Europe, experienced record-breaking temperatures.

Have you wondered why such intense heat extremes occur after “only” a 1.3°C increase?

Professor Stefan Rahmstorf, Head of Earth System Analysis at Potsdam Institute for Climate Impact Research, shared an insightful data chart on Twitter.

The chart illustrates that land surfaces have warmed much more than the ocean.

This is an integral insight because the global average temperature is made up of 70% ocean surface.

As well, Rahmstorf cites a new study that argues Europe is a heatwave hotspot.

This means the continent exhibits upward temperature trends that are three-to-four times faster compared to the rest of the northern mid-latitudes.

The reasons are changes in the jet stream.

• The researchers found that this accelerated trend is linked to atmospheric dynamical changes, which arise from an increase in the frequency and persistence of double jet stream states over Eurasia.
• Such double jet occurrences are particularly important for western European heatwaves, explaining up to 35% of temperature variability.