Written by Patryk Strzałkowski, journalist at Gazeta.pl.
It wasn’t just Poland that ended the summer with exceptional heat. On a global scale, and in Europe itself, it was record-breakingly hot - surpassing even last year’s record.
Scorching Heat and Extreme Weather
Temperature data from June to August was released by the European climate service, Copernicus. In August alone, the global temperature was 0.71 degrees Celsius higher than the average for that month. The average from 1991-2020 is already higher than the climate norms from before the era of global warming. Compared to pre-industrial times, August's temperature anomaly reached a staggering 1.51 degrees Celsius.
A difference of this magnitude may not seem significant because weather temperatures can fluctuate by several degrees in a single day. However, we’re talking about the global average, and a 1.5-degree increase over a century represents a huge shift.
In the past three months, the world has experienced the hottest June and August, the hottest day in history, and the hottest summer on record. This string of record-breaking temperatures increases the likelihood that the entire year 2024 will also set a record
- said Dr. Samantha Burgess, Deputy Director of Copernicus. She emphasized:
The extreme temperature events we witnessed this summer will become more intense and have increasingly devastating consequences for people and the planet unless we take urgent action to reduce greenhouse gas emissions.
Europe also saw record heat this summer - at least in most of the continent. Some parts of the British Isles, Iceland, and Portugal were cooler than usual. Most of the continent experienced a drier-than-average August, exacerbating droughts and fueling wildfires.
The Hottest Summer in History
The chart below shows that this summer (for the Northern Hemisphere) not only broke the record set in 2023, but also that the temperature anomaly was significantly higher than in previous years. The temperature was not only higher than the previous year, but also deviated greatly from previous decades. The chart also shows a clear trend of ongoing climate warming. The last ten years have been hotter than the previous decade, as well as significantly warmer than the 80s and 90s.
Recent temperature records continue not only a trend of global warming that has lasted for over 100 years but also a streak of records from the last 18 months. According to Copernicus, the 12-month period from September last year to August was 1.64 degrees Celsius hotter than the pre-industrial average (1850-1900). While 2023 was the hottest year on record, 2024 is very likely to surpass that record.
What’s causing this streak of the highest temperatures in recorded history? At the turn of last year and this year, the long-term trend of climate change was compounded by the natural El Niño phenomenon, a periodic warming of surface waters in the Pacific Ocean. Changes in the world’s largest ocean have such a significant impact on the planet that El Niño significantly raises the Earth's average temperature.
Now, the arrival of the opposite trend, La Niña, is expected - during which the surface of the tropical Pacific will cool for several months. This natural variability can be compared to the seasons - after summer comes winter, and every few years, the Pacific shifts into either El Niño or La Niña. But at the same time, the planet’s average temperature continues to rise due to our emissions of greenhouse gases. When these two effects overlap, we see temperature records. And even if 2025 or 2026 isn’t record-breaking, more records will eventually come - and will continue as long as we burn oil, gas, and coal, heating up the atmosphere.
The Hottest in 100,000 Years
The records reported by Copernicus relate to the history of measurements, which dates back to around the mid-19th century. So, has it never been hotter on Earth, even 500 or 1,000 years ago? Just because there were no thermometers doesn’t mean we have no idea about past temperatures. We can reconstruct them indirectly by studying trees, coral reefs, or ice cores.
These studies won’t tell us exactly what the global temperature was in August 5032 BC, but they do reveal trends over centuries and millennia.
Thanks to this, we know that global temperatures are breaking records not just from the past few hundred years but tens of thousands. Scientists believe that recent years are likely among the hottest in the last 100,000 years.
Climate Change Fuels Extreme Weather
The rise in average temperature shows us the trend and pace of climate change. However, the average temperature alone doesn’t tell us how this change affects our lives. This impact is becoming increasingly evident, as global warming destabilizes the weather and drives extreme events that cause significant damage and can threaten our lives and health.
Climate change fueled deadly heatwaves this summer in the Mediterranean, Mexico, and Asia; it was a key factor in the drought in Sicily and intensified Typhoon Gaemi and floods in Brazil.
In Poland, in addition to heatwaves, we saw record rainfalls in Warsaw and Zamość (where as much rain fell in one day as typically does in two months), as well as droughts. In Warsaw, the Vistula River reached a record low level of 24 centimeters. These two phenomena may seem contradictory, but they are not.
The record rainfall in the capital was preceded by weeks of intense heat and little rain. And while a massive downpour does little to improve the overall water situation, most of the water runs off quickly, and if there is no rain for the next week or two, the situation becomes extremely dry again. This is precisely the scenario scientists warn us about in relation to climate change: hot, dry periods interrupted by intense rainfall. Drought and flooding can follow one another.
How does global warming intensify extreme rainfall? Warmer air can "hold" more moisture. So the more we heat the planet by emitting gases from burning oil, coal, and gas, the more water there will be in the air - and the heavier the rain when it falls. For every degree Celsius of warming, the atmosphere can hold 7 proc. more moisture. When that moisture falls as rain, the downpour is more intense.
