Heat. Wildfires. Torrential rain. Typhoons and hurricanes. Much of the northern hemisphere has been battered by extreme weather this summer.
Not all these events can be immediately linked to climate change. It can take a while for scientists to untangle what exactly is going on – plus, the planet’s natural weather and climate systems are powerful and also affect the weather.
But in the past few weeks, significant meteorological records have been broken in quick succession, to the concern of climate change experts.
As the summer draws to a close, let’s look back at what on earth happened – and how it is connected to climate change.
In the UK, the balmy days of early summer may feel like a distant memory after weeks of unsettled weather – but this year saw the UK’s hottest June on record.
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The average mean temperature, counting both days and cooler nights, was 15.8C. That eclipsed the previous record by 0.9C and was a significant jump in climate terms.
Record temperatures were reached in 72 of 97 areas of the UK where temperature data is collected.
Scientists at the Met Office said climate change made the chance of surpassing the previous record at least twice as likely.
In the first week of July, the planet saw its hottest day ever recorded when the average mean global temperature hit 17.23C. This broke the previous 2016 record of 16.92C.
In the Mediterranean, millions of people saw up close what extreme heat looks like. Two long and blistering heatwaves, named Cerberus and Caronte after ominous figures from ancient Greek mythology, struck countries across the region.
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*CO2e is a calculation for carbon emissions which includes greenhouse gases like methane.
In Italy, all cities were placed under red alert – and in Rome, tourists collapsed in temperatures above 40C.
In Athens, the Acropolis – Greece’s most popular tourist attraction – was forced to close to protect visitors from potentially fatal heat.
And in Algeria and Tunisia, temperatures climbed to 48C.
The extreme weather which has affected many millions of people in July is unfortunately the harsh reality of climate change and a foretaste of the future.
The heat created the tinder-dry conditions for wildfires that swept across the Mediterranean. Between 1 and 25 July, the huge fires in Greece emitted one million tonnes of carbon dioxide. That’s the most for any July wildfire in the country on record, and as much as London, one of the world’s most populous cities, emits in almost two weeks, according to 2019 figures.
By the end of the month, scientists with the World Weather Attribution group – which looks at the role of climate change in specific extreme weather events – had analysed the data and concluded that the heatwaves would have been “virtually impossible” without human-induced climate change.
Warming the atmosphere by burning fossil fuels has made the heatwave in southern Europe 2.5C hotter, they said.
El Niño, which began in June, could contribute to make 2023 the hottest year ever, scientists believe. The powerful natural phenomenon is linked to higher temperatures, and occurs every two to seven years when warm water rises to the surface in the Pacific off the coast of South America.
With millions desperate for relief from the heat, on 26 July record-breaking torrential rain and ferocious winds struck China and the Philippines. Typhoon Doksuri pounded cities and coastlines in East Asia for a week.
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More than one million people were evacuated as winds reached 240km/h (149m/h).
In the Chinese capital Beijing, the amount of rain that fell broke a 140-year-old record.
The floods damaged roads and bridges, submerged cars and destroyed construction sites.
In the Philippines, at least 26 ferry passengers died near Manila when they rushed to one side of a boat as it tilted in winds, causing it to capsize.
Warmer temperatures provide more favourable conditions for these types of storms.
In the months leading up to the typhoon, China, South Korea and other parts of East Asia had experienced record heat. Scientists with the World Weather Attribution group said that climate change made the July heatwave in China 50 times more likely.
On 8 August, the island of Maui in Hawaii faced a fire that became a deadly and terrifying ordeal.
On the waterfront town of Lahaina, people claimed that warning sirens failed to sound. Some fled into the ocean to try to save themselves from the rapidly moving flames.
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Much of the island was in drought and the dry vegetation provided ideal fuel for the flames to spread, fanned by raging winds from a passing hurricane.
The complex mixture of human systems and land management in Hawaii means that while climate change may have contributed to the fire, it is unclear how central its role was, say climate scientists and fire experts.
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Days later, on 19 August, a fire season that had started unusually early in eastern Canada raged in the country’s western province of British Columbia.
Fifteen thousand households were ordered to evacuate, while hundreds of miles north, a huge fire threatened the city of Yellowknife in Northwest Territories.
So far 15.6 million hectares (37.8 million acres) of land has burned across Canada – an area larger than New York state or England.
At least 1,000 fires are still burning as Canada lives through its worst wildfire season on record.
The way that humans manage forests are major contributors to fires. But climate change also fuels the conditions for flames to take hold – by drying out vegetation, causing earlier snow melt and warming ground that was previously too cold for fires.
Scientists expect that as global warming intensifies, wildfires will become more powerful.
A study by the World Weather Attribution group found that climate change made the hot, dry and windy conditions that drove wildfires in Quebec, Canada in June at least twice as likely and 20-50% more intense.
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On 21 August, a US state that is usually braced for wildfires – California – instead saw its first tropical storm in 84 years.
Storm Hilary, downgraded from a hurricane, made landfall in northern Mexico, killing at least one person when a family of five was swept into the sea, before moving up to California.
The storm put 26 million people in the state at risk of flooding, and 25,000 households across Los Angeles lost power as the storm moved through the city and caused flash floods.
Palm Springs saw the heaviest hour of rain ever recorded in the city, according to California’s governor.
In Death Valley, floodwaters filled the famously dry landscape, turning its valleys into rapid rivers.
It is too early to say if climate change made this storm more likely, but scientists say that higher temperatures will cause stronger hurricanes in future as more heat in the oceans creates more energy for storms.
The planet’s waters were hotter than ever this summer – a powerful marine heatwave broke the record for average global temperature. The heat that built up at the oceans’ surface could have helped to power strong hurricanes in the Atlantic in late August.
Storm Hilary is a reminder that the year is not yet over – the Atlantic hurricane season has only just started and is projected to be stronger than usual.
It’s no longer something in the future; we are really seeing it now.
The impact of extreme weather in different countries is a reminder that how humans respond is vital. This summer the UN and leading climate scientists again urged governments to keep to their promises to urgently tackle climate change.
Scientists say this summer is a sign of things to come as climate change worsens.