Published

2 years ago

December 19, 2023

Alice Rush

The Earth’s jet streams play a fundamental role in the speed and direction of weather systems across the world.

This means that they are crucial for understanding extreme weather events and how they will change as the world warms.

Research suggests that upper-level jet-stream winds will accelerate on average as global temperatures rise, but little is known about how their fastest winds – known as “jet streaks” – will change.

In a first-ever study, published in Nature Climate Change, my co-author and I show that fast jet-stream winds will get faster and faster — by around 2% for every degree Celsius the world warms. This means that fast winds will speed up around 2.5 times more than average jet-stream winds.

Furthermore, it means we should anticipate record-breaking jet-stream winds as warming continues.

Our research also reveals that this acceleration occurs because the difference between the density of the air in the tropics and the air at the poles will increase.

While further work will be needed to understand the full impact of our findings, we expect that they will include stronger severe storms and an increase in clear-air turbulence for aircraft passengers.

Fast flowing

The Earth’s jet streams are fast-flowing narrow bands of wind high up in the atmosphere. The fastest jet-stream winds blow from west to east and occur in the upper troposphere, around 10-12 km above the surface.

Jet streams are important because they shape Earth’s surface climate by steering weather systems, and so they can affect where severe weather occurs. For example, the regions around fast upper-level jet-stream winds – called “jet streaks” – have been linked to the occurrence of storms, tornadoes, hail and severe winds.

Jet streams are also key for air travel, providing an ideal tailwind for aircraft. Previous research has established that the average wind speed of the upper-level jet stream increases under climate change. This has the potential knock-on effect of causing more clear-air turbulence for aircraft passengers.

Our research was inspired by reports in 2019 of transatlantic flights breaking speed records. As a result, we set out to find out how climate change will affect fast jet-stream winds.

Little is known about how fast upper-level jet-stream winds – classed as those above the 99th percentile – could change as the world warms. Furthermore, no mechanism has been proposed to explain why fast jet-stream winds would change.

Fast-get-faster response

We started by examining how physics-based climate models project fast jet-stream winds would change. We used models from the sixth Coupled Model Intercomparison Project (CMIP6), which were developed for the latest assessment by the Intergovernmental Panel on Climate Change (IPCC).

In these model projections, we compare daily jet-stream winds that exceed the 99th percentile at the end of the 20th (1980-2000) and 21st (2080-2100) centuries under a very high emissions scenario (SSP5-8.5). We also compare wind speeds for the near-term in an intermediate scenario (SSP2-4.5), which is broadly in line with the trajectory of global emissions today.

Our analysis finds that climate change makes the fastest upper-level jet-stream winds get faster and faster – by about 2% for every degree Celsius the world warms. This means that fast winds will speed up around 2.5 times more than average jet-stream winds.

We refer to this as the “fast-get-faster” response and we find the effect in all seasons of the year.

You can see this in the chart below, which shows the percentage change in the fastest winds at around 12km altitude per degree of warming across different latitudes (from 80 degrees south on the left-hand side to 80 degrees north on the right).

While the fast winds increase at all latitudes, those in the “extratropics” – that is, between around 20 to 60 degrees, where jet streams are found – are the fastest to begin with and thus get the largest boost under climate change.

Percentage changes in fast (>99th percentile) winds at 200 hectopascal (hPa), normalised by the global average change in surface air temperature for each climate model from 80 degrees south to 80 degrees north in latitude. Simulations use SSP5-8.5. The black line indicates the multi-model average and the shading indicates one standard deviation of the response across all the models. Source: Shaw & Miyawaki (2023)

Moist air

In addition to quantifying the “signal” of long-term change, we also provide a physical explanation for why it occurs.

Bridging the gap between simulating the response to climate change using models and understanding the causes helps us justify that this is a signal to take seriously.

The first step we take is to simplify the model to help isolate what physics underlies the signal. When the model is run without ocean currents and without land, we still find the signal.

