More than 40% of children under the age of 10 globally are already experiencing at least 20 additional “heat-stress days” due to climate change.

This is according to a new attribution study, published in Science Advances, which combines climate models with demographic data to assess the age groups and regions that are exposed to the most hot, humid days.

The study finds that children up to the age of nine already face more additional heat-stress days globally as a result of climate change than any other age group.

It adds that south Asia and west Africa are recording the greatest childhood exposure to dangerous levels of humid heat – largely because these regions have a rapidly growing population with the highest proportion of young children.

As the climate warms, children will continue to be more exposed to heat stress than any other age group, the paper warns.

The lead author of the study tells Carbon Brief that the findings should inform discussions about climate justice, noting that children in developing countries “have contributed the least to historical greenhouse gas emissions”.

Humid heat

High temperatures can be deadly. For example, the heatwaves that swept across Europe in the summer of 2026 have been linked to tens of thousands of “excess deaths”.

A prominent 2021 study found that children born in the 21st century will be exposed to more extreme weather events in their lifetimes than their parents and grandparents.

Four years later, a study conducted by scientists from the same team found that more than half of children born in 2020 – around 62 million people – will experience “unprecedented lifetime exposure” to heatwaves, even if warming is limited to 1.5C.

Now, the latest research from the same team finds that children already face greater exposure to dangerous levels of humid heat than adults as a result of human-caused climate change.

Extreme heat is particularly dangerous when combined with high humidity. In hot weather, the human body produces sweat to cool itself down. However, as humidity increases, sweating becomes less effective.

The study uses wet-bulb globe temperature – a measure of temperature that takes humidity and wind into account – to calculate heat stress. It defines a “heat-stress day” as any day with a wet-bulb globe temperature above 28C, as this is considered the threshold for “moderate heat stress”

The authors then use climate models to simulate global temperature patterns in the present-day climate. (The authors use the climate of 2023, in which human activity has caused 1.3C of warming, to represent the “present-day”.)

They then count the number of heat-stress days that each country records on average, per year. The authors then repeat this exercise, simulating a pre-industrial climate without human-caused warming.

By comparing the number of heat-stress days in the present-day climate with the number in a pre-industrial climate, the authors can determine how many extra heat-stress days were driven by climate change. They refer to these as “extra” or “attributable” heat-stress days.

The authors find that “low-latitude” countries, located in the tropics, record the most extra heat-stress days.

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For example, the paper finds that people living in Côte d’Ivoire currently face 112 heat-stress days every year. It adds that around half of these are due to human-caused climate change.

In contrast, Germany sees only 0.1 heat-stress days per year in today’s climate on average, which is largely attributable to human-caused climate change.

Rosa Pietroiusti, a PhD student at Vrije Universiteit Brussel and lead author on the study, explains why this number may seem lower than expected.

She tells Carbon Brief that the paper “really focuses on humid heat, at levels that are relatively rarely felt in Europe”. She adds:

“Our data also doesn’t capture the urban heat island effect, due to the resolution of the data we use, which also would lead to underestimations of heat stress locally, and lead to a mismatch with what people are experiencing at local scales, particularly in cities.”

Inequality

Extreme heat affects some people more severely than others. Children, people over 65 and those with pre-existing medical conditions or certain disabilities are among the most vulnerable. This is because their bodies are less able to regulate their temperature.

The authors use gridded demographic data to determine the age structure of each country. From this, they calculate how many people from each age cohort are exposed to extra heat days as a result of climate change.

The research finds that globally, 583 million children under the age of 10 already live through at least 20 attributable heat days every year. This accounts for 44% of all children in this age bracket.

In comparison, 190 million people aged 60-69 face at least 20 attributable heat days per year, accounting for 30% of this age cohort.

The authors find that children face the greatest exposure to humid heat for two main reasons.

First, there are more young people alive today than older people, with 1.3 billion children aged under 10 in the world, compared to 0.6 billion people aged 60-69.

Second, they find that countries in Africa and Asia typically have rapidly growing populations with more young children. In contrast, many countries in the northern hemisphere – which are typically cooler – have older populations.

