CLIMATE CHANGE: A THIRD OF 5-YEAR-OLDS WILL BE SPARED UNPRECEDENTED LIFETIME EXPOSURE TO DANGEROUS HEAT IF WORLD MEETS 1.5°C TEMPERATURE GOAL

Toronto, May 7, 2025 – Almost a third of today’s five-year-olds – about 38 million children – will be spared a lifetime’s “unprecedented” exposure to extreme heat if the world meets the 1.5°C warming target by 2100, Save the Children said.

Ahead of the 10th anniversary of the Paris Agreement, research released by Save the Children and Vrije Universiteit Brussel (VUB) found that under current climate commitments – which will likely see a global temperature rise of 2.7°C  above pre-industrial levels – about 100 million of the estimated 120 million children born in 2020, or 83%, will face “unprecedented” lifetime exposure to extreme heat.

However, if the world limits warming to the 1.5°C Paris Agreement target, this would reduce the number of five-year-olds impacted to 62 million – a difference of 38 million – highlighting the urgency to protect children through rapidly phasing out the use and subsidy of fossil fuels.

Dangerous heat is deadly for children, taking an immense toll on their physical and mental health, disrupting access to food and clean water and forcing schools to close.

Researchers defined an “unprecedented” life as an exposure to climate extremes that someone would have less than a 1 in 10,000 chance of experiencing during their life in a world without human-induced climate change.

The research, published in the report Born into the Climate Crisis 2. An Unprecedented Life: Protecting Children’s Rights in a Changing Climate also found that meeting the 1.5°C target would protect millions of children born in 2020 from the severest impacts of other climate related disasters such as crop failures, floods, tropical cyclones, droughts and wildfires.

The report found that, for children born in 2020, if global temperature rise is limited to 1.5°C rather than reaching 2.7°C above pre-industrial levels:

• About 38 million would be spared from facing unprecedented lifetime exposure to heatwaves;
• About 8 million would avoid unprecedented lifetime exposure to crop failures;
• About 5 million would be spared from unprecedented lifetime exposure to river floods;
• About 5 million would avoid unprecedented lifetime exposure to tropical cyclones;
• About 2 million would avoid unprecedented lifetime exposure to droughts;
• About 1.5 million children would be spared unprecedented lifetime exposure to wildfires.

Climate extremes – which are becoming more frequent and severe due to climate change – are increasingly harming children, forcing them from their homes, putting food out of reach, damaging schools and increasing risks like child marriage as they are forced out of education and into poverty and food shortages.

Denise*, 16, and her family were forced from their home in Brazil when the country’s worst floods in 80 years devastated their community last year. Their home, including Denise’s bedroom, was severely damaged, and she was out of school for nearly two months.

She said: “It really affected me mentally, and academically too. Catching up on all my grades to pass secondary school was really tough, especially at a state school. It massively impacted my schoolwork. My grades dropped significantly after the floods.”

Children impacted by inequality and discrimination and those in lower-and middle-income countries, are often worst affected. Meanwhile they have fewer resources to cope with climate shocks and are already at far greater risk from vector and waterborne diseases, hunger, and malnutrition, and their homes are often more vulnerable to increased risks from floods, cyclones and other extreme weather events.

Haruka, 16, whose poem is featured in the report, is from Vanuatu, which recently experienced three of the most severe types of cyclone in just a year. She said: 

“Cyclones are scary. For me, they continue to destroy my home, every year – we don’t even bother trying to fix the ceiling anymore. 

“The past few years, I’ve seen ceaseless destruction and constant rebuilding. This seemingly never-ending cycle has become our reality, and most people aren’t even aware that it’s not just nature doing its thing, but it’s us bearing the brunt of a crisis that we did not cause.” 

As well as comparing conditions under 1.5°C and 2.7°C scenarios, the report also examines a scenario in which global temperatures rise to 3.5°C by 2100, which will lead to about 92% of children born in 2020 – about 111 million children [5] – living with unprecedented heatwave exposure over their lifetime.

While we need a rapid phase-out of the use and subsidy of fossil fuels to stick to the 1.5°C target, we must not lose sight of solutions, Save the Children said. The report highlights initiatives like increased climate finance, child-centred and locally led adaptation and increasing the participation of children in shaping climate action.

Danny Glenwright, President and CEO of Save the Children, said:

“Children around the world are paying the highest price for a crisis they had no hand in creating. Scorching heat threatens their health and ability to learn, intense storms tear apart their homes and schools, and droughts leave them with empty plates. In Canada, relentless wildfires, extreme heatwaves, and melting ice are putting entire communities, particularly rural and Indigenous communities, at risk.

Children are sounding the alarm — and we must listen. This new research shows there is still hope, but only if we act with urgency, ambition, and courage. We must rapidly limit warming to 1.5°C and put children’s rights, voices, and needs at the heart of every climate decision we make.”

