‘We were trapped like rats’: Spain’s floods bring devastation and despair

 

Pedestrians look at piled-up cars in Sedavi, south of Valencia city, after deadly floods. Photograph: José Jordan/AFP/Getty Images

 Residents describe impact of floods and downpours – with some places hit with a year’s worth of rain in just eight hours

The gratitude that greeted Tuesday’s dawn downpours was short-lived in Utiel. When the longed-for rains finally reached the town in the drought-stricken eastern Spanish region of Valencia, they were merciless in their abundance.

“People were very happy at first because they’d been praying for rain as their lands needed water,” said Remedios, who owns a bar in Utiel. “But by 12 o’clock, this storm had really hit and we were all pretty terrified.”

Trapped in the bar, she and a handful of her customers could only sit and watch as Spain’s worst flooding in almost 30 years caused the Magro River to overflow its banks, trapping some residents in their homes and sending cars and rubbish bins surging through the streets on muddy flood waters.

Damaged cars lie amid debris along damaged rail lines in the flood-hit city of Valencia. Photograph: Manuel Bruque/EPA

 

“The rising waters brought mud and stones with them and they were so strong that they broke the surface of the road,” said Remedios, who gave only her first name.

“The tunnel that leads into the town was half-full of mud, trees were down and there were cars and rubbish containers rolling down the streets. My outside terrace has been destroyed – the chairs and shades were all swept away. It’s just a disaster.”

By Wednesday afternoon, the death toll in Valencia and the neighbouring regions of Castilla-La Mancha and Andalucía stood at 95 . Utiel’s mayor, Ricardo Gabaldón, told Las Provincias newspaper that some of the town’s residents had not survived the floods, but was unable to provide an exact number.

Hours earlier, Gabaldón had told Spain’s national broadcaster, RTVE, that Tuesday had been the worst day of his life. “We were trapped like rats,” he said. “Cars and rubbish containers were flowing down the streets. The water was rising to 3 metres.”

 People in the town fear some of the dead may have been older people who were unable to escape the flood waters. Remedios said: “Anyone who could get to higher ground did, but there were some old people who couldn’t even open their front doors and they were trapped there inside their own houses.”

 

Residents of La Torre, on the outskirts of Valencia city, were confronted by similar scenes on Wednesday morning.

“The neighbourhood is destroyed, all the cars are on top of each other, it’s literally smashed up,” Christian Viena, a bar-owner in the area, told the Associated Press by phone. “Everything’s a total wreck, everything is ready to be thrown away. The mud is almost 30cm deep.”

A man carries a dog in Letur, Albacete province, after flash floods hit the region. Photograph: Mateo Villalba Sanchez/Getty Images

Spain’s meteorological office, Aemet, said that more than 300 litres of rain per square metre (30cm) had fallen in the area between Utiel and the town of Chiva, 20 miles (50km) away, on Tuesday. In Chiva, it noted, almost an entire year’s worth of rain had fallen in just eight hours.

The ferocious rains have come as Spain continues to experience a punishing drought. Last year, the government approved an unprecedented €2.2bn (£1.9bn) plan to help farmers and consumers cope with the enduring lack of rain amid warnings that the climate would only get worse, and more unpredictable, in the future.

“Spain is a country that is used to periods of drought but there’s no doubt that, as a consequence of the climate change we’re experiencing, we’re seeing far more frequent and intense events and phenomena,” the environment minister, Teresa Ribera, said.

As Wednesday wore on, a distressing picture of the human and economic damage began to emerge. Spain declared three days of national mourning.

 

The prime minister, Pedro Sánchez, said the entire country felt the pain of those who had lost their loved ones, and urged people to take every possible precaution as the torrential rains moved to the north-east of the country.

The defence minister, Margarita Robles, said 1,000 members of the military emergencies unit had been deployed to help regional emergency services. In a sign that more bodies could be trapped in the mud and in houses, she also offered mobile morgues.

One man used a phone call to RTVE to plead for any news of his son, Leonardo Enrique Rivera, who had gone missing in his Fiat van after going to work as a delivery driver in the Valencian town of Riba-roja on Tuesday.

A man picks his way through debris in Letur. Photograph: Susana Vera/Reuters
 

“I haven’t heard from him since 6.55 yesterday,” said Leonardo Enrique. “It was raining heavily and then I got a message saying the van was flooding and that he’d been hit by another vehicle. That was the last I heard.”

