The UK government has slashed its hopes for electric planes and “sustainable aviation fuels” (SAFs), ahead of giving the green light to a third runway at Heathrow.
An “ambitious” rollout of new technologies and efficiency upgrades will only cut flight emissions by a quarter over the next two decades, according to forecasts quietly released in June.
This would leave aviation emissions in 2050 nearly 50% higher than expected under the “jet-zero” strategy, launched by the previous Conservative government in 2022.
The Labour government has signalled its support for a contentious third runway at Heathrow airport, with a final planning decision expected by 2029.
Ministers have justified this expansion by citing the rollout of clean-aviation technologies.
Yet, the updated forecasts suggest that rising flight numbers and a reduced role for “techno-fixes” will leave aviation emissions stubbornly high in 2050 – the UK’s legal target for net-zero.
If this is to be compatible with UK climate goals, then these higher emissions from flights in 2050 would need to be taken out of the atmosphere using costly and largely unproven “carbon dioxide removal” technologies – or by planting gigantic new forests.
Emissions up
The previous government’s “jet-zero” strategy committed the UK to a “high ambition” pathway that would have seen aviation emissions peak at 38.2m tonnes of carbon dioxide equivalent (MtCO2e) in 2019 and drop to 19.3MtCO2e in 2050.
At the time, the Conservative government said this “clear goal” was achievable, alongside airport expansion and rising flight numbers.
Its strategy relied heavily on the extensive use of early-stage technologies, such as SAFs and battery-powered planes, as well as wider fuel-efficiency improvements.
In public statements, Labour has broadly continued this approach, backing new airport runways while supporting SAFs as a way to curb aviation emissions.
However, the government’s latest forecast, quietly published ahead of the formal approval of a new runway at Heathrow, sets far lower expectations for these technologies.
Its “technology development” pathway, with “ambitious carbon abatement measures”, only sees emissions drop to 28.1MtCO2e in 2050. As the chart below shows, this is around 9MtCO2e higher than the jet-zero strategy’s stated goal – a roughly 50% increase.
The shift is down to much lower expectations for SAF uptake, fuel-efficiency improvements and the roll-out of battery-powered planes, as well as lower international carbon prices.
The government now expects SAFs to make up 30% of aviation fuel by 2050, rather than 50%. It also concedes that SAFs will save less carbon over their lifecycle than previously thought.
SAFs have faced considerable criticism, due to limited supplies and uncertainty around the extent to which they cut emissions. Even meeting the UK’s relatively modest goal of 22% SAF uptake by 2040 would require enormous – potentially unattainable – volumes of waste products, which are currently the main source of the fuel.
For its new forecasts, the government commissioned a separate analysis of likely aircraft fuel-efficiency improvements over the next few decades. This analysis, from the Aviation Impact Accelerator, yielded “less optimistic” projections than earlier work.
Fuel-efficiency improvements have therefore been revised downward from 2% per year in the “jet-zero” strategy to 1.3% in the new “technology development” scenario.
There is also a reduced role for battery-powered planes, with only some of the smallest zero-emissions aircraft expected to be in use by 2035.
Crucially, even making the more limited emissions cuts in the new “technology development” pathway would require greater efforts to decarbonise the aviation sector.
If the UK fails to implement new policies or innovations, while flight numbers continue to rise, then aviation emissions would be even higher in 2050 than they are today.
This is illustrated by the pink “current trends” pathway in the chart above, in which emissions increase to 41.1MtCO2e by 2050.
This is roughly double the amount targeted by the jet-zero strategy and recommended by government climate advisors, the Climate Change Committee (CCC).
Budget ‘busting’
The new forecasts all account for the growth of several UK airports, including “planned Heathrow expansion”. Overall, passenger numbers would be at least 50% higher by 2050.
In contrast, the CCC and other experts have advised that the rise in passenger numbers may need to be limited, in order to keep emissions down.