The map below shows how many extra stress heat days each country currently faces as a result of human-caused climate change. Darker reds indicate a higher number of attributable heat days. The blue circles show the percentage of the population under the age of 10, with larger circles indicating a higher percentage.

Warming world

The authors also repeat their analysis for a 1.5C and 2C warmer world. They use population estimates from the SSP2 scenario, which projects that the world’s population will peak at more than nine billion in the second half of the 21st century, with most growth occurring in low-latitude regions – especially in sub-Saharan Africa.

The research finds that, in today’s climate, 11% of all under 10s currently experience 100 or more extra heat-stress days per year due to climate change. In worlds warmed by 1.5C and 2C, the percentage rises to 13% and 23%, respectively.

In contrast, only 6% of all people aged 60-69 currently face 100 or more extra heat-stress days each year due to climate change. This number rises to 9% and 17% for 1.5C and 2C worlds, respectively.

These results are shown in the plot below. The three rows represent the climates of 2023 (top), a 1.5C world (middle) and a 2C world (bottom). The columns show different age cohorts, from the oldest on the left to the youngest on the right.

Each circle contains 100 coloured dots, with each dot representing 1% of the age cohort.

The colour of the dot represents exposure to annual heat-stress day, with darker dots indicating more heat-stress days. Grey dots mean that people experience fewer than one extra heat-stress day per year due to human-caused climate change, while black dots mean more than 150 extra heat-stress days due to climate change.

The figure shows that higher warming levels expose more people to heat stress and that younger cohorts tend to be worst affected.

For example, the top-right circle represents heat stress for under 10s in the present-day climate. Three of these dots are coloured black, indicating that 3% faced at least 150 attributable heat-stress days in 2023.

Pietroiusti tells Carbon Brief the study uses wet-bulb temperature because it is a “well-established heat stress metric”. However, she notes that it was not “explicitly defined to focus on children”. She continues:

“A really important step forward in the research community would be to link up climate science and health science experts to do research on what metrics are really most representative of, for example, health impacts and educational impacts that children will be suffering.”

Vulnerability

Dr Qinqin Kong, a postdoctoral researcher at the departments of medicine and health policy at Stanford University, who was not involved in the study, praises its “robust” methodology.

He tells Carbon Brief that the research provides “a timely quantitative evidence for discussions of climate justice, children’s rights and intergenerational equity”.

However, Kong suggests that the paper “may overstate the contrast between children and the elderly and underestimate the relative burden of older adults”.

He says:

“The elderly may also be more vulnerable due to their social circumstances. Children often benefit from parental supervision and caregiving, whereas many older adults live alone, have limited mobility and face barriers to accessing cooling or emergency assistance during heat events.”

Kong also notes that “people and societies in the mid-latitudes [for example, across much of Europe and North America] are less adapted to heat”, which may make them vulnerable to its impacts.

For example, he says that Europe “shows substantially stronger relative risk of heat mortality likely due to less heat-acclimatised populations, lower air conditioning prevalence and urban designs that don’t favour heat dissipation”.

Similarly, Dr Daniel Vecellio – a researcher at the University of Nebraska, who was not involved in the study – tells Carbon Brief that children are an “understudied cohort”.

However, he says there is “reason for hope” because “children are typically pretty good behavioural adapters to extreme heat” and because people who are “chronically exposed to extreme heat” will “have a better chance at better acclimatisation”.

Pietroiusti tells Carbon Brief that global reporting on heatwaves is often skewed towards wealthier nations.

For example, she notes that large-scale databases of disasters, such as EM-DAT, often underrepresent heatwaves in Africa, due in part to a lack of news coverage and formal reporting. She adds:

“Studies like this, which start from the climate data, can start to fill some of these gaps.”

She adds that the paper should inform discussions about climate justice, noting that children in developing countries, who are most severely affected by the increase in heat-stress days, “have contributed the least to historical greenhouse gas emissions”.

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Attribution

The post Climate change exposes 580 million children to 20 extra ‘heat-stress days’ every year appeared first on Carbon Brief.

Climate change exposes 580 million children to 20 extra ‘heat-stress days’ every year

The US is expected to resume its attempt to sink measures for a greener global shipping sector at closed-door talks between governments at the International Maritime Organization (IMO) in early September.

