Rising temperatures across France since the mid-1970s is putting Tour de France competitors at “high risk”, according to new research.
The study, published in Scientific Reports, uses 50 years of climate data to calculate the potential heat stress that athletes have been exposed to across a dozen different locations during the world-famous cycling race.
The researchers find that both the severity and frequency of high-heat-stress events have increased across France over recent decades.
But, despite record-setting heatwaves in France, the heat-stress threshold for safe competition has rarely been breached in any particular city on the day the Tour passed through.
(This threshold was set out by cycling’s international governing body in 2024.)
However, the researchers add it is “only a question of time” until this occurs as average temperatures in France continue to rise.
The lead author of the study tells Carbon Brief that, while the race organisers have been fortunate to avoid major heat stress on race days so far, it will be “harder and harder to be lucky” as extreme heat becomes more common.
‘Iconic’
The Tour de France is one of the world’s most storied cycling races and the oldest of Europe’s three major multi-week cycling competitions, or Grand Tours.
Riders cover around 3,500 kilometres (km) of distance and gain up to nearly 55km of altitude over 21 stages, with only two or three rest days throughout the gruelling race.
The researchers selected the Tour de France because it is the “iconic bike race. It is the bike race of bike races,” says Dr Ivana Cvijanovic, a climate scientist at the French National Research Institute for Sustainable Development, who led the new work.
Heat has become a growing problem for the competition in recent years.
In 2022, Alexis Vuillermoz, a French competitor, collapsed at the finish line of the Tour’s ninth stage, leaving in an ambulance and subsequently pulling out of the race entirely.
Two years later, British cyclist Sir Mark Cavendish vomited on his bike during the first stage of the race after struggling with the 36C heat.
The Tour also makes a good case study because it is almost entirely held during the month of July and, while the route itself changes, there are many cities and stages that are repeated from year to year, Cvijanovic adds.
‘Have to be lucky’
The study focuses on the 50-year span between 1974 and 2023.
The researchers select six locations across the country that have commonly hosted the Tour, from the mountain pass of Col du Tourmalet, in the French Pyrenees, to the city of Paris – where the race finishes, along the Champs-Élysées.
These sites represent a broad range of climatic zones: Alpe d’ Huez, Bourdeaux, Col du Tourmalet, Nîmes, Paris and Toulouse.
For each location, they use meteorological reanalysis data from ERA5 and radiant temperature data from ERA5-HEAT to calculate the “wet-bulb globe temperature” (WBGT) for multiple times of day across the month of July each year.
WBGT is a heat-stress index that takes into account temperature, humidity, wind speed and direct sunlight.
Although there is “no exact scientific consensus” on the best heat-stress index to use, WBGT is “one of the rare indicators that has been originally developed based on the actual human response to heat”, Cvijanovic explains.
It is also the one that the International Cycling Union (UCI) – the world governing body for sport cycling – uses to assess risk. A WBGT of 28C or higher is classified as “high risk” by the group.
WBGT is the “gold standard” for assessing heat stress, says Dr Jessica Murfree, director of the ACCESS Research Laboratory and assistant professor at the University of North Carolina at Chapel Hill.
Murfree, who was not involved in the new study, adds that the researchers are “doing the right things by conducting their science in alignment with the business practices that are already happening”.
The researchers find that across the 50-year time period, WBGT has been increasing across the entire country – albeit, at different rates. In the north-west of the country, WBGT has increased at an average rate of 0.1C per decade, while in the southern and eastern parts of the country, it has increased by more than 0.5C per decade.
The maps below show the maximum July WBGT for each decade of the analysis (rows) and for hourly increments of the late afternoon (columns). Lower temperatures are shown in lighter greens and yellows, while higher temperatures are shown in darker reds and purples.
Six Tour de France locations analysed in the study are shown as triangles on the maps (clockwise from top): Paris, Alpe d’ Huez, Nîmes, Toulouse, Col du Tourmalet and Bordeaux.
The maps show that the maximum WBGT temperature in the afternoon has surpassed 28C over almost the entire country in the last decade. The notable exceptions to this are the mountainous regions of the Alps and the Pyrenees.
The researchers also find that most of the country has crossed the 28C WBGT threshold – which they describe as “dangerous heat levels” – on at least one July day over the past decade. However, by looking at the WBGT on the day the Tour passed through any of these six locations, they find that the threshold has rarely been breached during the race itself.
For example, the research notes that, since 1974, Paris has seen a WBGT of 28C five times at 3pm in July – but that these events have “so far” not coincided with the cycling race.
The study states that it is “fortunate” that the Tour has so far avoided the worst of the heat-stress.
Cvijanovic says the organisers and competitors have been “lucky” to date. She adds:
“It has worked really well for them so far. But as the frequency of these [extreme heat] events is increasing, it will be harder and harder to be lucky.”