Esther Gómez, a town councillor in Riba-roja, said workers had been stuck overnight in an industrial estate “without a chance of rescuing them” as streams overflowed. “It had been a long time since this happened and we’re scared,” she told Agence France-Presse.

As the search for the dead continued, experts warned that the torrential rains and subsequent floods were further proof of the realities of the climate emergency.

“No doubt about it, these explosive downpours were intensified by climate change,” said Dr Friederike Otto, leader of world weather attribution at the Centre for Environmental Policy, Imperial College London.

“With every fraction of a degree of fossil fuel warming, the atmosphere can hold more moisture, leading to heavier bursts of rainfall. These deadly floods are yet another reminder of how dangerous climate change has already become at just 1.3C of warming. But last week the UN warned that we are on track to experience up to 3.1C of warming by the end of the century.”

There were similar, if differently expressed, sentiments in Utiel on Wednesday. “There was one guy here with me yesterday who’s 73, and he said he’d never seen anything like this in all his years,” said Remedios. “Never.”

 

Tempestades na Espanha deixam mais de 62 mortos

 

Região de Málaga também foi atingida

 

Autoridades da Espanha confirmaram nesta quarta-feira (30/01) que ao menos 62 pessoas morreram e várias estão desaparecidas após as enchentes  que atingiram a província de Valência. As inundações arrastaram carros, transformaram ruas de vilarejos em rios e interromperam o tráfego em linhas ferroviárias e rodovias.

Nesta terça-feira, chuvas torrenciais e inundações causaram estragos em várias partes do país, principalmente em uma ampla área do sul e do leste. Os maiores impactos foram registrados nas regiões costeiras mediterrâneas da Andaluzia, Múrcia e Valência.

Além das fortes chuvas, houve também queda de granizo e fortes rajadas de vento, segundo com o serviço meteorológico nacional Aemet. A agência previu que as tempestades devem continuar até esta quinta-feira

A força da água arrastou veículos e destroços pelas ruas de várias localidades. A polícia e os serviços de resgate usaram helicópteros para retirar pessoas de casas e carros. O governo da região de Valência pediu aos moradores que se desloquem para terrenos mais altos.

Inundações na Espanha transformaram ruas de vilarejos em rios e interromperam o tráfego em linhas ferroviárias e rodoviasFoto: JOSE JORDAN/AFP/Getty Images

 
 O transporte aéreo e ferroviário também foi afetado. Um trem de alta velocidade com quase 291 pessoas a bordo descarrilou perto de Málaga devido a um deslizamento de terra. A empresa ferroviária estatal Renfe informou que o acidente, porém, não deixou feridos.

 

Governo cria comitê de crise

O serviço de trens de alta velocidade e outras linhas de passageiros entre Valência e Madri foi interrompido. Aulas tiveram de ser canceladas em várias escolas e universidades. Mais de mil membros dos serviços de emergências da Espanha foram enviados para as áreas atingidas.

A tempestade já havia atingido Mallorca e outras Ilhas Baleares na segunda-feira, onde um alerta amarelo de tempestade ainda está em vigor para algumas áreas.

O governo da Espanha criou um comitê de crise para coordenar os esforços de resgate, que será presidido pelo primeiro-ministro, Pedro Sánchez.

Carros foram arrastados pela força das águas

 

A tempestade deve se mover para nordeste do país nesta quarta-feira, enquanto um alerta de clima severo permanece em vigor para uma grande parte da Espanha.

Tempestades após fortes secas

As tempestades que atingem a Espanha ocorrem após uma seca severa. Cientistas afirmam que o aumento dos episódios de clima extremo provavelmente está associado às mudanças climáticas. À medida que as temperaturas globais aumentam, o ar mais quente retém mais umidade, o que intensifica os níveis de precipitação.

Atividades humanas, como desenvolvimento urbano, desmatamento e infraestruturas inadequadas, também contribuem significativamente para os riscos de inundações.

rc/cn (AP, DPA, EFE)

 

Mount Fuji snowless for longest time on record after sweltering Japan summer

 

Mount Fuji on 10 August 2024. The Japanese mountain has experienced the longest time on record without snow. Photograph: Newscom/Alamy

 

 As of 29 October, the iconic mountain was still without snow, marking the longest period since records began 130 years ago.

