Will you live an unprecedented life?

A new study published in Nature finds that today’s vulnerable youth will be most affected by continued greenhouse gas emissions.

May 7, 2025

Research led by climate scientists from the Vrije Universiteit Brussel (VUB) reveals that millions of today’s young people will live through unprecedented lifetime exposure to heatwaves, crop failures, river floods, droughts, wildfires and tropical storms under current climate policies. If global temperatures rise by 3.5°C by 2100, 92% of children born in 2020 will experience unprecedented heatwave exposure over their lifetime, affecting 111 million children. Meeting the Paris Agreement's 1.5°C target could protect 49 million children from this risk. This is only for one birth year; when instead taking into account all children who are between 5 and 18 years old today, this adds up to 1.5 billion children affected under a 3.5°C scenario, and with 654 million children that can be protected by remaining under the 1.5°C threshold. The study also highlights that children with high socioeconomic vulnerability face an even greater likelihood of unprecedented exposure to climate extremes in their lifetime. Deep cuts in greenhouse gas emissions are urgently needed to safeguard the lives of children all around the world.

Climate change's disproportionate burden on youth

Climate extremes, including heatwaves, crop failures, river floods, tropical cyclones, wildfires and droughts, will intensify with continued atmospheric warming. Today’s children will endure more climate extremes then any previous generation.

“In 2021, we demonstrated how children are to face disproportionate increases in extreme event exposure – especially in low-income countries. Now, we examined where the cumulative exposure to climate extremes across one’s lifetime will far exceed that which would have been experienced in a pre-industrial climate” says Wim Thiery, professor of climate science at VUB and senior author of the study.

“In this new study, living an unprecedented life means that without climate change, one would have less than a 1-in-10,000 chance of experiencing that many climate extremes across one’s lifetime” says Dr. Luke Grant, lead author and climate scientist at the VUB and Environment and Climate Change Canada (ECCC). “This is a stringent threshold that identifies populations facing climate extremes far beyond what could be expected without man-made climate change.” The threshold varies by location and type of climate extreme.

By combining demographic data and climate model projections of climate extremes for each location on earth, the researchers calculated the percentage of each generation born between 1960 and 2020 who will face unprecedented exposure to climate extremes in their lifetime (see Figure 1).

Figure 1: Living an unprecedented life – an illustration. The figure shows the cumulative number of heatwaves faced since birth by children born in Brussels, Belgium, in 2020 under three climate change scenarios, reaching 1.5°C (blue), 2.5°C (orange), and 3.5°C (red) global warming by 2100, respectively. The unprecedented exposure threshold (dashed grey line) is largely surpassed, implying that children in this location will face unprecedented lifetime heatwave exposure regardless of the scenario. © Grant et al., 2025, Nature

Generational impact of climate change

The younger a person is, the higher their likelihood of unprecedented exposure to climate extremes. Even if we successfully limit global warming to 1.5°C, 52% of children born in 2020 will face unprecedented heatwave exposure, compared to only 16% of those born in 1960. For heatwaves, the effect is particularly pronounced for those born after 1980, when climate change scenarios increasingly dictate exposure levels.

“By stabilizing our climate around 1.5 °C above pre-industrial temperatures, about half of today’s young people will be exposed to an unprecedented number of heatwaves in their lifetime. Under a 3.5 °C scenario, over 90% will endure such exposure throughout their lives”, warns Grant. “The same picture emerges for other climate extremes examined, though with slightly lower affected fractions of the population. Yet the same unfair generational differences in unprecedented exposure is observed.” Children in tropical countries will bear the worst burden under a 1.5 °C scenario. However, under high-emission scenarios, nearly all children worldwide face the prospect of living an unprecedented life (see Figure 2).

Figure 2: Children in tropical countries are relatively worse off under ambitious climate scenarios, while nearly every child around the world will face unprecedented lifetime heatwave exposure under high warming scenarios. **© Grant et al., 2025, Nature**

Climate vulnerability and social injustice

The study also highlights the social injustice of climate change and its impacts. Under current climate policies, the most socioeconomically vulnerable children born in 2020 will almost all (95%) endure unprecedented exposure to heatwaves in their lifetime, compared to 78% for the least vulnerable group. “Precisely the most vulnerable children experience the worst escalation of climate extremes. With limited resources and adaptation options, they face disproportionate risks”, says Thiery.