In order to meet the UK’s net-zero target, any aviation emissions that remain in 2050 would need to be offset by planting many thousands of hectares of new forest, or by relying on costly and largely unproven CO2 removal technologies.
Tim Johnson, director at the Aviation Environment Federation (AEF), says the new forecasts present “a more honest and realistic vision of what’s possible in the next 24 years”. However, he tells Carbon Brief:
“Less reliance on cleaner technology and fuels reopens the debate about the role and scale of greenhouse gas removals and ways to tackle the projected 50% growth in demand for air travel.”
AEF calculations, based on government data and shared with Carbon Brief, suggest that emissions from the third runway at Heathrow would initially be relatively modest, reaching 3.5MtCO2e per year in 2050. Its emissions would then be expected to rise significantly beyond the legal 2050 net-zero deadline.
Previously, the Labour government has explicitly cited SAFs and other new technologies as part of its justification for expanding Heathrow airport.
Dr Lois Pennington, a research associate at the University of Manchester who has analysed Heathrow’s emissions impact, says the government’s new forecast shows “we are projected to be well over aviation’s share of the carbon budget even before a third runway is considered”.
She tells Carbon Brief:
“For Heathrow, it means expansion can no longer be waved through on the promise of technology, and any approvals will be in the full knowledge that it will bust our legally binding carbon budgets.”
The post UK aviation emissions to be 50% higher than thought by 2050, government admits appeared first on Carbon Brief.
UK aviation emissions to be 50% higher than thought by 2050, government admits
Extreme heat is one of the deadliest climate hazards, but no two heatwaves are the same.
Heat extremes that happen outside of the peak summer months are often more dangerous because they can catch people off guard.
Heatwaves that hit during the spring or the first heatwave of the summer are riskier because people’s bodies are not yet accustomed to the heat and cooling strategies, such as air conditioning or public cooling centres, might not be available.
On the other hand, heatwaves that happen in the autumn, after a long summer season of heat exposure, can place further strain on bodies and local infrastructure that are already under stress.
As the climate changes and global temperatures rise, research has shown that heatwaves are becoming more frequent, intense and lengthy.
Our study, published in AGU Advances, is the first to measure whether the timing of extreme heat during the calendar year is changing around the world.
We find that, in more than half of the world, extreme heat events are spreading into the “shoulder seasons”, but doing so unevenly – in other words, they tend to creep more into autumn or spring, depending on the location.
Defining heat seasons
Meteorological summer is often assumed to be the warmest three-month period of the year. It is simplistically defined as June to August in the northern hemisphere and December to February in the southern hemisphere.
However, extreme heat seasons vary from place to place and do not always neatly map on to these defined periods.
Our study, therefore, goes beyond traditional definitions of seasons and instead focuses on “local heat seasons”. We define these as the three consecutive months when extreme heat events happened most often in the 1980s.
From this starting point, our research looks at how extreme heat is creeping into the two-month periods before and after a local heat season. We call these periods “shoulder seasons”.
This flexible definition of heat and shoulder seasons allows us to measure how the timing of extreme heat has changed over time.
Specifically, we look at the percent of annual heat days that occurred in the heat season and shoulder seasons at each location on Earth and measure how those relative shares have shifted over the last 45 years.
For our analysis, we use climate data from 1980-2024 from the MERRA2 reanalysis dataset. To ensure our results were robust, we repeated the process using ERA5 reanalysis data.
We picked the 1980s as our baseline decade as it was the start of the common time period between the two reanalysis datasets. We compared this to climate data in the decade between 2015-24.
Comparing these two time periods – the opposite ends of our datasets – allowed us to register a larger magnitude change and account for cumulative effects of climate change.
We consider measures of both dry and humid heat, as each has distinct impacts. Dry heat tends to be more dangerous to plant and ecosystem health, while humid heat is more strenuous for humans.
We use the dry-bulb temperature and wet-bulb globe temperature as our measures of dry and humid heat, respectively.
Created in the 1950s by the US military, wet-bulb globe temperature has a long history as an international standard used for outdoor sports and occupational hazard monitoring. It combines measurements of temperature, humidity, wind speed and solar radiation.