 

Japan’s Mount Fuji remained snowless on Tuesday, marking the latest date that its slopes have been bare since records began 130 years ago, the country’s weather agency said.

The volcano’s snowcap begins forming on 2 October on average, and last year snow was first detected there on 5 October.

 

But because of warm weather, this year no snowfall had yet been observed on Japan’s highest mountain, said Yutaka Katsuta, a forecaster at Kofu Local Meteorological Office.

 

That marked the latest date since comparative data became available in 1894, he said, beating the previous record of 26 October – which had been recorded twice, in 1955 and 2016.

“Temperatures were high this summer, and these high temperatures continued into September, deterring cold air” which brings snow, Katsuta told the AFP news agency.

He said climate change might have a degree of impact on the delay in the snowcap’s formation.

The summit of Mt Fuji in Japan. Photograph: Newscom/Alamy

 

Japan’s summer this year was the joint hottest on record – equalling the level seen in 2023 – as extreme heatwaves fuelled by climate change engulfed many parts of the globe.

Mount Fuji is covered in snow for most of the year, but during the July-September hiking season more than 220,000 visitors trudge up its steep, rocky slopes. Many climb through the night to see the sunrise from the 3,776-metre summit.

Fewer climbers tackled Mount Fuji this year, however, after Japanese authorities introduced an entry fee and a daily cap on numbers to fight overtourism.

The symmetrical mountain has been immortalised in countless artworks, including Hokusai’s “Great Wave”.

It last erupted about 300 years ago.

 

Climate crisis caused half of European heat deaths in 2022, says study

 

People cooling down in the fountains of the Trocadero gardens in Paris as Europe experienced an unusually extreme heatwave in 2022. Photograph: Christophe Ena/AP

 Researchers found 38,000 fewer people – 10 times number of murders – would have died if atmosphere was not clogged with greenhouse pollutants

 

Climate breakdown caused more than half of the 68,000 heat deaths during the scorching European summer of 2022, a study has found.

Researchers from the Barcelona Institute for Global Health (ISGlobal) found 38,000 fewer people would have died from heat if humans had not clogged the atmosphere with pollutants that act like a greenhouse and bake the planet. The death toll is about 10 times greater than the number of people murdered in Europe that year.

“Many see climate change as a future concern,” said the lead author, Thessa Beck. “Yet our findings underscore that it is already a pressing issue.”

The warm weather killed more women than men, more southern Europeans than northern Europeans, and more older people than younger people. Scientists already knew carbon pollution had made the heatwaves hotter but did not know how much it had driven up the death toll.

 

They found 56% of the heat-related deaths could have been avoided if the world had not been warmed by burning fossil fuels and the destruction of nature. The share varied between 44% and 54% in the six years prior.

Even small increases in temperatures can have devastating impacts on public health, said Emily Theokritoff, a researcher at Imperial College London who was not involved in the study. “This result makes sense – heat-related death increases rapidly as temperatures push past the limits people are acclimatised to.”

 

Europe is warming twice as fast as the rest of the planet but doctors warn its hospitals are not prepared to deal with the consequences. The rise in temperatures forces more people to endure searing summer heat that pushes their bodies into overdrive even as it cuts exposure to chilling winter cold that leaves them too weak to fight off illness.

Scientists project the lives lost to hotter summers in Europe will outstrip those saved by cooler winters if the planet heats more than 2C above preindustrial levels. Last week, the UN environment programme warned the world is on track to heat by 3C by the end of the century.

The dangers of extreme heat are even greater in Africa, Asia, and South America, but a lack of data had limited studies on how it affects human health, said Beck.“A common misconception is that only extreme temperatures pose a serious risk,” she said. “However, our study, along with previous research, shows that even moderate heat can lead to heat-related deaths, particularly among more vulnerable populations.”

 

Scientists had previously used heat and health data for 35 European countries to estimate how many more people die as a result of hot weather. In the new study, they ran the model with temperatures for a hypothetical world in which humans had not heated the planet.

They found climate change was behind 22,501 heat deaths in women and 14,026 heat deaths in men.

Garyfallos Konstantinoudis, a researcher at Imperial College London, who was not involved in the study, said the authors may have overestimated the effect of heat on mortality because they did not account for how people had adapted.

