Nearly 75% of Global Population to Face Extreme Weather Changes in Two Decades

A study from the Center for International Climate Research (CICERO) in Norway suggests that rapid weather changes could affect 70% of the world’s population within the next two decades.

"In the best case, we calculate that rapid changes will affect 1.5 billion people," says Bjørn Samset, a physicist from CICERO.

This lower estimate would only be possible with drastic reductions in greenhouse gas emissions—something that has not yet been achieved.

Without such reductions, climate scientist Carley Iles and her colleagues project that dangerous weather changes will impact the majority of Earth's population.

Their research indicates that many of these changes are already inevitable.

"The only way to address this is to prepare for a situation with a much higher likelihood of unprecedented extreme events within the next one to two decades," Samset adds.

Evidence of these extremes is already visible.

Data from Europe's Copernicus Climate Service shows that the Earth just experienced the hottest Northern Hemisphere summer on record, surpassing last year's record. The Southern Hemisphere is also grappling with record-high winter temperatures.

This rise in global temperatures has led to devastating fires, floods, storms, and droughts, destroying crops and exacerbating food insecurity. These conditions also foster the spread of diseases.

"Like people living in a war zone, we are becoming desensitized to what should be alarm bells," said Jennifer Francis, a climate scientist at Woodwell Climate Research Center, in response to the Copernicus data.

Iles' team predicts that extreme weather events will escalate even more rapidly, increasing the likelihood of consecutive or simultaneous dangerous weather patterns such as extreme temperatures, rainfall, and winds.

For instance, dry lightning coupled with drought has intensified wildfires across the globe. In Pakistan in 2022, a severe heatwave was immediately followed by catastrophic flooding, affecting millions.

"Society is particularly vulnerable to rapid changes in extreme weather, especially when multiple hazards arise simultaneously," the researchers noted in their paper.

They highlight the compounding effects of heatwaves and extreme rainfall, which can lead to heat stress, crop failures, infrastructure damage, and reduced water quality.

Regions in the tropics and subtropics, home to the majority of the world's population, are expected to experience the most significant weather extremes under current high emissions scenarios.

"We focus on regional changes because they are more relevant to the experiences of people and ecosystems," says Iles.

While cutting emissions could mitigate some of these impacts, it may also create immediate challenges.

"Cleaning the air is essential for public health, but air pollution has been masking some of the effects of global warming," explains Laura Wilcox, a meteorologist at the University of Reading.

As air quality improves, the combined effects of reduced pollution and rising temperatures could trigger even stronger weather extremes, particularly in Asia.

Without urgent action, worsening weather extremes will impact most of the global population in the near future.

"These findings underscore the need for continued mitigation and adaptation to potentially unprecedented changes, even under a low-emissions scenario," Iles and her team conclude.