Dr Madeleine Orr, an assistant professor of sport ecology at the University of Toronto who was not involved in the study, tells Carbon Brief that the paper was “really well done”, noting that its “methods are good [and its] approach was sound”. She adds:
“[The Tour has] had athletes complain about [the heat]. They’ve had athletes collapse – and still those aren’t the worst conditions. I think that that says a lot about what we consider safe. They’ve still been lucky to not see what unsafe looks like, despite [the heat] having already had impacts.”
Heat safety protocols
In 2024, the UCI set out its first-ever high temperature protocol – a set of guidelines for race organisers to assess athletes’ risk of heat stress.
The assessment places the potential risk into one of five categories based on the WBGT, ranging from very low to high risk.
The protocol then sets out suggested actions to take in the event of extreme heat, ranging from having athletes complete their warm-ups using ice vests and cold towels to increasing the number of support vehicles providing water and ice.
If the WBGT climbs above the 28C mark, the protocol suggests that organisers modify the start time of the stage, adapt the course to remove particularly hazardous sections – or even cancel the race entirely.
However, Orr notes that many other parts of the race, such as spectator comfort and equipment functioning, may have lower temperatures thresholds that are not accounted for in the protocol, but should also be considered.
Murfree points out that the study’s findings – and the heat protocol itself – are “really focused on adaptation, rather than mitigation”. While this is “to be expected”, she tells Carbon Brief:
“Moving to earlier start times or adjusting the route specifically to avoid these locations that score higher in heat stress doesn’t stop the heat stress. These aren’t climate preventative measures. That, I think, would be a much more difficult conversation to have in the research because of the Tour de France’s intimate relationship with fossil-fuel companies.”
The post Dangerous heat for Tour de France riders only a ‘question of time’ appeared first on Carbon Brief.
Dangerous heat for Tour de France riders only a ‘question of time’
SYDNEY, Thursday 30 October 2026 — In response to reports that the Albanese government is set to introduce draft legislation this year that would seek to ban data centres in Australia’s suburbs, Joe Rafalowicz, Head of Climate and Energy at Greenpeace Australia Pacific, said:
“These reports are a testament to the growing community opposition to these completely inappropriate AI factories that have sprung up across our suburbs, and Big Tech corporations should take heed — the data centre build-out must not happen without the endorsement of the Australian people.
“But the government can’t simply ship this problem out to regional Australia without addressing the fundamental issues with this extractive new industry.
“We’re already seeing a trend of AI data centre proposals moving to the regions, in areas that are more water-scarce, more environmentally sensitive, and next to sources of fracked and coal seam gas to support their massive BYO gas-fired power plans — a pattern we’ve seen play out in the United States.
“From the Beetaloo Basin in the NT to the Western Downs in Qld, we’re seeing a wave of AI data centre proposals that would see new gas fast-tracked to support their massive energy demand, and threaten to completely derail Australia’s energy transition.
“Just as suburban Australians are asking, “what for?”, regional communities like Berry Springs and Dalby do not want dirty data centres setting up shop with absolutely no benefit to their communities. Greenpeace is calling for a moratorium on AI data centre developments until strict and enforceable safeguards are in place to protect our climate and our communities.”
-ENDS-
Media contact
Kate O’Callaghan on +61 406 231 892 or kate.ocallaghan@greenpeace.org
AI data centre ban in suburbs would not address fundamental issues: Greenpeace
In the thick of the COP29 climate summit in Azerbaijan in 2024, the UN climate talks were rattled by what can only be described as a major PR disaster. The BBC, Reuters and The Guardian all carried headlines, attributed to leading climate policy experts, that the COPs were “no longer fit for purpose”.
The articles outlined a series of reforms called for in an open letter signed by 22 eminent scientists and politicians, including a former UN secretary-general and previous UN climate chief, with a further 150 lending their support. The headlines shook confidence in the COP process, just as governments were wrestling over a new climate finance goal.
The Club of Rome – which handled the media relations for the letter – hurried to say that its “constructive, supportive ideas” had been “misinterpreted”. Negotiators kept calm(ish) and carried on, in the end landing the finance goal after some high-stakes drama on the final day.
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Early speakers’ list suggests few powerful leaders will attend COP31
Just 77 heads of state or government are scheduled to address the COP31 climate summit in Antalya, a third less than the COP28 peak -
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The African Group wants dedicated space on tripling adaptation finance, the Green Climate Fund and trade, setting up a possible clash
To my surprise, when I went back this week to read the letter again, I could not find the offending line about the COPs not being fit for purpose. The Club of Rome has yet to respond to my query about its disappearance.
Whatever happened to the wording, that sentiment has been widely shared. COPs have ballooned in size while the importance of their outcomes seems to have diminished since the 2015 Paris Agreement (with the exception of the 2023 COP in Dubai where countries agreed to transition away from fossil fuels in energy systems).
The same on the surface
Two years on from those painful headlines in Baku, has anything changed for the better? You might be forgiven for thinking not. Official decisions are still made by consensus rather than the majority voting some have called for to stop blockers.