He said: “Previous studies have reported a decrease in heat-mortality impact over time, due to factors including infrastructural changes and improved health care.”

To stay safe in the heat, doctors recommend drinking water, staying indoors during the hottest parts of the day and looking after older neighbours and relatives who live alone. Governments can save lives by creating action plans for hot weather, designing cities with more green space and less concrete, and cutting pollution.

“Heat can be very dangerous for the heart, especially for older people,” said Beck.

 

US power grid added battery equivalent of 20 nuclear reactors in past four years

An electricity pylon beyond a tree burned by a wildfire, in Los Angeles, California, on 28 January 2021. Photograph: Lucy Nicholson/Reuters

 

Pace of growth helps maintain renewable energy when weather conditions interfere with wind and solar

Faced with worsening climate-driven disasters and an electricity grid increasingly supplied by intermittent renewables, the US is rapidly installing huge batteries that are already starting to help prevent power blackouts.

From barely anything just a few years ago, the US is now adding utility-scale batteries at a dizzying pace, having installed more than 20 gigawatts of battery capacity to the electric grid, with 5GW of this occurring just in the first seven months of this year, according to the federal Energy Information Administration (EIA).

This means that battery storage equivalent to the output of 20 nuclear reactors has been bolted on to America’s electric grids in barely four years, with the EIA predicting this capacity could double again to 40GW by 2025 if further planned expansions occur.

California and Texas, which both saw all-time highs in battery-discharged grid power this month, are leading the way in this growth, with hulking batteries helping manage the large amount of clean yet intermittent solar and wind energy these states have added in recent years.

The explosion in battery deployment even helped keep the lights on in California this summer, when in previous years the state has seen electricity rationing or blackouts during intense heatwaves that see air conditioning use soar and power lines topple due to wildfires. “We can leverage that stored energy and dispatch it when we need it,” Patti Poppe, chief executive of PG&E, California’s largest utility, said last month.

“It’s been extraordinary growth,” said John Moura, director of reliability assessment and performance analysis at the North American Electric Reliability Corporation.

“It’s still technology that we are getting used to working with because the system wasn’t designed for it, but from a reliability perspective it presents a golden opportunity. This changes the whole paradigm of producing electricity, delivering it and consuming it. Storage gives us a bit of a time machine to deliver it when we need it.”

While scientists are clear that the US, and the rest of the world, must radically slash planet-heating emissions from electricity generation and other sources, the rapid growth of clean energy such as solar and wind provides more peaks and troughs of production that need to be actively managed to retain a reliable grid.“Batteries can smooth out some of that variability from those times when the wind isn’t blowing or the sun isn’t shining. The Germans have a word for this sort of drought: Dunkelflaute,” said Moura. “So if you have a four-hour storage battery, that can get you through a Dunkelflaute.”

Energy storage containers with lithium ion batteries at the University of California, San Diego, on 16 September 2022 in La Jolla, California. Photograph: Sandy Huffaker/AFP/Getty Images

 

Of course, wind and sun droughts can last longer than the longest-duration batteries currently available, meaning they are not a panacea. A fully clean grid will also require a vast upgrade in US transmission lines – for example, to shift renewable energy swiftly across the country to where it is needed. The permitting reform to allow this is a bitterly contested issue, with many environmental groups opposed to looser regulations they say will only empower fossil fuel concerns.

But batteries should be able to play an increasingly strong supporting role to the energy transition, with the International Energy Agency last week calling them “a key source of dispatchable capacity globally”. The IEA forecasts that batteries will provide about 40% of all short-term electricity flexibility needs worldwide by 2050.

“There are a lot of changes happening but monstrous action is still needed if we are going to make this energy transition,” said Moura.

 

 

Urban green spaces have vital role in cutting heat-related deaths, study finds

 

Abundant green space in urban areas is linked to lower rates of heat-related illness and deaths, as well as better mental health and wellbeing. Photograph: Peter Eastland/Alamy

 

Green spaces in cities play a vital role in reducing illness and deaths caused by climate breakdown, according to the most comprehensive study of its kind.

The findings of the review suggest that adding more parks, trees and greenery to urban areas could help countries tackle heat-related harms and improve public health.

The record for the world’s hottest day tumbled twice in one week earlier this year when the global average surface air temperature reached 17.15C (62.87F) breaking the record of 17.09C set days earlier.

