Physicist Gabriella Greison: Heat has existed before, but today records are being broken more often and with greater intensity

Record heat waves have once again brought back the familiar saying that “It was hot even 40 years ago.” Italian physicist Gabriella Greison says this claim is only partly true and is not enough to explain what is happening with climate change.

According to her, the core of the problem does not lie in the fact that there were very hot days in the past as well, but in the reality that temperature records are now being exceeded more and more often, by larger margins, lasting longer and occurring simultaneously in different regions of the world.

Greison explains that the climate does not behave like a thermometer, where mercury rises in a linear way, but like a complex system influenced at the same time by the atmosphere, the oceans, the ice, air currents and the land. For this reason, even a small increase in the average temperature can significantly raise the likelihood of extreme phenomena such as heat waves, droughts and storms.

She also underlines that climate change is driven by self-reinforcing mechanisms. As an example, the physicist mentions dry soil, which evaporates less water, loses less heat and, as a result, becomes even hotter, creating a cycle that worsens temperatures.

“Climate change denial often stems from a mistaken way of understanding the climate, by focusing on individual events rather than on the behavior of the entire climate system,” Greison says.

“The main challenge is not only temperature, but the growing amount of energy that the climate system is accumulating,” she adds.

According to her, reducing greenhouse gas emissions, increasing energy efficiency, as well as investing in next-generation nuclear energy and renewable sources are essential to limit global warming.