The US and oil-producing allies like Saudi Arabia want to weaken a proposed plan for cleaner fuels that aims to reduce planet-heating emissions from the industry, which relies heavily on dirty bunker fuels. Shipping currently represents 3% of global emissions.

Those that want a softer system are likely to back a Liberian proposal which expert analysis suggests would see emissions fall by only half at most by 2050, far short of the sector’s agreed climate goals.

After several years of debate, governments provisionally agreed in April 2025 on the “Net Zero Framework” (NZF), a series of emissions reduction targets for shipowners, backed up with financial rewards for meeting the targets and fees for missing them.

But in October 2025, after a high-profile intervention from US President Donald Trump and threats of sanctions and visa restrictions, the US convinced a majority of voting nations to postpone the adoption of the NZF for a year.

Ralph Regenvanu, climate minister for the Pacific nation of Vanuatu, called the delay “unacceptable” given the urgency of accelerating climate change.

After a round of low-profile talks in May, the first of three further sets of talks on how to clean up shipping will begin at the IMO’s riverside headquarters in London on Tuesday, culminating in a final public session in November.

Em Fenton, who follows the talks as senior director of climate diplomacy at Opportunity Green, an NGO focused on aviation and shipping, said governments should not be sidetracked by alternative proposals to the NZF, calling them “a distraction from a hard-fought multilateral compromise”.

“If countries want to deliver a just and fair maritime transition, there is really only one choice: back the NZF and stand together in solidarity against those who would tear it apart,” Fenton added.

Five proposals on the table

Governments will discuss five different proposals submitted in advance of next week’s meeting. The most ambitious of these is from the Pacific island nation of Tuvalu, which has proposed a levy on the entirety of a ship’s emissions rather than just those above a certain level, as the NZF envisions.

That had been the original demand of Pacific nations before the NZF was provisionally adopted in April 2025. At the time, Tuvalu’s transport minister Simon Kofe described the NZF as disappointing and not ambitious enough.

For this reason, six Pacific countries abstained in the vote on the NZF. While they supported the original plan for its adoption in October 2025, they have used the delay to push again for more ambition.

John Kautoke, advisor to a group of Pacific nations called 6PAC+, told Climate Home News that the NZF “cannot diminish its already inadequate ambition. If anything, the NZF must increase in ambition if we are going to renegotiate its parameters.”

Analysis by the Institute of Marine Engineering, Science and Technology (IMarEST) suggests that, of the five proposals, only Tuvalu’s would meet the 2030 and 2040 emissions reduction targets for global shipping that were agreed by governments in 2023. Those were for cuts of 20% between 2008 and 2030, 70% by 2040 and then reaching net zero “by or around, i.e. close to 2050”.

Despite this, the UK, Australia, Canada and South Africa have formally proposed that governments adopt the NZF, which won support in a 63-13 vote among governments at the April 2025 talks. Trump’s US walked out halfway through.

According to IMarEst’s analysis, while the NZF proposal will not be enough to meet the industry’s targets, it will reduce emissions more cheaply than the Pacific proposal.

A proposal by Brazil – which fought hard for the NZF last October – suggests tweaking the framework to make meeting targets easier in the short term and harder in the long term.

While this compromise will make it more appealing to the owners of polluting ships and countries that support them, IMarEst estimates it would lead to higher cumulative emissions than either the NZF or Pacific proposals.

The NZF stipulates that fees for high-polluting shipowners should be be put into a Net Zero Fund and used to promote clean shipping fuels and a fairer transition. The Brazilian proposal would delay raising and spending these funds by two years, from 2029 to 2031.

Liberia’s proposal weakens emissions cuts

The US and Saudi Arabia are likely to swing behind a new proposal from Liberia, whose government makes millions of dollars a year selling the right for shipowners to register their vessels in the small West African nation via a US-based company.

This proposal would weaken the emissions reduction targets. IMarEst says it would cut the industry’s emissions at most by a half by 2050, falling far short of the target agreed in 2023 for international shipping to reach net zero “close to 2050”.

It would also replace the NZF’s fees for missing targets with a carbon trading system. As a result, there would be no Net Zero Fund and therefore less money available to incentivise green fuels and make the transition more equitable for poorer nations.