Changing heat seasons
Our research finds that, in the 1980s, extreme heat around the world was closely confined to a single heat season. For example, some 93% of the world’s land area experienced more than 80% of extreme dry-heat days during its traditional dry-heat season.
Surprisingly, this was even true in the tropics, where there is much less of a seasonal swing in temperatures.
We also show that extreme dry- and humid-heat seasons are often different from one another, typically offset by one month. This is especially true in places influenced by monsoon systems, such as north-western Mexico and central India, where the extreme dry-heat season precedes the extreme humid-heat season.
But, the edges of these extreme heat seasons are starting to blur.
Extreme heat events are spreading out significantly in the calendar year in more than half of global land areas.
This extension of the extreme dry- and humid-heat seasons means that dangerous heat has started to creep into the shoulder seasons – but not equally so.
The maps below show how, in western Europe, southern Africa and north-western India, a larger fraction of each year’s extreme heat events are happening in the months before the historical dry- and humid-heat seasons. These regions are shaded in green.
On the other hand, in much of the US, eastern China, northern Africa and eastern Europe, extreme heat events are increasing in frequency in the months after the traditional heat seasons. These regions are shaded in purple.
Boosting existing seasons
It is possible that these observed changes have a straightforward – and somewhat simple – explanation.
In many regions, one shoulder season – spring or autumn – is warmer than the other. One hypothesis we explored was whether a simple step up in daily heat across the calendar year makes it more likely for extreme heat days to occur in one shoulder season over the other.
Our research shows that things are not so simple.
To investigate, we created a new, “synthetic” timeseries in order to identify the impact of annual average warming. To do this, we took the baseline 1980s timeseries and “shifted up” the data by the average change in local dry or humid heat between the first and last 10 years of our dataset (1980-89 compared to 2015-24).
We find that, in most locations, intensifying the baseline seasonality in a given location by warming evenly over the course of the year explains the changes in extreme heat timing within the traditional heat season.
However, annual average warming alone cannot explain the uneven changes in how extreme heat is occurring in the shoulder seasons.
As such, we conclude there must be other factors at play.
Long-term changes in seasonal precipitation and soil moisture – whether drying or moistening – could be contributing.
There could also be potential links to land-use changes, such as agricultural intensification or increased irrigation. Natural fluctuations in regional climates, caused by phenomena such as the Pacific Decadal Oscillation and Atlantic Multidecadal Oscillation, could also be playing an important role.
To tease out the contributions of each of these drivers, scientists will need to conduct more regionally-focused studies.
Managing hazards
The expansion of extreme heat events into the shoulder seasons indicates that key protections, such as heat early warning systems and the establishment of cooling centres, may be needed outside the traditional summer months.
Further research is also required to look into whether the overlap of extreme heat with other seasonal hazards is increasing.
For example, we find that, throughout much of the US, there is a larger expansion of the heat season into the autumn than the spring. In the western US, extreme heat which stretches later into the year could increase the overlap between the extreme heat and wildfire seasons.
Meanwhile, a similar extension of the heat season into the autumn in the eastern US could increase the overlap between the extreme heat and Atlantic hurricane seasons.
Understanding how the intersection of these seasonal hazards is changing is essential for developing targeted climate adaptation strategies, given that multiple hazards happening at once or in quick succession are much more dangerous than when they happen in isolation.
Ivanovich, C. et al. (2026) Extreme dry- and humid-heat seasons are changing asymmetrically, AGU Advances, doi:10.1029/2026AV002516
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The post Guest post: How extreme heat is ‘creeping’ from summer into autumn and spring appeared first on Carbon Brief.
Guest post: How extreme heat is ‘creeping’ from summer into autumn and spring
PERTH, Thursday 10 September 2026 — In response to the announcement of draft federal domestic gas reservation legislation, the following comments can be attributed to WA Campaign Lead at Greenpeace Australia Pacific, Geoff Bice:
“The gas industry has been getting away with daylight robbery in WA for years, and if the federal domestic reservation requirements are not made to apply here it is a major missed opportunity to rein them in.