This suggests that the fast-get-faster signal emerges in a world formed entirely of water. The result implies that the physics of a moist atmosphere is key to explaining the fast-get-faster response.

The second step we take is to use our physical understanding of the jet stream to quantify the connection between moisture and the signal.

The jet stream exists because of the contrast of density between air at the equator, which is warm and light, and air at the pole, which is cold and dense. We connect this contrast to the response of moisture under climate change.

In particular, in today’s climate, tropical air holds more moisture than air at the poles because it is warmer. Climate change exacerbates this contrast because hotter air can hold much more moisture than colder air.

While the air at the poles is warming more rapidly than in the tropics, hotter air can hold so much more moisture than cold air that the overall density difference still increases.

This effect increases the density contrast under climate change, accelerating the jet-stream winds. Importantly, the effect is multiplicative – namely, fast jet-stream winds today that involve a steep density contrast would be boosted much more in the future than slower jet-stream winds that involve a shallower density contrast.

Thus, our results project record-breaking jet-stream winds.

Emerging signal

When we look at the recent past (1980–2022) using reanalysis data – which combines physical observations with model simulations – we do not find that the fast-get-faster signal has yet emerged from the noise of natural variability.

However, all the climate models in our study suggest that a statistically significant fast-get-faster signal will emerge for the extratropics in both the southern and northern hemispheres by the middle of this century.

Specifically, under SSP2-4.5, all climate models project the signal in the southern and northern hemispheres extratropics by 2038 and 2048, respectively. Under SSP5-8.5, this is slightly earlier – by 2035 and 2045, respectively.

This is shown in the figures below, which show the percentage change in fast jet-stream winds, relative to 1980-2000, from 1980 to 2050 in the southern (top) and northern (bottom) hemispheres, excluding the tropics. The lines indicate reanalysis data (black) and climate models projections under SSP2-4.5 (green) and SSP5-8.5 (orange).

The charts on the right-hand side show the trend, per degree of warming, for each model (green and orange) and the reanalysis data (black). Closed and open circles indicate results that are and are not statistically significant, respectively.

Timeseries of percentage changes (relative to 1980-2000) in fast 200hPa jet-stream winds in reanalysis and climate models for different emission scenarios for the southern (top) and northern (bottom) hemisphere extratropics from 1980 to 2050. Data are presented as multi-model average (thick line) with one standard deviation of the response across the models (shading). Right-hand charts show the linear trends of these changes per degree of global warming, where statistically significant trends are indicated by closed circles. Source: Shaw & Miyawaki (2023)

We are now working to better understand the knock-on impacts of these changes in the jet stream for severe weather.

New climate models are allowing scientists to look in greater detail at how extreme weather is – and will – change. Ultimately, unravelling the impacts of climate change on winds at regional scales will help society better prepare for the implications of a warming world.

The post Guest post: Why ‘jet-streak’ winds will get faster as the climate warms appeared first on Carbon Brief.

Guest post: Why ‘jet-streak’ winds will get faster as the climate warms

Climate Change

New loss and damage fund could run out of money next year

Published

5 hours ago

April 25, 2026

Alice Rush

Despite not yet paying out any money, a UN-backed fund meant to address the loss and damage caused to developing countries by climate change could face “liquidity issues” by the end of next year, its head warned today.

With ten projects already requesting $166 million in total, the fund’s Executive Director Ibrahima Cheikh Diong warned a board meeting in Zambia that the fund was likely to be “oversubscribed” and should anticipate cashflow problems.

A framing paper prepared by the fund’s secretariat similarly warns that “given the current status of the capitalization of the Fund, there is a risk of the Fund exhausting its capital by the end of 2027, which could result in a loss of operational momentum and expose the FRLD to reputational risk”.

Since governments agreed to set up the fund at UN climate talks in Egypt in 2022, wealthy nations have promised $822 million, but delivered just $449 million.

