Richard Davy

By changing our diets now, we can avoid the food chaos that climate change is bringing By choosing to transform how we grow food and what we eat – rather than letting climate change dictate the pace of change – we have so much to gain.

By changing our diets now, we can avoid the food chaos that climate change is bringing, says @profpaulbehrens.bsky.social

- This trajectory of climate-driven food price hikes – leading to social unrest and political decay – is not inevitable

#climatecrisis
theconversation.com/by-changing-...

Black carbon emissions have been underestimated in the 'global south' Black carbon, the sooty byproduct of incomplete combustion of fossil fuels, has emerged as a major contributor to climate change and human health impacts. Researchers in the McKelvey School of Enginee...

Global datasets of black carbon emissions tend to be based on estimates of how much fuel is combusted incompletely. Comparing with actual measurements suggests these datasets have underestimated black carbon emissions in developing countries. 1/3

So how does that line up with your expectations of what makes for a good summer? Can we meaningfully quantify this?

#GoodSummerIndex #ClimateData #Weather #DataViz

Rome on the other hand:
Starting from a very good baseline of exceptional summers, but a clear negative trend with hotter and more intense heatwaves detracting from the overall experience.

Now look at Berlin.

📈 GSI is trending up — summers are getting better.

Why?

More sunny spells

More swimming weather
– But too much heat is now a downside.

Hotter ≠ better, once you’re sweating through 35°C.

But how is the quality of summers varying over time?

In Bergen the GSI since 1980 is chaotic — some gems, some write-offs, and no clear trends.

But the most important factors are crystal clear:
☀️ How warm is it?
☀️ How sunny is it?

Let’s zoom in on southern Norway 🇳🇴

Bergen is doing okay (for Bergen).
Oslofjord? Better.
But check out Kristiansand to Arendal — it really pops on the GSI.

There’s a reason so many people from Oslo head there for summer holidays.

Here’s how Europe looks so far for summer 2025 (June + July):

Coastal Mediterranean regions score high ✅
Further north = tougher summers ❄️

But zoom in, and the variability is interesting. ⬇️

The GSI looks at five things, each worth 20 points:

☀️ Sunny spells (3+ dry, clear days)
🌡️ Comfortable warmth (increasingly penalizing >30°C)
🏊 Swimmable conditions (warm, no rain)
🌧️ Avoiding long rainy stretches
🌓 Balanced across June, July, and August

Total score? 0–100. Simple, but revealing.

🌞 What makes a good summer?

I’ve been thinking about that a lot lately — and decided to quantify it.

Meet the Good Summer Index (GSI): a data-driven but human-centric score of summer quality, based on things people say they actually enjoy.

Thread 👇

Yes. This map showing how children’s right to roam free has been removed over four generations always makes me sad.

While there isn't a clear trend (often the case with noisy precipitation data!) we certainly haven't seen such early wet periods in recent history with 2016 and 2024 really standing out as having the earliest wet-periods.

Last summer was not so kind to us and we had a record-wet August. It got me wondering if we can expect more intrusions of heavy rain into the previously 'safe' periods in the summer, so I pulled up some reanalysis data to investigate this (see figure).

We've had a gloriously warm and sunny summer in Bergen this year. You really need this break in a city where you know the heavy rain is just around the corner.

If you're interested in sea ice and how we can track its development, you may want to sign up for our 1-day seminar where we'll be talking about the breadth of ECVs for sea ice, new developments in tracking sea ice age, and the pitfalls and opportunities of climate model - observation comparisons.

A black-and-white cartoon shows a trolley approaching a junction where its track splits into two directions. A person stands next to a lever, which can switch the trolley from one track to another. On the left track (the default path), there are five dolphins labeled “Not removing CO₂ from the atmosphere.” On the right track, there is one dolphin labeled “Deploying CO₂ removal (CDR).” The drawing suggests that not taking action to remove CO₂ may result in greater harm (symbolized by the five dolphins), while deploying CO₂ removal may have its own risks or costs (symbolized by the single dolphin), but is the comparatively better choice.

