🔥 37.1 and Rising - Fionn's Green Journey
Hey Eco Champions,
This one’s coming to you from the middle of Zürich’s hottest June on record… 37.1°C, beating the 2003 mark, with a July that hasn’t exactly let up either. Between the heat, a week on the glacier for a Hochtouren Kurs, and far too much lake time, it’s been a full few months. More on all of that below.
But first, the reason I actually wanted to write this edition: a new attribution study just came out that puts real numbers on this heat wave, and it’s some of the sharpest climate science I’ve read in a while. Let’s get into it.
The Science: Quantifying an Unprecedented Heat Wave
Across Europe, this summer’s heat waves are provisionally linked to 10,000–20,000 excess deaths, depending on the model. Most of this happened quietly, indoors, among people over 65, which is part of why it hasn’t registered as the mass-casualty event it is.
What generated it. The driver was an omega block: a high-pressure system wedged between two low-pressure systems, tracing the shape of Ω in the upper atmosphere. Once locked in, there’s no front to break it up. Hot, dry air pulled north from the Sahara sat over Western Europe from late June, easing briefly before reloading in July. Temperatures ran 14–18°C above seasonal norms. Germany hit a provisional national record of 41.7°C; Spain reached 45.1°C in Andújar; the UK broke its June record three days running, as did Switzerland.
The new research. A rapid attribution study just published by World Weather Attribution (WWA Scientific Report No. 85, Keeping et al., 2026) quantified exactly how much human-caused warming altered this event. Their key finding: a heat wave with this circulation pattern is now about 3.5°C hotter during the day than it would have been in 1976, and roughly 2°C hotter than in 2003, the same weather pattern, but a hotter baseline climate underneath it. The study also used a wet-bulb globe temperature (WBGT) metric which combines heat, humidity, and radiant heat to capture what the body actually experiences and found that 45% of the ~850 European cities analyzed broke or were forecast to break their all-time heat-stress thresholds during this event. Researchers were also able to rule out a confound: El Niño was not a contributing factor, isolating anthropogenic warming as the driver.
Why Europe absorbs this so badly. Only around 20% of European homes have air conditioning, and much of the housing stock was built to retain heat for winter — thick walls, small windows, poor ventilation, an asset in January and a liability at 40°C. Europe is warming at roughly twice the global average and already has the highest per-capita heat mortality of any continent. The WWA report notes heat risk concentrates in cities, where urban heat island effects compound with ageing building stock and socioeconomic inequality.
The Swiss dimension. Alpine snowpack and glacier meltwater are supposed to arrive on a gradual, predictable summer schedule, feeding both drinking water supply and hydropower. A worst-case melt season front-loads that water releasing it faster than downstream infrastructure and ecosystems are built to absorb.
What the Data Says to Do
Now: Check on people over 65, especially those living alone, they account for the overwhelming majority of heat deaths. Shutter windows by day, ventilate only once outdoor air actually cools at night.
Longer term: World Resources Institute data ranking individual climate actions by real emissions impact found living car-free is roughly 78 times more impactful than composting. The top three levers, in order: going car-free (or car-light), flying less, switching home energy to renewables. A separate Stanford-led study on collective climate action found guilt-based messaging doesn’t work, but showing people that past collective action produced real structural change does.
What I’m Up To
Grinding forward on the PhD at ETH
Completed a Hochtouren Kurs with Bergführer Sigi Schönthal, SAC UTO
Alpine trips with Kaan, Lennart, Martin, Felix, Joris, May, and Noemi
The Lenzspitze–Nadelhorn traverse, two 4000m summits, one epic day
Lake time, a lot of it
Working through some anxiety this year, and feeling genuinely better
A wonderful trip to Lyngen visiting my Svalbard friend Marion. Thank you for the incredible hospitality :-)
Something new brewing for the next few months… more soon
Things I’m Loving
WBGT as a concept — a single number that finally captures what heat actually does to the body, not just what the thermometer says
The A50 motorway downgrade near Zürich: four lanes to two, 12 hectares handed back to farmland and wildlife habitat
Cold ramen, my heat wave staple: boil noodles, shock them in ice water, toss in a dressing of soy sauce, sesame oil, rice vinegar, tahini, and grated garlic, then top with a soft-boiled egg, cucumber, and chili oil. Eat outside, ideally near water.
Gaspacho by the lake Just try it!
Stay cool out there (easier said than done, I know), and if you find a shady spot by the lake, save me one.
Until next month,
Fionn 🌲
This edition of Fionn’s Green Journey is fully carbon offset, thanks to the amazing support from Atlas Project! Each tree emoji below represents a verified tree planted to offset our digital footprint. 👣
🌟 This Month: A new Mango has taken root! 🥭
Fionn’s Green Journey Forest
🌲 🌳 🌴 🌿 🥑 🌴 🌿 🌳 🌲 🌳 🥭 🌴 🌴 🌺 🥭 🌲 🥑 🌲🥭
🌲 = White Fir, 🌳 = Black Ironwood, 🌴 = Indian Cedar, 🌿 = Red Mangrove, 🌺 = Pomegranate, 🍋 = Lemon, 🥑 = Avocado, 🥭 = Mango
Watch the forest grow with every edition. Feel free to request exact coordinates 🥾✨