“In WA, Woodside has supplied just 3.4% of the gas extracted from Australian waters and processed at its Pluto facility, flouting the expected 15% and pocketing the profits.
“If the Federal Government is not going to keep Woodside and the WA gas industry accountable, it is incumbent on the WA Government to tighten its rules.
“The WA Government needs to get a fair deal for West Australians and rule out risking pristine environments like Scott Reef and the Kimberley for unnecessary gas expansion.
“71% of Perth voters, including a majority of One Nation and Labor supporters, do not support drilling for gas at Scott Reef or fracking the Kimberley.
“Most Perth voters want a renewable energy target and a strong domestic gas reservation policy, not a run-away fossil fuel extraction and export industry.”
-ENDS-
Notes:
Greenpeace commissioned polling of voters in the Perth metropolitan area in July 2026.
Media contact
Emma Sangalli on 0431 513 465 or emma.sangalli@greenpeace.org
High res images and footage of Scott Reef can be found here
Climate Change
Foreign minister: Nepal needs “meaningful” international support to face climate threats
In the wake of the recent flash flood that swept down from the Himalayas, Nepal is seeking immediate aid from a UN fund for climate loss and damage to help vulnerable families displaced by the disaster and rebuild destroyed schools and hospitals, the country’s foreign minister told Climate Home News.
“This is exactly the kind of climate-driven catastrophe the Fund was created to address,” Shisir Khanal said in an interview. He added that “stronger global solidarity and meaningful international support” are needed for countries like Nepal, which are facing increasingly severe climate-related disasters.
The floods were caused by a glacier collapsing and triggering a landslide that forced a torrent of water and debris to rush down the Bhote Koshi River valley, causing catastrophic impacts downstream. More than 1,300 people died and over 5,300 are still missing in the area.
Khanal described the disaster as a “Himalayan tsunami”, telling Climate Home News that early assessments suggest the roads, bridges, hydropower stations, highways and settlements it wiped out could require billions of dollars to rebuild. Reconstruction estimates by the government range between $2.5 billion and $5 billion.
The minister of foreign affairs said Nepal would not be asking the UN’s new Fund for Responding to Loss and Damage (FRLD) “to write a single check for this total amount”, explaining that the government is finalising a post-disaster assessment “to guide our broader international donor appeals”.
Nepal disaster seen as test case for fledgling fund
In reality, if Nepal does receive rapid support from the FRLD, it is likely to be a fraction of the total bill because the fund has a cap of $20 million per project and has little more than $350 million available to hand out in its initial phase.
So far its board has not approved any projects as it is still working out how to allocate its scarce resources, nor does it have a process in place to respond to sudden climate disasters such as glacial lake outburst floods or powerful storms.
On August 31, Nepal’s government sent a direct appeal for emergency grant funding to the FRLD, emphasising that “a prompt response would… demonstrate that the fund can translate international solidarity into timely support for vulnerable countries and communities when it is most urgently needed”.
A couple of days later, eight developing-country board members – later joined by those from small island states – signed a letter, seen by Climate Home News, asking the fund’s board to hold an extraordinary meeting to respond to Nepal’s request.
The FRLD said in a statement that the devastating impacts on the ground “underscore both the urgency and scale of need and reaffirm the fundamental purpose for which the FRLD was established”.
It added that it is “committed to approaching Nepal’s request with the urgency, compassion, and careful consideration that these difficult circumstances require, while respecting the Fund’s governing instrument and established decision-making processes”. As of Wednesday, Climate Home News understands that discussions were still ongoing.
Designing infrastructure for extreme shocks
Khanal pointed to “the unprecedented scale” of the huge flood which occurred within a matter of minutes and swept away river gauges meant to provide early warning in Rasuwa and Nuwakot, near the border with Tibet.
