DeBriefed 26 June 2026: Heat records broken across Europe

DeBriefed 26 June 2026: Heat records broken across Europe | London climate action week | Introducing ‘Project Cosmos’ Multiple Authors 06.26.26Multiple Authors 26.06.2026 | 3:27pmWelcome to Carbon Brief’s DeBriefed. An essential guide to the week’s key developments relating to climate change. This week Record Europe heat HOTTEST EVER: The UK broke its temperature record for June twice this week, while France recorded its hottest day ever two days in a row, reported the Guardian. The Times reported that temperatures reached 36.7C in Somerset on Thursday, as the “London Ambulance Service had its busiest-ever day for life-threatening emergencies”. FRANCE FRYING: French newspaper Libération said that temperatures reached as high as 44.3C in the south-western commune of Pissos on Wednesday. Spain also recorded its highest daily average temperature for June, said BBC News. On Thursday, Switzerland also had its hottest June day, when temperatures reached 37C in four locations, reported SwissInfo. CLIMATE LINK: CNN covered a rapid analysis from the World Weather Attribution service finding that fossil-fuelled climate change has made this heatwave the most severe and widespread in Europe’s history. Carbon Brief covered the broken heat records, explaining the influence of climate change. ‘Electrifying’ London talks ‘LONDON COOKING’: In a sweltering, packed-out event at London climate action week, UN chief António Guterres quipped that “London is not just calling, it’s cooking”, reported Edie. Guterres also used his address to release a “global call to action on methane” and to call on artificial intelligence companies to reveal their environmental impact and source their power solely from renewables by 2030, said the publication. ‘ELECTRIFY NOW’: Elsewhere, dozens of governments, led by the EU and the UK, committed to throwing “their political weight” behind a rapid electrification of the world’s economy, according to Climate Home News. A high-level summit in London’s Mansion House saw energy ministers and business leaders, joined by Guterres, in “calling for faster action to curb demand for oil, coal and gas by powering homes, industry and transport with clean electricity”. FOSSIL TRANSITION: At the same event, ministers from Colombia and the Netherlands, the co-hosts of the world’s first summit on transitioning away from fossil fuels in April, unveiled a report on their key takeaways. It comes after the current Colombian government has been ousted by a presidential election defeat to a fossil-fuel-supporting Trump ally. Carbon Brief examined what this could mean for the world’s energy transition. Around the world - UK TARGET: The UK parliament has approved its “seventh carbon budget”, aimed at cutting emissions 87% below 1990 levels by 2040. - TOTAL ACCOUNTABILITY: A French court has ordered oil-and-gas giant TotalEnergies to account for the emissions from the use of its products, following a case brought by a climate NGO, reported Le Monde. - METHANE RULES: The US, Qatar and other major energy exporters have urged the EU to “rewrite planned methane emissions” rules for oil-and-gas imports, saying that the policy could disrupt fuel supplies to Europe, according to Reuters. - CHINA MESSAGE: China’s special envoy for climate change, Liu Zhenmin, said at the World Economic Forum that energy shortages triggered by the Iran war should be a “lesson to countries to accelerate their energy transitions”, reported Bloomberg. - US WEBSITE REVIVED: Former US government workers have “recreated a valuable climate-science website” shut down by the Trump administration last year, said the New York Times. 6,600 animals The number of livestock that perished in transport during heat in England and Wales from June to August 2025, double the number killed the year before, reported Carbon Brief. Latest climate research - Some world regions are experiencing up to 50 additional heat stress days annually, when compared to 1950 | Nature Climate Change - Projections of national land-use emissions to 2100 suggest the strongest “carbon sinks” will be in China and Indonesia, whereas Brazil and the Democratic Republic of the Congo will “dominate global sources” | Nature - Most carbon-offset projects relying on “avoided deforestation” have “mixed, negligible or negative impacts relative to control areas” | Nature Climate Change (For more, see Carbon Brief’s in-depth daily summaries of the top climate news stories on Monday, Tuesday, Wednesday, Thursday and Friday.) Captured The UK government’s official climate advisers, the Climate Change Committee (CCC), has released its latest progress report, emphasising that faster electrification is the best way to secure lower energy bills and stronger energy security. Electrification has shot up the agenda in recent months, with the COP31 