The 1.5°C overshoot has been in the news in the last few months, and COP30 recognised the need to minimise climate overshoot. Beyond the physical consequences, overshoot has ethical implications that are multi-generational. Understanding what it means is essential for shaping climate action that puts those most vulnerable at the centre. This blog explores what overshoot is, and what it means for children and for how we need to respond.
What does “1.5°C overshoot” actually mean?
The term “overshoot” is most often used to describe future temperature trajectories that exceed the Paris Agreement’s 1.5°C limit and then come back down to or below that level, consistent with the IPCC’s definition. Crossing the 1.5°C threshold doesn't refer to a single hot year. The Paris target is commonly defined over a 20-year average. Still, 2024 was the first year where the average global temperature exceeded 1.5°C above pre-industrial levels, and the period 2023-2025 was the first three-year period to exceed 1.5°C. Across IPCC scenarios, there’s a >50% chance of crossing 1.5°C between 2021 and 2040 (sooner under a high-emissions pathway).
Avoiding overshoot would have required immediate, rapid and deep emissions cuts this decade: global emissions should have peaked before 2025 at the latest. Given the continued delay in emission cuts, the hard truth is that a temporary overshoot of 1.5°C is now almost inevitable as the UN Secretary-General recently acknowledged.
Some of the big new questions therefore are:
• How high will the temperature overshoot go and for how long will it last? A 1.6°C world looks extremely different to a 2°C+ world, and will we keep overshoot to a couple of decades or will it last the rest of the century?
• What will be the damage while we’re above 1.5°C, and who/what will suffer most?
And for a question that is not even receiving much attention yet: if we later try to cool temperatures back down quickly, what might the consequences of that transition itself be?
Overshoot is a children’s crisis
At Save, we’ve helped make clear that climate change is a child rights crisis, and in an overshoot world, the everyday risks and impacts that children already face will intensify. What is more topical is that overshoot raises the likelihood of crossing climate tipping points: “points of no return” in parts of the climate system. Once crossed, changes in that part of the system keep going by themselves, even if temperatures later come down i.e. the changes are potentially irreversible on human timescales – including those of future generations, as systems that cross tipping points might require centuries or millennia to recover, if they ever do.
The latest Global Tipping Points Report and other science suggest we're entering a danger zone between 1.5°C and 2°C where several tipping points become much more likely. A “temporary” overshoot can push us into the temperature range where systems that children rely on could fail permanently. Two examples:
• Warm-water coral reefs. Reefs are already perilously close to temperature levels that threaten their survival at any meaningful scale. They’re estimated to support between 25-40% of marine species and over half a billion people (with the value of goods and services provided by coral reefs estimated at US$2.7 trillion per year, with US$36 billion of that in coral reef tourism). For children and their communities, reef collapse would mean less food, fewer jobs and less protection from storms.
• The Atlantic Meridional Overturning Circulation (AMOC) (often referred to as the “Gulf Stream”). For the UK and north-west Europe, the AMOC helps keep the climate relatively mild. Despite uncertainty, there is some evidence it could tip into a much weaker state this century, and this is considered a high-impact risk worth planning for. The impacts would be varied, severe and long-lasting, from more extreme winters to big risks to agriculture (earlier work suggests land suitable for arable farming in the UK could fall from 32% to 7%), with a range of knock-on impacts on health, nutrition, wellbeing, schooling, healthcare and family incomes.
For children, therefore, tipping points are about locking in inequality: they are a question of intergenerational justice.
Protecting children through deeper change
In an overshoot world, how we respond to climate risk and crises must evolve.
In programmatic work, we must build child-centred, transformative resilience
It is true that we need to continue building more “classic” resilience: helping children and their communities “bounce back” from a flood, drought or heatwave. Dealing with these events will require, for example, scaling up climate-smart health and nutrition programmes, resilient education systems, and child-sensitive social protection.
But this isn’t enough.
In an overshoot world (and even under current climatic conditions), climate change is not just delivering more extreme weather events. It is fundamentally changing what’s “normal”. For example, land that families have farmed for generations becomes too dry, salty or flood-prone to grow crops. Incremental changes in the agricultural sector (drought-resistant seeds, heat-tolerant livestock, drip irrigation) might buy time, but can fail once new climate normals exceed what they can withstand.