CO₂ removal (CDR) deployments require materials and energy, which emit CO₂. That’s why we talk about net CDR.

Even if CDR affects ecosystems, it’s likely minor compared to the significant negative impacts of climate change on ecosystems. So we should focus on the net ecosystem benefits of CDR.

💡 Take-away: evening heat lingers—especially in dense urban fabrics—long after the later-night minimum cools down. If we ignore the 10 pm metric, we’re underestimating heat stress & sleep loss for millions.

What 2025 looks like (so far):
• 🇮🇹 Rome — hot either way
• 🇫🇷 Paris — few tropical nights, 30+ tropical 10 pms (!).
• 🇳🇴 Oslo — zero tropical nights, but a whole week of tropical 10 pms.
• 🇵🇹 Lisbon & 🇦🇹 Vienna — ~7 tropical nights, ~30 tropical 10 pms each.

This is a typical picture for these cities

🕙 Tropical 10 pm = ≥ 20 °C at 10 pm local time. That’s when your body tries to cool for sleep, not at 4 am when the official “night-minimum” is set. Delayed sleep onset = fatigue, heart strain, lost productivity.

Bar chart for Lisbon, Oslo, Paris, Rome, Vienna showing blue bars (tropical nights) vs orange bars (tropical 10 pms) in 2025 so far. Orange bars tower over blue in every city except Rome, highlighting bedtime heat.

🌡️ Not all hot nights are equal. We track “tropical nights” when temps never dip below 20 °C—but what if it’s already 20 °C at bedtime? I crunched ERA5 data for 5 European capitals. Let’s talk tropical 10 pm. 👇

If you're interested in sea ice and how we can track its development, you may want to sign up for our 1-day seminar where we'll be talking about the breadth of ECVs for sea ice, new developments in tracking sea ice age, and the pitfalls and opportunities of climate model - observation comparisons.

Drowning Doesn’t Look Like Drowning Drowning is not the violent, splashing call for help that most people expect.

Thanks for the reminder @janemunday.bsky.social. Every summer, I repost this article DROWNING DOES NOT LOOK LIKE DROWNING. To date, I know of FOUR kids who were saved after someone who'd clicked on the link learnt how to spot actual drowning. Take time to read and pass on.

slate.com/technology/2...

Do you have a PlayStation?

If so, Climate Station has launched as a free immersive and compelling data-driven experience of our planet:
blog.playstation.com/2025/06/18/c...

(and @playstation.com have joined #ShowYourStripes!)

The Bank of England just raised the bar on climate risk supervision.
Boards are now expected to own climate risk.
Scenario analysis must be routine.
Data quality and disclosures? Under scrutiny.
What does it mean for the financial sector—and how can we help?
#climaterisk #BoE #finance #governance

This iconic NASA office changed climate science forever. DOGE plans to kill it The NYC space is where the term ‘black hole’ was coined and where James Hansen became famous for his warnings about climate change.

we’re getting evicted, it’s stupid, and I’m mad

www.fastcompany.com/91333946/thi...

Norway's Marine Heatwave: What the Experts Are Seeing Fish n' Bits - The Aquaculture Data Intelligence Podcast · Episode

Interested in the risk of marine heatwaves along the Norwegian coast this summer? Listen to my colleague, Dr Langehaug, discussing the state of the art on the Fish n' Bits podcast:
open.spotify.com/episode/0iok...

@nansensenteret.bsky.social

I thought Dragon was going to be how I wrote my thesis after a hand injury, but it was so much frustration!

~45% of US corn production is now used to make ethanol, mostly for mixing into gasoline.

That's ~13% of all US crop land already used for energy production.

Using some of the same land for solar panels would capture 50-100 times more energy per acre.

Kelvin-Helmholtz waves looking all the more dramatic for catching the evening light

📣 Job Vacancy 📣

The University of St Andrews is seeking to enhance its research strength in Statistics by appointing a new Chair in Statistical Ecology. Closing date 21/07/2025.

www.vacancies.st-andrews.ac.uk/Vacancies/I/...