As the world’s leading independent child rights organisation, Save the Children works in about 110 countries, tackling climate across everything we do. Save the Children supports children and their communities globally in preventing, preparing for, adapting to, and recovering from climate disasters and gradual climate change. We have set up floating schools, rebuilt destroyed homes and provided cash grants to families hit by disasters.

We also work to influence governments and other key stakeholders on climate policies, including at the UNFCCC COP summits, giving children a platform for their voices to be heard.

ENDS

NOTES TO EDITORS 

Summary of Save the Children’s recommendations: 

Leaders must:

• Take ambitious and urgent action now to limit warming to a maximum of 1.5°C above pre-industrial levels, including by rapidly and equitably phasing out the use, subsidizing and financing of fossil fuels, with high-income and historically high-emitting countries leading the way.
• Urgently close the adaptation gap and provide loss and damage funding through the provision of new and additional climate finance, prioritizing children and child-critical social services, with a particular focus on reaching children most at risk. Climate finance should be delivered primarily in the form of grants, particularly for adaptation and loss and damage.
• Children, their rights, voices and unique needs and vulnerabilities must be centred in international climate plans and agreements, including the upcoming submission of new Nationally Determined Contributions (NDC 3.0), as well as building and investing in the climate resilience of child-critical services such as health and nutrition, water, sanitation and hygiene (WASH), education, child protection, and social protection.

Endnotes: 

[1] For this research, scientists have defined a heatwave as: when the daily Heat Wave Magnitude Index of that year exceeds the 99th percentile of pre-industrial Heat Wave Magnitude Index distribution for the specific climate model grid cell. The Heat Wave Magnitude Index measures how intense a heatwave is during a year. It looks at the hottest stretch of at least three days in a row when temperatures are much higher than what was normal before industrial times. The higher the number, the more extreme the heatwave.

[2] Ten years ago, world leaders at the UNFCCC COP21 summit in Paris agreed on a long-term goal to limit global temperature rise to 2°C above pre-industrial levels by 2100. The treaty also states that preferably this would be limited to below 1.5°C.

To achieve these emissions reductions, signatories to the Paris Agreement must pledge NDCs and update these every five years. According to the latest available data, the pledges currently being implemented will see global temperatures rising to 2.7°C above pre-industrial levels by 2100. We also look at a 3.5°C scenario, a near-worst-case outcome that assumes continued high emissions and insufficient mitigation efforts which is worryingly close to the 3.2°C warming we are currently headed towards.  Both these scenarios will have an unacceptable and deadly impact on children.

Some signatories to the Paris Agreement submitted new NDCs earlier this year, but many are delayed in their submission and the full picture won’t be available before the end of 2025.

[3] This new report follows a groundbreaking report from 2021 looking at the projected increase in climate extremes faced by children.

[5] 111 million is 92% of the 2020 birth cohort of about 120 million children. Global emergence of unprecedented lifetime exposure to climate extremes, the research underpinning this report.

Methodological note

This report is a collaborative product, with significant contributions from researchers from Vrije Universiteit Brussel, Save the Children experts, and a child reference group of 28 children from Colombia, Vanuatu, New Zealand, Ukraine, Albania, Sierra Leone, China and Yemen who ensured a comprehensive and child-centred perspective on climate action. The findings on climate risks and its impacts are based on five data analysis sources from Vrije Universiteit Brussel, including newly generated simulations of climate impacts across six climate extremes (heatwaves, crop failures, river floods, tropical cyclones, droughts, wildfires), and global mean temperature scenarios based on Intergovernmental Panel on Climate Change (IPCC) 6 th Assessment Report Scenario Explorer [i].

Moreover, country-level life expectancy provided by the United Nations World Population Prospects, population reconstructions and projections by the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) database, and country-scale cohort size data provided by the Wittgenstein Centre for Demography and Global Human Capital’s Data Explorer were used in the analysis. The research methodology integrates these diverse datasets to calculate the lifetime exposure of people to climate extremes in 177 countries, across regions and globally. This is achieved by mapping the projected climate extremes along various global mean temperature trajectories, which are then crossed with life expectancy and population data to calculate conservative estimates of the lifetime exposure to climate extremes for different generations of people.

The context for this analysis is provided by the initial set of climate action commitments (Nationally Determined Contributions) announced following the Paris Agreement. The findings 34 highlight intergenerational inequalities in exposure to climate extremes and underscore the critical need for robust climate action to minimise impacts on children and future generations. The extent to which current and future generations will experience a warmer and, as a result, a different world with greater climate impacts depends on the choices we make now, which will shape future greenhouse gas emission scenarios, ranging from the optimal situation of very low emissions to the extreme case of very high emissions [ii].