The fund is expected to approve its first projects at its next board meeting in July. Early proposals submitted include strengthening responses to floods in Bangladesh and the Nigerian city of Lagos, and improving water infrastructure in Jamaica following Hurricane Melissa last year.

A woman walks over debris, outside a store where food is being distributed, after Hurricane Melissa made landfall in Black River, Jamaica, October 30, 2025. (REUTERS/Octavio Jones )

Millions not billions

ActionAid Zambia climate justice coordinator Michael Mwansa told the board meeting that he was concerned about “the failure of the Global North governments to deliver on their climate finance obligations, making it largely impossible to scale up [the fund’s initial stage] significantly, if at all”.

“Pledges remain nowhere near the billions and even the trillions needed to address loss and damage to the Global South”, Mwansa added, highlighting reports which found that financing loss and damage could cost developing countries up to $400 billion a year.

The fund’s board discussed its strategy for raising more money at its meeting this week while climate campaigners called, in an open letter, for it to aim to secure $50 billion a year from developed countries starting next year, rising to $100 billion a year by 2031 and $400 billion by 2035.

The World Bank-hosted fund aims to have revenue-raising rounds known as replenishments every four years, with the first in 2027.

Governments have agreed to “urge” developed countries to contribute but only to “encourage” other nations to do so and the fund’s secretariat wants to appoint a “high-level champion” to lead the replenishment team.

The fundraising strategy will be discussed further at the next board meeting in the Philipines in June.

Campaigners’ open letter calls for developed countries to contribute more and for them to introduce taxes on fossil fuel companies, financial transactions, luxury air travel and wealth to raise money for the fund.

“Rich countries must be held strictly accountable for the devastation they have caused,” said Climate Action Network International head Tasneem Essop. “Their failure to fulfil their responsibility to the Loss and Damage Fund is not just an oversight; it is a shameful betrayal of humanity.”

The post New loss and damage fund could run out of money next year appeared first on Climate Home News.

New loss and damage fund could run out of money next year

Climate Change

Don’t be so reckless: Hands of Scott Reef

Published

21 hours ago

April 24, 2026

Alice Rush

Today, Greenpeace activists disrupted Woodside’s Annual General Meeting, its biggest corporate event of the year, to put the dirty gas corporation’s disastrous plans to drill at Scott Reef front and centre.

Watch and share the video

While a community rallied outside the shareholder meeting, Greenpeace activists brought the protest inside.

Together, a clear message was sent to Woodside’s executives: keep your hands off Scott Reef.

Inside, a choir of activists performed a ‘Save Scott Reef’ rendition of Angie McMahon’s cover of ‘Reckless’ – a plea to Woodside’s executives, including new CEO Liz Westcott, and shareholders to abandon their reckless plans to drill for dirty gas on the doorstep of a pristine ocean ecosystem.

Several activists were escorted out of the meeting by security while singing and holding up “Hands off Scott Reef” signs that had been smuggled into the room.

Outside, a powerful community gathered in protest, calling on WA and Federal governments to reject Woodside’s Browse project and put our oceans and climate first.

Why are we doing this?

Woodside’s Browse project involves drilling 57 gas wells underneath and around Scott Reef – a critical habitat for rare marine life including pygmy blue whales, green sea turtles and the dusky sea snake.

Share the video

Gas would be extracted and transported to the Burrup Hub – the most polluting fossil fuel project in Australia. This proposal would industrialise Australia’s largest freestanding oceanic reef system, threatening the marine life that relies on it and the climate.

This project has already been called “unacceptable” by the WA EPA, and has not yet been approved by either the WA or Federal government.

That means our voices matter, now.

Woodside cannot be trusted with our oceans. Together, we can save Scott Reef.

Don’t be so reckless: Hands of Scott Reef

Climate Change

DeBriefed 24 April 2026: Europe’s energy-crisis plan | Renewables overtake coal | Colombia’s fossil-fuel summit

Published

1 day ago

April 24, 2026

Alice Rush

Welcome to Carbon Brief’s DeBriefed.
An essential guide to the week’s key developments relating to climate change.