So we also need to build long-term, transformative resilience: helping communities (with children’s rights at the centre) to "bounce forward" into fundamentally new, more sustainable, equitable, and robust states. It goes beyond restoring the status quo (even an improved version of it) to redesigning systems so they can deal with fundamental shifts happening around them, and thereby ensure long-term wellbeing.
An example of that would be planning for deliberate livelihood transitions. Helping families move away from increasingly unviable, climate-exposed livelihoods (like rain-fed agriculture), so children’s futures aren’t tied to collapsing economies. It might look like region-wide shifts to diversified livelihoods co-designed with communities, backed by integrated interventions across sectors and scales: youth skills pathways, access to finance, new labour-market opportunities, social protection, and market regulation. The transformative element comes from intentionally changing a region’s development pathway, rather than incrementally protecting an increasingly fragile one.
Another example are services that move with people, which is not “add a mobile clinic”. It’s redesigning education, health and child protection systems for population mobility, for example through funding and rules that travel with families, portable entitlements, and fewer documentation barriers so displaced children can keep accessing care and school.
This is resilience that looks beyond the next hazard season (or even the next 5 years) and asks: what will make it possible for today’s children to build a life in 10, 20, 30 years’ time - even if the climate has deeply changed around them?
Humanitarian action needs to be anticipatory and transformative
Anticipatory action, short-term preparedness and early responses, whilst fundamental for dealing with climate-related shocks, can risk locking children and their communities into ever-worsening cycles of crises in places that are fundamentally changing. Humanitarian work will need to do two things at once:
1. Continue getting ahead of shocks with anticipatory action: for example, using forecasts and risk analysis to release resources before droughts, floods and cyclones hit.
2. Use crises/shocks as stepping stones towards structural change: link emergency support and recovery work to longer-term decisions about land use, urban growth, relocation, education pathways and livelihoods. Crises, such as climate shocks, should then be seen as catalysts to start or accelerate necessary, deep, and permanent structural changes towards long-term resilience. This work should be aligned with plausible, long-term climate futures, going beyond seasonal forecasts or even five-year outlooks. That includes planning for temperatures that exceed 1.5°C and later fall back down. Transitions themselves can create disruption: for example, if populations migrate during a period of exceedance and later try to return, the environmental, socio-economic and political conditions may no longer allow it.
All of this means being honest with partners, communities and with children themselves that the goal is not to preserve the status quo, but to stand alongside them as they navigate deep change, and to insist that these transitions happen in ways that are fair, ordered and protective of children’s rights. We also need to be honest that transformative resilience requires forward-looking, coherent planning and coordinated action across many stakeholders and spheres (e.g. humanitarian, development, climate); a patchwork of standalone projects developed in isolation will never be enough.
The choices we argue for, and how we talk about them
Even if global temperatures exceed 1.5°C for some time, this is not a licence to continue emitting greenhouse gases: every year of delay locks in more harm for children; every fraction of a degree matters. For Save the Children’s varied external engagement efforts, we would continue to keep children at the heart of climate ambition. We would keep pushing the UK government and other countries to slash emissions faster and continue fighting for climate finance that works for children globally.
Policies to limit overshoot and reduce emissions need to be integrated with broader social and economic reforms. In the UK, for instance, that means linking climate action to ending child poverty: warm homes, clean air, affordable transport, accessible green space and resilient schools.
We must be honest that every choice today shapes the kind of world children will inherit in 2050 or 2100. Choices about social and economic reforms will require thinking more about how we conceptualise a “good life” for children: less of what harms people and planet (e.g. empty consumption, pollution, inequality), and more of what helps children and their families to flourish (e.g. health, time, care, meaningful connection).
Within this, positive tipping points in social and economic systems, where beneficial changes become self-sustaining, offer some grounds for hope. History shows that once-marginal interventions, whether behaviours, technologies, or policies, can spread rapidly and reshape what is considered “normal.” Falling renewable energy costs are a powerful example of this. Our work, from campaigning to youth engagement to partnerships, can help trigger positive tipping points. For just one example, heat pumps are a key lever for decarbonising buildings: if supported by the right policies, finance and public trust, they can deliver warm, energy-efficient, and healthy homes for every child. In a world of inevitable overshoot, these positive tipping points are part of how we can bring us back down to 1.5 °C.
Overshoot will be a brutal chapter. The task now is to keep it as brief and shallow as possible, and ensure children will survive and outgrow it.
[Written by Lorena Pasquini with comments from Shruti Agarwal, Daljeet Kaur and Ruwayda Mohammed]