Tens of thousands of officials, activists and business execs still scurry around the halls to an ever-growing list of side events, roundtables and dialogues, while deals still come down to rows, all-nighters and jargon-filled texts adopted to rounds of applause.
But it would not be true to say that COPs have completely failed to respond to the very real need to translate the words of the Paris Agreement into action in the outside world.
Global warming is projected to be around 1.3C lower this century than it would have been if the world had not committed to tackle the climate crisis under that accord. Developing countries have a valued space at COPs in which their voices have equal weight in decision-making, unlike in many other international fora. And most importantly, perhaps, there has been a subtle shift, tipping the balance away from negotiating towards doing.
Brazil branded last year’s summit in Belém as the “COP of Implementation”, corralling the sprawling Action Agenda into six axes. This was a bid to impose some structure on the mushrooming efforts between governments, UN agencies, cities, businesses and civil society to set targets and spur faster results on their pet issues, from methane emissions to health and adaptation in conflict zones. COP30 alone saw the launch of 120 “plans to accelerate solutions”.
COP30 roadmaps off the cuff
Meanwhile, as the formal negotiations drew to a close, it was clear that consensus decision-making was evolving into something a little more improvised.
With only around half of all countries on board with the idea of a roadmap to transition away from fossil fuels, COP30 President André Corrêa do Lago announced his team would put one together over the coming year, along with another on how to meet a global goal to halt deforestation by 2030. Those roadmaps will be launched next week, presented and discussed at COP31, though it’s still unclear whether or how they’ll be incorporated into the formal negotiating agenda.
Some leading policy-makers don’t think that matters too much. Speaking to journalists before the Antalya summit, COP30 CEO Ana Toni and Dutch climate minister Stientje van Veldhoven said “coalitions of the willing” can move ahead without needing consensus from the COPs. This, they said, was evident this year at the first global conference on TAFF, co-chaired by van Veldhoven and attended by 60 countries.
“Consensus or no-consensus in the general COP doesn’t make a difference for the choices I have to make in my country to get my country to phase out fossil fuels,” said the Dutch minister. The Netherlands recently became one of the first to publish a national TAFF plan.
COP31 banks on flagship voluntary initiatives
This thinking has permeated the management and expected outcomes of this year’s COP too. Earlier this year, Türkiye, supported by international energy agencies, floated the idea of a voluntary goal to boost electrification to 35% of the world’s final energy consumption by 2035 – and this is now being touted as one of the main results to be expected from Antalya.
Türkiye is also championing a pledge on AI and climate, while co-host Australia is pushing to ease access to climate finance for least developed countries and small island states.
COP31 presidency announces AI pledge as UN climate chief says Big Tech ‘on thin ice’
None of these needs consensus. But with a political cover decision already in the works, as trailed by the COP presidents, they – and perhaps the fossil fuel roadmap – may find a home in the official text if language acceptable to most can be found, giving them them additional weight.
UNFCCC reform process in the shadows
Formal reform is underway too, if quietly. UN climate chief Simon Stiell is leading a review informed by ongoing consultations with a group of 15 well-respected climate policy experts, three of whom signed the open letter in 2024.
Among them is leading Swedish climate and sustainability scientist Johan Rockström who has strong ideas about how to make COPs function better, including a switch to majority voting. He told the same press briefing nothing stands in the way of this, because the rules of procedure for making decisions at COPs have never been formally agreed.
Still, to get away from the default setting of consensus would require agreement on a new system that may be impossible to achieve given the rise in bullying tactics by fossil fuel heavyweights.
Comment: The UN climate process was built for negotiation – now it must support implementation
The deliberations with the high-level policy gurus, as reflected in a summary of June’s session in Bonn, largely echo what’s already happening organically, calling for stronger partnerships and accountability both in and between the Action Agenda and negotiations. It doesn’t mention voting.
A general overview of the reform exercise says that “improving and optimizing the [UN climate] process over the medium to long term… will be critical to fostering trust, enhancing collaboration, and catalyzing increased ambition”.
In the short term, don’t hold your breath for anything concrete on reform at COP31 but watch for signs in what ends up dominating the headlines from Türkiye.
The post Editor’s Desk: COP reform is happening quietly, behind the headlines appeared first on Climate Home News.
Editor’s Desk: COP reform is happening quietly, behind the headlines
With the COP31 climate summit in Turkey looming, all eyes are on China to see what the country will push for in the negotiations.
At COP30 last year, China helped to secure a “dialogue” on climate-related “unilateral trade measures”, as well as a two-year “work programme” concerning climate finance.
The nation also championed south-south cooperation throughout the conference and co-led a summit on methane, alongside Brazil and the UK.
In a recent press conference, China’s environment vice-minister Li Gao noted the need to “uphold multilateralism” and send a “clear political signal” that the global community is united around climate action.