Pacific advisor Kautoke said that, as well as preventing shipping from reaching zero emissions by 2050, Liberia’s proposal would mean the Pacific “will not receive any support to deal with the disproportionately negative impacts created by the cost of the transition”.

“We get a double blow if we adopt the Liberian proposal,” he warned. “We get all the cost of a transition without any support, and we have an industry that continues to burn fossil fuels to an unforeseen point.”

Japanese proposal favours shipowners

Japan has submitted a late proposal to amend the NZF so that shipowners have more control over how the fees they would pay for emitting above a set threshold are spent.

University College London professor Tristan Smith has argued that this change means there will be no central mechanism to incentivise investments in clean fuels. He wrote on LinkedIn that under the system put forward by Japan, shipowners would be able to select which green projects their fees would go to. They could choose their own or those of a sister company or other shipowners, rather than funding broader just transition projects that would benefit marine workers or developing countries hit by rising shipping costs.

Despite its flaws, Smith added that Japan’s proposal “could still get taken seriously by some, given how appealing it may seem to shipowners who have consistently demanded control of revenues, and given how the US and other member states have pushed back against the IMO Net Zero Fund and [greenhouse gas] pricing.”

Tacit or explicit approval?

Next week, governments are expected to make statements saying which proposals – or which aspects of proposals – they prefer. Another set of talks will be held from November 23-27 before a potentially final round from November 30-December 4.

A new framework to tackle shipping emissions could be adopted at those talks if two-thirds of countries that are present and signed up to a regulation called Marpol Annex VI – endorsed by just over 100 states – vote in favour of it, as they did in April 2025.

The US and its allies are also trying to change the rules to make the next stage more difficult. Decisions that have been adopted at IMO meetings usually take effect automatically unless a certain number of countries object within a certain time period decided by governments, a system known as tacit approval.

But the US wants that to require explicit approval instead, so that any new emissions standard would not come into force unless enough governments – representing a certain percentage of the world’s shipping fleet – actively indicate support for it.

Critics say this change would give a small number of countries with large shipping registries the power to block implementation. Liberia has the world’s biggest shipping registry, run by an American company, followed by Panama and the Republic of the Marshall Islands.

Liberia and Panama have supported the US at the talks on the Net Zero Framework. The Marshall Islands has long been one of the most vocal supporters of climate action in shipping but, with its officials and shipping registry income vulnerable to US retaliation, did not sign on to the recent Pacific proposal vowing to strengthen the NZF if it is re-opened.

Brazilian negotiator Adriana de Medeiros Gabinio warned in April that the NZF’s opponents are trying to change the rules by which it comes into force as a “safety net to block” it.

The post Battle over cleaning up shipping set to resume at London talks appeared first on Climate Home News.

Battle over cleaning up shipping set to resume at London talks

SYDNEY, Wednesday 26 August 2026 — New 2026 Sustainability Reports released by supermarket giants Coles and Woolworths this week demonstrate the retailers are failing on their commitments to end deforestation in their supply chains.

Adele Chasson, Nature Policy Lead at Greenpeace Australia Pacific said:

“These so-called sustainability reports are revealing. Despite their public commitments in 2024 and 2025, neither Coles nor Woolworths have taken deforestation-linked beef off their shelves. Meanwhile, bulldozers continue to tear up forests and bushland, pushing wildlife closer to extinction and causing mass toxic runoff to flow into the Great Barrier Reef. Millions of native animals like koalas are losing their homes to beef pastures each year, while the big supermarkets put off action.

“Australians would be shocked to know that beef on the shelves of our biggest supermarkets could be pushing threatened species to the brink of extinction. Collectively Coles and Woolworths have made more than $2 billion in profits in the last year, profiting from the destruction of wildlife and precious Australian nature. Coles and Woolworths owe it to shoppers to deliver on their promises and end deforestation in their supply chains now.

“As big beef buyers, Coles and Woolworths have an essential role to play in keeping Australia’s unique forests standing. They can help stop the Great Barrier Reef from being poisoned by runoff and protect iconic forest wildlife by taking deforestation off their shelves. It’s time these big companies put their money where their mouths are and follow through on their promise of sourcing and supplying deforestation-free beef.”

Coles, Woolworths failing on deforestation commitments