The analysis refers to three global warming scenarios by the year 2100, compared to pre-industrial temperatures:

• a 1.5°C scenario, which aligns with the ambitious objective of the Paris Agreement and requires significant and rapid reductions in greenhouse gas emissions.
• a 2.7°C scenario, which reflects the expected heating based on current mitigation policies and pledges, as estimated by the Climate Action Trackerl [iii] .
• a 3.5°C scenario, a near-worst-case outcome that assumes continued high emissions and insufficient mitigation efforts.

These scenarios are crucial for modelling and comparing the potential long-term impacts of the climate crisis on populations, and emphasize the urgency of taking action to mitigate future climate risks.

To assess how socio-economic vulnerability exacerbates unprecedented lifetime exposure to heatwaves, the study employs two indicators. In addition to gross domestic product (GDP), the analysis relies on the Global Gridded Relative Deprivation Index (GRDI), which rates multidimensional deprivation and poverty through a combination of factors including the ratio of children to working-age population, infant mortality rates, human development levels, and the contrast between rural and urban populations. While these indicators do not directly account for potential adaptations to climate change, they provide insight into the current capacity of populations to adapt. The study then maps the unprecedented exposure to heatwaves of the 20% most and least vulnerable as indicated by GDP and GRDI across the three global warming scenarios mentioned above for different generations.

It is important to acknowledge that climate and impact models such as the ones this analysis is based on – while invaluable for projecting future climate scenarios – have inherent limitations and uncertainties. These models produce simulations that rely on a mathematical representation of the climate that is limited by the models’ spatial resolution, and what these attempt to project into the future is historical data that may have gaps and may not fully capture future climate conditions. The rate of climate warming is influenced by complex interactions between emissions and various processes that can either mitigate or amplify atmospheric climate cycles. Scientists remain uncertain about several factors, such as the interaction between water vapour and aerosols in cloud formation, which may have cooling or warming potential, and they cannot predict natural phenomena like volcanic eruptions. Additionally, potential tipping points in the climate system and the unpredictable nature of human behaviour add layers of uncertainty. These complexities highlight challenges in predicting precise climate scenarios especially over the longer-term, underscoring the need for adaptive and flexible climate strategies.

The findings on promising responses to climate risks for children and good practices in child-centred or child-responsive, locally led adaptation are based on a systematic scoping of evidence. This review focused on the most promising responses to climate risks for children across six priority sectors for Save the Children’s climate work: health, WASH (water, sanitation 35 and hygiene), education, child protection, food and nutrition security and livelihoods, and social protection. It was conducted by Lezlie Morinière and Charlotte Gendre of Integrated Risk Management Associates LLC (IRMA).

Additional data:

*Children born in 2020 (“today’s five-year-olds”), measured against the 2020 birth cohort of about 120 million.

Example interpretation of the table: Under a 1.5°C compatible warming pathway, about 62 million children born in 2020 will experience unprecedented lifetime exposure to heatwaves, corresponding to 52% of all children born in 2020.

NB: Numbers in the table have been rounded up or down to the nearest integer. Please note that all these figures and the 120 million total birth cohort are all approximations and rounded up/down. Exact figures are available on request.

Please note that all these figures are based on predictive modelling from scientists at VUB.

[i] Edward Byers, Volker Krey, Elmar Kriegler, Keywan Riahi, Roberto Schaeffer, Jarmo Kikstra, Robin Lamboll, Zebedee Nicholls, Marit Sanstad, Chris Smith, Kaj-Ivar van der Wijst, Alaa Al Khourdajie, Franck Lecocq, Joana Portugal-Pereira, Yamina Saheb, Anders Strømann, Harald Winkler, Cornelia Auer, Elina Brutschin, Matthew Gidden, Philip Hackstock, Mathijs Harmsen, Daniel Huppmann, Peter Kolp, Claire Lepault, Jared Lewis, Giacomo Marangoni, Eduardo Müller-Casseres, Ragnhild Skeie, Michaela Werning, Katherine Calvin, Piers Forster, Celine Guivarch, Tomoko Hasegawa, Malte Meinshausen, Glen Peters, Joeri Rogelj, Bjorn Samset, Julia Steinberger, Massimo Tavoni, Detlef van Vuuren. AR6 Scenarios Database hosted by IIASA. International Institute for Applied Systems Analysis, 2022.

[ii] IPCC, 2023: Summary for Policymakers. In: Climate Change 2023: Synthesis Report. Contribution of Working Groups I, II and III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, H. Lee and J. Romero (eds.)]. IPCC, Geneva, Switzerland, pp. 1-34, doi: 10.59327/IPCC/AR6-9789291691647.001.

[iii] Climate Action Tracker (2024). 2100 Warming Projections: Emissions and expected warming based on pledges and current policies. November 2024. Available