The climate crisis is driving up global temperatures as greenhouse gas emissions released when humans burn fossil fuels warm the Earth’s atmosphere.

 

The overall beneficial effects of green spaces is well established, but until now their effects on heat-related health risks were poorly understood.

Now a review of the evidence led by the London School of Hygiene & Tropical Medicine suggests that abundant green space in urban areas is linked to lower rates of heat-related illness and deaths, as well as better mental health and wellbeing.

“Urban green spaces play a vital role in mitigating heat-related health risks, offering a potential strategy for urban planning to address climate change and enhance public health,” the researchers wrote in the journal BMJ Open.

“A review of urban greenery and its effect on heat-related morbidity and mortality suggests that urban green spaces, such as parks and trees, can have a positive impact on reducing the negative health effects associated with high temperatures,” they added.

“Studies have found that areas with more green space have lower rates of heat-related morbidity and mortality compared with areas with less green space. Moreover, urban greenery can also have a positive impact on mental health and wellbeing, which can also contribute to reducing the negative health effects of high temperatures.”

In recognition of the harmful heat-related effects of climate breakdown, one of the UN’s sustainable development targets stipulates the provision of universal access to safe and accessible green and public spaces, especially for vulnerable groups, such as children, elderly people, and those living with long-term conditions, by 2030.

For the review, researchers looked at the effects of green zones on death and ill health in urban areas across the globe, drawing on relevant published research.

They included content published in English between January 2000 and December 2022, and reviewed 12 studies out of an initial haul of more than 3,000 from Hong Kong, Australia, Vietnam, the US, South Korea, Portugal and Japan.

 

These included epidemiological, modelling, and simulation studies, as well as experimental research and quantitative analyses.

The review showed that urban green spaces such as parks and trees could help offset the adverse health effects of high temperatures. Areas with more green space had lower rates of heat-related ill health and death than areas with less green space, particularly among vulnerable groups.

Access to green spaces is an example of health inequalities facing people worldwide.

A Guardian investigation revealed earlier this year that children at the top 250 private schools in England had more than 10 times as much green space as those who go to state schools.

Doctors also warned that a “truly alarming” lack of access to green space for some families was exacerbating the child obesity crisis.

 

The Morning: America’s flooding problem

 

Good morning. Today, my colleague Christopher Flavelle writes about how people are coping with increasing floods. We’re also covering early voting, sickle cell gene therapy and Hanoi, Vietnam. —David Leonhardt

In Plant City, Fla. Caitlin Ochs for The New York Times

 

 

Three views of the water

By Christopher Flavelle  I write about how we try to adapt to climate change.

 America has a flooding problem. When Hurricane Milton hit Florida, the images of inundation seemed shocking — but also weirdly normal: For what felt like the umpteenth time this year, entire communities were underwater. Since the 1990s, the cost of flood damage has roughly doubled each decade, according to one estimate. The federal government issued two disaster declarations for floods in 2000. So far this year, it has issued 66.

The reasons are no mystery. Global warming is making storms more severe because warmer air holds more water. At the same time, more Americans are moving to the coast and other flood-prone areas.

Those conflicting trends are forcing people to adapt. Advances in design, science and engineering — combined with a willingness to spend vast amounts of money — have allowed the United States and other wealthy countries to try new ideas for coping with water. In today’s newsletter, I’ll tell you about the three basic ways to deal with flooding.

1. Fight the water

The first strategy is to fight the water: Build walls to keep it out of your city, along with giant pumps and drains to remove whatever water gets in. Think of Holland, much of which would be underwater without a massive network of barriers, or Venice, which now relies on sea walls during high tide.

But thanks to climate change, this approach means ever-more-epic fortifications. After Hurricane Katrina, the federal government built a $14 billion, 350-mile defensive ring around New Orleans. The United States is also looking at building 12 movable sea barriers to protect New York Harbor from a storm surge, at an initial cost of $52 billion.

Even the beneficiaries aren’t always thrilled. A plan to build a six-mile-long, 20-foot-high sea wall around the coast of Miami prompted outrage: It would, after all, ruin the view. The plan was abandoned.

2. Live with it

The second approach is to accept that water will get in, so we should live with it. This entails elevating homes off the ground, as builders do in the Outer Banks or coastal Louisiana. It also means raising roads, power stations and other critical infrastructure — all at no small cost.