This week

Europe’s energy plan

ENERGY CUSHION: On Wednesday, the European Commission set out a package of measures to offset surging energy prices caused by the Iran war, reported Reuters. The draft “actions” include cutting electricity taxes and coordinating the filling of fossil-gas storage this summer, the newswire explained. It added that the package stopped short of “major market interventions”, such as capping gas prices or taxing the windfall profits of energy companies. (Carbon Brief published an interactive table of the 44 actions.)

‘BAD SCENARIO’: The newswire quoted EU energy commissioner Dan Jorgensen, who said to expect higher gas prices for a “couple of years”, adding: “We really do need to get rid of our dependency on gas as fast as possible. So, for us, this means speeding up more clean energy.” Legal proposals to change tax rules are expected in May, the article said, noting: “Tax changes require unanimous approval from EU countries, making them difficult to pass.”

FLIGHT RISK: The 16-page “AccelerateEU” document also includes plans to coordinate on jet fuel and diesel supplies “to fend off a looming shortage”, said Politico. Jorgensen told Sky News that European summer holidays were “very likely” at risk of “flight cancellations or very, very expensive tickets”. The Financial Times reported that German airline Lufthansa has already “cancelled 20,000 flights between May and October to save fuel”.

Around the world

RENEWABLES RECORD: Renewable energy overtook coal last year to become the world’s largest source of electricity, according to analysis by thinktank Ember, covered by Carbon Brief.
‘PRIORITISE UNITY’: France chose to omit climate change from the agenda of a G7 meeting in Paris this week in order to “avoid a row with the US”, said Agence France-Presse.
CHINA WARNING: China has pledged to “strictly control” coal use and will grade local authorities on how well they meet the country’s climate goals, according to two new policies covered in a Q&A by Carbon Brief.
‘DOUBLE DOWN’: The UK government said it will “move…to break [the] link between gas and electricity prices” in response to the spike in fossil-fuel prices, reported Carbon Brief.
EXTREME HEAT: A report from the UN Food and Agriculture Organization (FAO) and the World Meteorological Organization (WMO) warned that global food systems are being “pushed to the brink” by increasingly common and severe heatwaves on land and at sea, reported the Guardian.
WHAT’S IN A NAME: In a national vote, Japan selected “kokushobi” – translated as “cruelly hot” – as the new term to describe days that hit 40C, reported BBC News.

£785

The amount that a new electric vehicle is cheaper, on average, than a new petrol car, according to car sales website Autotrader. The Guardian described this as a “significant milestone in Britain’s transition away from fossil fuels”.

Latest climate research

Climate-driven extremes in temperature and pH put “underwater cultural heritage”, such as shipwrecks in the Taiwan strait, at greater risk of corrosion | Climate Services
As many as 98% of environmental claims and commitments made by meat and dairy companies over 2021-24 could be categorised as “greenwashing” | PLOS Climate
Bioenergy with carbon capture and storage (BECCS) is “unlikely to generate negative emissions within 150 years” and is “likely to increase electricity costs by ~3.5-fold” | Nature Sustainability

(For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.)

Captured

Chart showing that 2026 is on track to be the second-warmest year

With a strong – or even “super” – El Niño event expected to develop later this year, Carbon Brief estimated that 2026 is on track to be the second-warmest year on record. The prediction puts global average temperature in 2026 at between 1.37C and 1.58C above pre-industrial levels, with a best estimate of 1.47C. This means that 2024 is “virtually certain” to be one of the top-four warmest years, but there is still a 19% chance that 2026 will be the warmest year on record – beating the prior record set in 2024.

Spotlight

Countries mull fossil-fuel transition in Colombia

This week, Carbon Brief reports from a first-of-its-kind summit on transitioning away from fossil fuels being held in Santa Marta, Colombia.