“You cannot easily ‘plan’ against a mountain collapsing,” he said. But the lesson, he added in written responses in English, is that “our historical baseline for infrastructure engineering is no longer sufficient”.
Building resilient infrastructure means that “hydropower projects, roads and early warning systems must be designed for extreme, unpredictable climate shocks”, he said. Another key element will be plans to better understand and protect ecosystems, he added.
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The minister noted that Nepal, India and China share a common, interconnected Himalayan ecosystem and all three countries are affected by the impacts of climate change in the Himalayan mountain chain.
“Therefore, our call is for the three countries to work together to strengthen preparedness, resilience and regional cooperation,” he said.
New research from consultancy Systemiq, released on Wednesday, finds that Himalayan glaciers are losing mass 65% faster than a decade ago, and that only around 20 of the Himalaya’s estimated 40,000 glaciers are currently monitored. India alone has 56 glacial lakes rated very high risk, it warns.
Early cross-border efforts on information-sharing
Since the same region of Nepal was hit by smaller-scale but still highly destructive flooding in 2024 and 2025, China and Nepal have stepped up efforts to cooperate in tackling glacier-related risks in the region.
In August 2025, Climate Home News reported that authorities in both countries had agreed to share cross-border information about the risks of glacial lake outburst floods across the Tibetan region, in a first step that could be expanded to the national level in an effort to reduce deaths and damage.
This May, a delegation from China’s Ministry of Water Resources and the Water Resources Department of the Xinjiang Autonomous Region held talks with Nepalese officials in charge of water and disaster management about establishing a joint disaster information mechanism.
Then in August, a team from the Institute of Mountain Hazards and Environment under the Chinese Academy of Sciences also visited Nepal for scientific research and exchange, sharing China’s experience in monitoring glacial lakes.
Nepal and China agree to cooperate on glacial lake flooding, as warming hikes threat
However, experts told Climate Home News that progress on putting in place concrete measures has been slow. Narendra Khanal, a professor in the department of geography at Tribhuvan University, blamed that partly on Nepal’s traditional administrative system and bureaucratic delays.
“We have to share information with them, and they have to share information with us,” he said. “In my understanding, the Chinese side is also facing difficulties in making this cooperation work.”
Mohan Bahadur Chand, a Himalayan glaciologist and assistant professor at Kathmandu University, said China has the technology and human resources to provide significant information to its neighbour downstream.
But, to make that work, “we have to build trust between the two countries”, which is currently lacking but could be developed, he said. “As scientists, we are already working with them personally. If we create a trusted environment, cooperation should not be difficult.”
Nepal lacks monitoring and warning technology
Experts said Nepal – one of the world’s least-developed countries – does not have the technology or resources to install the sophisticated monitoring and warning systems needed to protect its population from growing threats linked to accelerating glacier melt in the Himalayas.
A senior meteorologist at the Department of Hydrology and Meteorology, who did not want to be named, told Climate Home News that the government had not invested enough in rainfall and weather monitoring stations, especially above 3,500 metres, and therefore lacks reliable data about what is happening at high altitudes.
“The stations we have are operated by different organisations, but many of them are not functioning properly,” the official added.
Comment: The loss and damage fund needs far more finance to deliver climate justice
This year, the UN’s Green Climate Fund released initial funding for a $50-million project to address the risks from four glacial lakes in other parts of Nepal, but has come under criticism for taking seven years to approve the proposal. The fund said this was due to efforts needed to strengthen and consult on the project, as well as administrative, institutional and COVID-related delays.
Foreign minister Khanal said Nepal was calling on the international community for support to tackle global warming impacts into the future.
“This disaster should not be viewed simply as a one-time event requiring one-time assistance,” he emphasised. “We need to recognise the longer-term consequences of rising temperatures and climate change, particularly for vulnerable communities and developing countries.”
The post Foreign minister: Nepal needs “meaningful” international support to face climate threats appeared first on Climate Home News.
Foreign minister: Nepal needs “meaningful” international support to face climate threats
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