"Heatwaves impossible without climate change"

"Heatwaves impossible without climate change"

While we are grappling with Charon bis and the bad weather in Northern Italy, new data is arriving that should give us food for thought and raise awareness that the climate and health also depend on our behavior. Yes, because seven scientists from universities and meteorological agencies from the Netherlands, the United Kingdom and the United States have collaborated to assess the impact of climate change on these extreme events.

According to the data of World Weather Attribution (WWA), reaching such extreme temperatures would have been "statistically impossible" in the absence of man-made global warming.

Not only that: it is better to get used to these heat waves that we have been experiencing in recent months because - according to the experts - they are no longer unusual events, due to warming caused by greenhouse gas emissions. Indeed, future heat waves will be hotter and even more frequent if emissions are not rapidly reduced.


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A fiery July

Researchers from World Weather Attribution, a research group with several universities including theImperial College London and theRoyal Meteorological Institute of the Netherlands who studies the relationship between climate change and extreme weather events, examined climate trends in North America, Europe And China during the month of July concluding that the heat waves with temperatures above 45°C that occurred resulting in several casualties and fires would have been nearly impossible without climate change. The study also found that climate change has made a heat wave in China at least 50 times more likely.

computer simulations

Climate scientists use complex computer simulations to understand if climate change is causing an exacerbation and multiplication of extreme weather events. In order to quantify the effect of climate change on the recent rise in temperatures, WWA researchers analyzed weather data and computer model simulations to compare the current climate, after global warming of about 1.2°C since the late 1800s, with the climate of the past.

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Returning waves

The analysis focused on the periods when the heat was most dangerous in each region: average maximum temperatures for seven days in southern Europe, for 18 days in the United States western, in Texas It is in the Mexico northern and for 14 days in the plains of China. Scientists have discovered that heat waves like these are no longer uncommon, due to warming caused by the burning of fossil fuels and other human activities. Events of this type are expected about once every 15 years in North America, about once every 10 years in Southern Europe and once every five years in China.

Protect the most fragile

Heatwaves like these will become even more frequent and extreme if emissions are not quickly stopped and reduced to zero, scientists warn. If the temperature increase reaches 2°C – as it will in about 30 years, unless all Paris Agreement signatories fully implement current commitments to rapidly reduce emissions – events like this will become even more frequent, occurring every 2-5 years.

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"Heat is among the deadliest disasters. It is essential to increase warning systems, heat action plans and investments in long-term adaptation measures. This includes urban planning and strengthening critical systems such as health, electricity, water and transport," he said Julie Arrighiinterim director of the Red Cross Red Crescent Climate Centre. “To save lives in extreme heat, we need to address the most vulnerable people, including the elderly, people with poor health conditions, people without shelter and communities with limited access to cool spaces that can be a lifeline in extreme heat.”

Climate and polluting emissions

With analyzes like these it is finally possible to give substance to the affirmation that this anomalous heat (as well as the violent storms) are due to climate change. According to WWA experts, European and North American temperatures would have been virtually impossible without the effects of coal, oil and gas burning, deforestation and other human activities. Greenhouse gas emissions have made heat waves hotter than they otherwise would have been: Europe's heat wave was 2.5°C hotter, North America's 2°C and China's 1°C warmer due to climate change.

How hot is it in Italy

The WWA report doesn't go into detail about individual countries, but according to Cnr data, 2022 was the hottest year in Italy since 1800, that is, since we have enough data to make a comparison. The whole world is warming up, but the increase in the average temperature recorded in Italy is much higher than the global average. In 2022 alone, 310 extreme weather phenomena occurred in Italy, causing 29 deaths and having dramatic impacts on the economy and the environment. It is a 55% increase.

The return of El Niño

Experts admit that the return of the El Niño weather phenomenon is further amplifying the frequency and intensity of these extreme events because it leads to an increase in the surface temperature of the waters of thePacific Ocean east, which contributes both to an increase in cases of extreme temperatures and those of other exceptional meteorological phenomena. However, the researchers believe that the increase in global temperatures due to the burning of fossil fuels is the main reason heat waves are so severe.

It is not too late

In short, the outlined picture arouses concern so much that in some it could trigger the idea that it is now too late to reverse the trend. It's really like this? "The result of this attribution study is not surprising. The world hasn't stopped burning fossil fuels, the climate continues to warm, and heat waves continue to become more extreme. It's as simple as that," he replied. Friederike OttoLecturer in Climate Sciences at the Grantham Institute for Climate Change and Environment at Imperial College London.

“However, these heat waves are not evidence of climate collapse. We still have time to secure a safe and healthy future, but we urgently need to stop burning fossil fuels and invest in reducing our dependence on them. If we don't, tens of thousands of people will continue to die each year from heat-related causes. It is absolutely imperative that governments legislate on the phasing out of fossil fuels at this year's COP climate conference.”

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