Around 60 countries are arriving in Santa Marta, Colombia today where – against a backdrop of white-sand beaches, rolling forested hills and stifling humidity – they will consider ways to move away from fossil fuels.

The first global summit on transitioning away from fossil fuels comes after a large group of nations campaigned for – but, ultimately, failed – to get all countries to formally agree to a “roadmap” away from coal, oil and gas at the COP30 climate summit in Brazil last November.

The nations gathering in Santa Marta for the summit, co-hosted by Colombia and the Netherlands, call themselves the “coalition of the willing”.

Together, they account for one-third of global fossil-fuel demand and one-fifth of global production, according to the Colombian government.

The group includes major oil-and-gas producers such as the UK, Canada, Australia, Brazil and Norway. Some big emitters – such as the US, China and India – are not expected to attend. (There is a question mark over whether China and India were invited.)

Academics to advise

In a departure from COP summits, the six-day event, from 24-29 April, will begin with a “science pre-conference”, where academics from across the world will present and discuss the latest scientific evidence on ways to transition away from fossil fuels.

Ahead of this, countries attending the talks have already been handed a draft scientific report with “action recommendations”, such as “halting all new fossil-fuel expansion” and “reject[ing] gas as a bridging fuel”, as revealed by Carbon Brief.

The report will be further debated and refined by scientists attending the academic segment of the Santa Marta talks, before a final version is made public towards the end of April, Carbon Brief understands.

The science pre-conference will also separately see the launch of a new advisory panel on fossil-fuel transition and a scientifically led roadmap for how Colombia can transition away from fossil fuels, sources tell Carbon Brief.

Alongside the science pre-conference, dialogues will also be held with Indigenous peoples, environmental organisations and other stakeholders.

‘High-level segment’

The science pre-conference will be followed by a “high-level segment” from 28-29 April, where ministers and other policymakers will meet to consider ways to transition away from fossil fuels. (Colombia’s president Gustavo Petro Urrego is expected to speak.)

At the end of the conference, countries are due to release a report featuring a “menu of solutions” for transitioning away from fossil fuels, according to Colombia’s environment minister Irene Vélez Torres.

This report is, in turn, set to inform a global “roadmap” on transitioning away from fossil fuels being developed by the Brazilian COP30 presidency, which is due to be presented at COP31 in Turkey this November.

The Brazilian COP30 presidency offered to bring forward a “voluntary” fossil-fuel transition “roadmap” outside of the official COP process, after countries failed to formally agree to one during negotiations in Belém.

Watch, read, listen

‘SHADOW DOCKET’: The New York Times obtained the “secret memos” behind the US supreme court’s decision in 2016 to block the Obama administration’s clean-power plan.

EGREGIOUS ENGAGEMENT: DeSmog identified multiple social media accounts in Sri Lanka posting AI-generated “energy policy rage bait” to UK Facebook feeds (as first revealed by Carbon Brief’s Leo Hickman).

CHINA ‘DOMINANCE’: A “Bloomberg originals” video looked at the “race to challenge China’s EV lead”.

Coming up

24-29 April: First conference on transitioning away from fossil fuels, Santa Marta, Colombia
28-29 April: Innovation Zero world congress, London, UK
29 April: Stop food waste day
6-7 May:GLF Africa 2026: stewarding our rangelands, Nairobi, Kenya

Pick of the jobs

Natural England, chief executive officer | Salary: circa £130,000. Location: UK
ETH Zurich, postdoctoral position in climate science | Salary: Unknown. Location: Zurich, Switzerland
International Energy Agency, partnership manager – clean energy ministerial | Salary: €97,180. Location: Paris, France
Greenpeace, media diversification press officer | Salary: £48,396-£55,644. Location: London, UK (hybrid)
Our World In Data, writer | Salary: £80,000-£120,000. Location: Oxford, UK or remote