As the human-caused climate change persists, the harmful heat levels that have scorched the northern hemisphere this summer are projected to rise three to 10 times more frequently globally by the turn of the century.

The study, published in Communications Earth & Environment on Thursday by experts from Harvard University and the University of Washington, indicates this rise is expected to occur in mid-latitude countries such as the United States, China, Japan, and Western Europe, as reported by CNN. The term "dangerous heat" refers to temperatures of 39.4 degrees Celsius (103 degrees Fahrenheit) or above.

The number of dangerously hot temperatures in this region will more than double by 2050.

Deadly heat waves are currently unusual in the mid-latitudes, but they are anticipated to become more common in this region. According to the research, severe heat waves are expected to increase 16-fold in Chicago by 2100.

The Tropics Are in Grave Danger

The situation will be far worse in the tropics, where people may be subjected to deadly heat for the majority of the year. Days of "extremely dangerous heat," classified as 51 degrees Celsius (124 degrees Fahrenheit), might double. According to experts, those temperatures stretch the boundaries of human survival.

The projections were made under the assumption that average global temperatures will rise by 2 degrees Celsius, a cap set out in the 2015 Paris Agreement. The agreement says that a lower goal of 1.5C of warming is preferable, and there is growing momentum for the world to keep to 1.5C by making deeper and quicker cuts to greenhouse gas emissions.

The study's lead author Lucas Vargas Zeppetello from Harvard University noted that the "record-breaking heat events of recent summers will become much more common in places like North America and Europe."

"For many places close to the equator, by 2100 more than half the year will be a challenge to work outside, even if we begin to curb emissions," he stated in a press release.

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According to Simon Bradshaw, research director of the Climate Council in Australia, the world is already on a path toward 3 degrees Celsius of warming, but there is still time to limit the agony locked in for future generations.

However, per Sunshine Coast News, Bradshaw stated that significant action would be taken within the next 10 years because sea levels "will continue to rise for centuries or millennia."

"But when it comes to extreme heat, if we get emissions plummeting this decade, then as early as 2040 we'd start to see fewer deadly heat waves than we'd otherwise see. It really drives home the gravity of the actions we take now," he stated.

Arnagretta Hunter, a cardiologist and physician with the Australian National University's medical school, underscored that "Climate change is the greatest health challenge we will face this decade" and it has already impacted the lives of more than 50 percent of the Australian population "through Black summer and the recent catastrophic floods."

"It is time to use our scientific understanding of the relationship between the environment and human health, coupled with imagining the increase in extremes that are likely over the coming decades. This combination of science and imagination is key to climate adaption," Dr. Hunter said.

Nightmarish Situation for Millions of People

So far, the Earth has warmed by about 1.2 degrees Celsius, and current projections based on countries' carbon-cutting pledges show that the globe will substantially surpass the Paris Agreement's 2 degree Celsius objective for 2100, let alone its more ambitious 1.5 degree Celsius target.

Zeppetello and colleagues examined forecasts from global climate models, human population projections, and the relationship between economic growth and carbon emissions in their study.

They projected that there is just a 0.1 percent possibility of constraining global average warming to 1.5 degrees Celsius by 2100 and that the planet is likely to hit 1.8 degrees Celsius by 2050, as per a report from GMA News.

The researchers discovered that the most likely worldwide average temperature rise in 2100 will be 3 degrees Celsius, which Zeppetello described as "nightmarish" for many people.

In the direst situation, he warned, if emissions continue unabated, extreme heat in the tropics may persist for up to two months each year.

However, he stated that the future scenario depends on how soon mankind can reduce emissions.

"We don't have to go to that world. There's nothing right now that says it is a certainty, but people need to be aware of just how dangerous that would be if it were to pass," Zeppetello said.

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