presidency calling for countries to back a global goal for 35% of “final” energy to come from electricity by 2035. The text of the CCC’s latest report uses the word “electrification” far more often than previous editions, as shown in the figure above. See Carbon Brief’s in-depth breakdown of the CCC’s latest advice. Spotlight Introducing ‘Project Cosmos’ Carbon Brief explains how it built a major new database of climate science research and unveils a new ranking of the 500 most highly cited publications, authors and institutions in climate science. This week, Carbon Brief launched Project Cosmos – the world’s largest and most complete database of climate change research. The database features more than 1.8m academic papers, books and reports, capturing the vast body of human knowledge about climate change that has accumulated over more than a century of academic study. The climate science “universe” is based on reports from the Intergovernmental Panel on Climate Change (IPCC), which are recognised as the world’s most authoritative summaries of the latest climate science. Since its first report was published in 1990, humanity’s knowledge about human-caused climate change has ballooned. The IPCC has published six sets of reports in total – each one longer than the last. In total, IPCC reports reference more than 100,000 other papers, books and reports. This is the core of our climate science universe. Carbon Brief then built on this core, by looking at four other sources of data. Read more about how the Cosmos database was created here. Every single publication in the Cosmos database is linked to at least one other through references. Visualising these links reveals a “galaxy” of references. In the image above, each colour and cluster reveals different topics and densities of research. Explore the galaxy in an interactive map. Cosmos 500 As part of an initial wave of preliminary analysis to demonstrate the scope of the Project Cosmos database, Carbon Brief has ranked the 500 most highly cited publications, authors and institutions in the database. The most highly cited climate scientist is Prof Philippe Ciais, who has spent almost four decades researching the planet’s carbon cycle – and the ways in which humans have been impacting its balance. Carbon Brief recently interviewed Ciais in Paris. The US tops the tables for the most highly cited authors and institutions. Almost half of the 500 most highly-cited authors are from US institutions. This raises particular concerns for the future of climate science, as US climate scientists and institutions are coming under attack under the Trump administration. Experts from global south countries account for only 4% of all authors in the Cosmos 500. China stands out as the most highly-cited global south country. Meanwhile, only 10% of authors in the Cosmos 500 are women. There are many possibilities for future avenues of research using the Cosmos database. Over time, the database could be used to reveal, for example, how interest in different areas of climate science has changed over time, plus identify potential knowledge gaps and, thus, opportunities for future research. Carbon Brief invites researchers – including academics, journalists and analysts – to submit their own proposals for co-authored studies, literature reviews and analytical projects. Proposals should be sent to cosmos AT carbonbrief DOT org. This spotlight first appeared in Cited, Carbon Brief’s new fortnightly newsletter focused on climate research. Sign up for free. Watch, read, listen ‘DOOMSDAY CULT’: OpenDemocracy reported on a “religious cult” spreading climate misinformation in “parliaments” and at “COP summits”. ‘WEDGES’ EXAMINED: ProPublica and Drilled released an investigation into how oil executives worked to influence a climate research paper from Princeton University known as “wedges”. ‘1976 to 2056’: A 30-minute YouTube video from the Met Office had climate scientists explaining how current UK temperatures compare to the infamous 1976 heatwave, and how extremes could worsen by 2056. Coming up - 29-30 June: Hamburg sustainability conference, Hamburg, Germany - 29-30 June: Seventh global conference on climate and sustainable development goals synergies, Bangkok, Thailand - 29-30 June: 11th annual global conference on energy efficiency, Montreal, Canada Pick of the jobs - Drilled, series editor | Salary: $4,000 a month (six-month contract). Location: US - Met Office, ocean climate science manager | Salary: £54,515-£58,582. Location: Exeter, UK - Grantham Research Institute on Climate Change and the Environment, research officer (climate science and law) | Salary: £43,277-£55,497. Location: London DeBriefed is edited by Daisy Dunne. Please send any tips or feedback to [email protected]. This is an online version of Carbon Brief’s weekly DeBriefed email newsletter. Subscribe for free here.