Explained: Scientists Say Heatwaves In US, Europe 'Virtually Impossible' Without Climate Change, What Does It Mean?

As heatwaves scorch North America and Europe, scientists have said these heatwaves would be "virtually impossible" without the human-induced climate change.

For the past one month, North America, Europe, and even China have witnessed record-breaking heat. The US city of Phoenix has recorded temperature above 43.3*C for 25 days straight. China, on the other hand, recorded its all-time highest temperature of 52.2*C. 

It is not just the intensity of heatwaves that is the cause of concern, but their frequency too. These extreme weather events take place amid grim forecasts for Earth's future, with the Intergovernmental Panel on Climate Change (IPCC) saying the humanity has just seven years to act to keep the global temperature rise below 1.5*C.

In its report last week, the World Weather Attribution (WWA) said these events would be very rare events without human-induced climate change. 

Here we explain what the report says and how North America and Europe are experiencing heatwaves. 

What does the report say on heatwaves and climate change?

The World Weather Attribution (WWA) in its report said that the heatwaves of sort currently scorching the United States and Europe would be "virtually impossible" without the human-induced climate change. 

In China, the heatwave would be once in 250 years event, according to the report. 

With climate change, however, heatwaves are becoming an annual affair, with the reporting noting that heatwaves are "amongst the deadliest natural hazards with thousands of people dying from heat-related causes each year".

"North America, Europe and China have experienced heatwaves increasingly frequently over the last years as a result of warming caused by human activities, hence the current heat waves are not rare in today’s climate with an event like the currently expected approximately once every 15 years in the US/Mexico region, once every 10 years in Southern Europe, and once in 5 years for China," says the report. 

The report singled out the burning of fossil fuels, such as coal, as a major source of global warming.

"Unless the world rapidly stops burning fossil fuels, these events will become even more common and the world will experience heatwaves that are even hotter and longer-lasting. A heatwave like the recent ones would occur every 2-5 years in a world that is 2°C warmer than the preindustrial climate," says the report.

The report calls for the urgent rolling out of heat action plans with an intersectional approach. It notes that factors like "intersecting trends of climate change, population ageing, and urbanisation" lead to increased vulnerability of climate change. 

Heatwaves in North America, Europe

Several parts of North America and Europe are currently witnessing a searing heatwave that has disrupted lives. 

In the United States, Phoenix in Arizona has recorded temperature above 43.3*C for 25 days straight. 

The heatwaves also often lead to wildfires, such as the one raging in Greece currently, which not just destroy natural vegetation, but also destroy homes, disrupts everyday life and business, and pumps smoke into the atmosphere that worsens air quality and triggers health conditions like asthma in at-risk people. 

The ABC News reports that 45 million across 12 US states are under heatwave alerts as of Tuesday. 

The weather forecast for Tuesday shows temperatures will reach or exceed 43.3*C in cities like Palm Springs, California; Phoenix, Arizona; and Las Vegas, Nevada, according to ABC, which added that temperatures around 37-40*C are expected from Texas to Nebraska. Elsewhere too, record-runs of high temperatures continue.

ABC reports, "Meanwhile, Tucson, Arizona, has been at or above 100 degrees [37*C] for 39 days, tying its record set in 2013. The city is expected to break that record on Tuesday...El Paso, Texas, has been on a record-smashing stretch of 39 straight days with temperatures at or above 100 degrees."

In Europe, the previous month of June was the hottest one on record, according to European Union (EU) scientists.

Last month smashed through the previous temperature record for the month of June -which was in 2019- by a substantial margin, reported Reuters, citing EU's Copernicus Climate Change Service. The service said the month was also very hot globally. 

Reuters reported, "Globally, June was just over 0.5C above the average temperature for the same month in 1991-2020, Copernicus said, as climate change pushes global temperatures to new records and short-term weather patterns also drive temperature movements."

Temperatures in Italy have hit 47*C. Dozens of wildfires are also raging in the country. In Greece, a third heatwave of the season is raging amid wildfires that have been  raging for around a week now. More than 500 wildfires have been witnessed as temperatures run over 40*C. Temperatures are also running above 40*C in Spain and France.

The Evening Standard reported, "Catalonia, northern Mallorca, Costa Blanca and the Costa del Sol in Spain have recorded temperatures of about 42C. In France temperatures have reached 40C in Hérault, Var, Gard, Vaucluse, Alpes-de-Haute-Provence, Bouches-du-Rhône, Alpes-Maritimes and on the island of Corsica."

The paper predicted that the heatwave may well extend into August. 

"The cause of the heatwave is a brand-new anticyclone called Charon...The scorching heat and high pressure system arrived in Europe from Algeria in the middle of July," reported Standard