Urgent Need for Global Climate Action

Ahead of COP30 in Brazil, nations must submit updated climate commitments. Under current policies, global warming would reach around 2.7 °C this century. This study and the related Save The Children report emphasize the urgency of keeping global warming below 1.5 °C for the children of today and tomorrow.

Inger Ashing, CEO of Save the Children International, said: “Across the world, children are forced to bear the brunt of a crisis they are not responsible for. Dangerous heat that puts their health and learning at risk; cyclones that batter their homes and schools; creeping droughts that shrivel up crops and shrink what’s on their plates. Amid this daily drumbeat of disasters, children plead with us not to switch off. This new research shows there is still hope, but only if we act urgently and ambitiously to rapidly limit warming temperatures to 1.5 °C, and truly put children front and centre of our response to climate change.”

“With global emissions still rising and the planet only 0.2 °C away from the 1.5 °C threshold, world leaders must step up to reduce greenhouse gas emissions and lessen the climate burden on today’s youth”, concludes Thiery.

Numbers in overview

The numbers reported in the new study focus on one single birth cohort: children born in 2020. Climate extremes will affect all generations, but mostly children. Therefore authors provide below numbers that take into account all children who are between 5 and 18 years old today, which represents a total population of 1.69 billion children.

Heatwaves

Under a 1.5 °C pathway, 855 million children aged 5-18 in 2025 face unprecedented lifetime exposure to heatwaves.

Under a 2.7 °C pathway, 1353 million children aged 5-18 in 2025 face unprecedented lifetime exposure to heatwaves.

Under a 3.5 °C pathway, 1509 million children aged 5-18 in 2025 face unprecedented lifetime exposure to heatwaves.

Crop failures

Under a 1.5 °C pathway, 316 million children aged 5-18 in 2025 face unprecedented lifetime exposure to crop failures.

Under a 2.7 °C pathway, 400 million children aged 5-18 in 2025 face unprecedented lifetime exposure to crop failures.

Under a 3.5 °C pathway, 431 million children aged 5-18 in 2025 face unprecedented lifetime exposure to crop failures.

Wildfires

Under a 1.5 °C pathway, 119 million children aged 5-18 in 2025 face unprecedented lifetime exposure to wildfires.

Under a 2.7 °C pathway, 134 million children aged 5-18 in 2025 face unprecedented lifetime exposure to wildfires.

Under a 3.5 °C pathway, 147 million children aged 5-18 in 2025 face unprecedented lifetime exposure to wildfires.

Droughts

Under a 1.5 °C pathway, 89 million children aged 5-18 in 2025 face unprecedented lifetime exposure to droughts.

Under a 2.7 °C pathway, 111 million children aged 5-18 in 2025 face unprecedented lifetime exposure to droughts.

Under a 3.5 °C pathway, 116 million children aged 5-18 in 2025 face unprecedented lifetime exposure to droughts.

River floods

Under a 1.5 °C pathway, 132 million children aged 5-18 in 2025 face unprecedented lifetime exposure to river floods.

Under a 2.7 °C pathway, 188 million children aged 5-18 in 2025 face unprecedented lifetime exposure to river floods.

Under a 3.5 °C pathway, 191 million children aged 5-18 in 2025 face unprecedented lifetime exposure to river floods.

Tropical cyclones 

Under a 1.5 °C pathway, 101 million children aged 5-18 in 2025 face unprecedented lifetime exposure to tropical cyclones.

Under a 2.7 °C pathway, 163 million children aged 5-18 in 2025 face unprecedented lifetime exposure to tropical cyclones.

Under a 3.5 °C pathway, 163 million children aged 5-18 in 2025 face unprecedented lifetime exposure to tropical cyclones.

References:

Publication in Nature: https://www.nature.com/articles/s41586-025-08907-1

Save The Children Report: https://resourcecentre.savethechildren.net/document/born-into-the-climate-crisis-2-an-unprecedented-life-protecting-childrens-rights/

Contact

Prof. Dr. Wim Thiery:

wim.thiery@vub.be

https://bsky.app/profile/wimthiery.bsky.social

+32 2 629 30 29

Dr. Marie Cavitte:

marie.cavitte@vub.be

+32 470 19 24 15

The study was accomplished by researchers from Vrije Universiteit Brussel (VUB), Environment and Climate Change Canada, KU Leuven, the Royal Meteorological Institute of Belgium (RMI), and ETH Zurich.