Another example of living with water is described in an excellent new piece from my colleague Rory Smith, who visited a coastal plain in southwest England that used to be farmland protected by a sea wall. Officials converted it into a marsh when they realized it was best just to open up flood barriers, turning the area into a giant sponge. Now, communities farther inland are less likely to flood.

Cities like Hoboken, N.J., have embraced this concept, building spaces designed to capture and hold storm water.

In Bradenton Beach, Fla. Callaghan O'Hare for The New York Times

 

 

 

3. Pack your bags

Sometimes those things don’t work. Then, and usually only then, communities resign themselves to simply leaving.

In 2016, the Obama administration provided $48 million to move Isle de Jean Charles, an island village of a few dozen families in Louisiana, away from the rising Gulf of Mexico. The single road to the mainland was frequently wrecked by storms, and, by common consensus, the community couldn’t be saved. It was the first climate-driven relocation project in the United States.

I visited Isle de Jean Charles to watch residents vote on where their new community should be built. Relocation — experts call it “managed retreat” — is about as hard as you might think. Few people are eager to leave, and there’s no guarantee that the community will remain intact.

Even so, the approach is becoming more common. Congress has passed millions of dollars to relocate Native American tribes, which often live on land dangerously vulnerable to flooding. Canada pushes some homeowners not to rebuild in the same place after a flood.

What now?

Behind those options is a puzzle: With so many tools available, why does flood damage in the United States (which cost more than $180 billion last year, according to one estimate) keep rising? I asked Chad Berginnis, head of the Association of State Floodplain Managers. “Two things,” he told me. “Irrationality and elections.”

People struggle to assess the danger when disasters are infrequent but incredibly costly, he said. And politicians realize they won’t become popular by raising people’s taxes to pay for colossal infrastructure projects.

With that in mind, Berginnis suggests a fourth option for flood protection: In especially high-risk areas, stop building new homes.

For more: I encourage you to read Rory’s article about how England surrendered farmland back to the water.

For more

• This summer, the U.S. government restricted building in flood plains.
• Last month, fueled by climate change, floods wreaked havoc across four continents.
• Real estate is booming in flood zones. Here’s why buyers risk it.
• Scientists are mapping landslide hazards in Alaska. Some homeowners don’t want to know.

 

Climate change: Islanders plan for flood-adapted homes

 

This Philippines island is continually flooding as sea level rise as a result of climate change.

There's a long term plan to relocate the residents, but is their own plan more sustainable?

Here's my latest for DW News Asia

Click here: Video 

 

 

 

 

Why we should care about airplane contrails

The climate impact of aviation could be three times higher than thought because of non-CO2 emissions like contrails

 by Anne-Sophie Brändlin

 
 Condensation trails or contrails — the white, feathery lines behind airplanes — could have as big an impact on the climate as the aviation sector's CO2 emissions. Here's why, and what we can do mitigate the effects.

 

When thinking of flying's environmental impact, the CO2 emitted from burning jet fuel is usually what springs to mind. But there's another, lesser understood climate culprit hiding in plain sight: condensation trails.  

The wispy, cloud-like formations left by airplanes as they traverse the skies may look innocuous, but the climate impact from 'contrails' could be similar to aviation CO2.

"I'm actually more worried about contrails at this point than I am about CO2 emissions because it is an impact that has not been internalized by the industry in any shape or form," said Jayant Mukhopadhaya, a lead aviation researcher for the International Council on Clean Transportation (ICCT), a US environment think tank. 

A 2021 study

suggests contrails and other non-CO2 emissions could account for up to two-thirds of aviation's total climate impact. Contrails could represent 57% of that impact — roughly the same as CO2 emissions from burning fuel. 

The aviation industry is currently thought to be responsible for 2 to 3.5% of global CO2 emissions annually. 

"But if you start taking into account these other pollutants that aviation is responsible for, the aviation sector is actually accounting for a far higher amount of warming than we usually ascribe to it," said Mukhopadhaya, adding that it could be three times greater than previously assumed.  

How are contrails formed and why are they a problem?

Contrails form when airplanes fly through very cold, humid pockets of air in the upper atmosphere. When plane engines burn jet fuel, water vapor condenses on particles from the air and exhaust to form ice crystals. If there are a lot of ice crystals, they make cirrus clouds.

"Some of them persist for only a few seconds or minutes, others for hours or even days, depending on the amount of moisture and the temperature," said Patrick Minnis, a senior NASA scientist researching the climate impact of contrails and the behavior of cirrus clouds. 

Contrail cirrus clouds trap heat in the atmosphere. The warming effects are worse at night when they're not also reflecting sunlight back into space.  

"Producing contrails is basically like wrapping a blanket around Earth every year that traps heat and warms the planet," said Mukhopadhaya.

How much warming do contrails cause?

While scientists say contrails cause warming, there's less consensus regarding the degree and timescale, as well as what they mean for climate change. 

"The exact magnitude of the warming impact of contrails is uncertain. The estimates range from 30% of the impact airplane of CO2 to as much as four times, so it's quite a large range," said Mukhopadhaya.

That's because there's a level of uncertainty in most contrail studies so far due to a lack of sufficient data. But it also comes down to the metrics scientists use to measure contrail impact. For instance, according to Mukhopadhaya, unlike for long-lasting CO2, it doesn't make sense to look at contrails over a 100-year period because they dissipate so quickly. 

"What we're interested in is how much global mean surface temperature changes because of these pollutants," said Mukhopadhaya. "And contrails could be responsible for roughly 15% of our available carbon budget to reach the 1.5 degrees goal by 2050." 

"There are direct incentives to reduce the climate impact of CO2 emissions. Those don't exist for contrails," said Mukhopadhaya

How to cut contrails' climate impact

As contrails are short-lived compared to CO2 emissions their warming impact would disappear quickly if efforts were made to minimize their formation, say experts.

One solution is switching to "cleaner" fuels with less sulfur, like hydrogen. This would reduce the amount of air pollutants released by jets and lower the life span of contrails, according to NASA's Patrick Minnis. 

Last year, the European Union introduced legislation

setting mandates for sustainable aviation fuels. By 2050, all jet fuels sold in European countries will have to consist of 70% "sustainable aviation fuels."

"That will help not only reduce the non-CO2 impact from aviation, it will also have a significant impact on the sector's CO2 emissions," Mukhopadhaya said.

Scientists have also found that not all flights create contrails in the first place. It all depends on weather conditions and the aircraft's trajectory. Rerouting less than 2% of flights in Japan could have reduced the warming effect of contrails by nearly 60%, a 2020 study

found.

But predicting beforehand which flight routes will cause contrails and how much warming these contrails will cause is very difficult. 

"You have to consider the atmosphere like a cake. The top layer of the cake is the upper atmosphere and within that there's all sorts of striations of moisture. So, knowing exactly where those layers are that have a lot of moisture in them is something that's been relatively difficult to predict," said Minnis.

Only a tiny propotion of the total flight distance is responsible for persistent contrails that cause warming

 

Proper prediction would require improvements in satellite work and a lot more expensive computer storage, added the NASA researcher. 

Flying planes lower has been touted as another solution because contrails form at higher altitudes but the "problem is that if you go to lower levels, you're going to have more turbulence, and you're going to use more fuel," Minnis said. And that means higher CO2 emissions.

"But we estimate the impact of those additional CO2 emissions to be significantly lower than the impact from contrail production," said ICCT's Mukhopadhaya.

More data needed 

A 2024 study by the International Air Transport Association (IATA)

, an industry trade body, suggests more data needs to be collected to understand the non-CO2 impacts of aviation so solutions can be found.

Improvements in satellite work could help mitigate contrail formation in the future

 

Airlines such as Lufthansa, Air France, KLM and American Airlines have already started contrail avoidance test flights above or below at-risk areas with the help of satellite images, weather data, software models and AI prediction tools.

"That's a great first step, as about 50% of warming due to contrails happens over the US, EU and the North Atlantic — three regions with high aviation activities," said Mukhopadhaya.

A 2024 Cambridge University report

suggests that accelerating the deployment of a global contrail avoidance system could reduce aviation's climate impact by 40%.

The EU has also agreed airlines will have to monitor and report the climate impact of contrails in a move opposed by the industry.

"The aviation industry has been delaying action for around 20 years now, driven by the lack of uncertainty regarding contrail science," said Mukhopadhaya. But the fact research is now being done in real life rather than on computer simulations is "very promising for avoidance measures in the future," he added. 

Edited by: Jennifer Collins