INVESTIGATION • People work less effectively when it’s very hot. This rather down-to-earth observation is presented as an important explanation for why this summer’s heat could cost the EU around one percent of its GDP. But behind the dramatic figures lie many more assumptions and uncertainties than what is reported by Sweden’s Radio’s Science Desk.

Anyone who has ever tried to dig a ditch, lay asphalt, or just concentrate at a computer in a thirty-degree room can now feel scientifically validated – it is indeed harder to work when it’s hot.

According to a new analysis from the Dutch Triodos Bank, this summer’s heat and drought could reduce the EU’s GDP by about one percent in 2026 – approximately 180 billion euros. The largest single factor is said to be decreased labor productivity.

“You simply work a bit worse when it gets very hot,” says Olof Johansson Stenman, professor of economics at the University of Gothenburg, in a segment on Swedish Radio.

It’s hard to argue with that specific conclusion. People in warmer parts of the world have known about this phenomenon far longer than modern climate research. In places like Spain, workdays have traditionally been adapted to the heat, with the classic siesta scheduling rest during the day’s hottest hours.

The fact that high temperatures can make heavy physical labor less efficient is hardly a new discovery. The more interesting part is how large the economic effect actually is.

The Bank Calculates 180 Billion Euros

Triodos Bank’s analysis estimates the overall GDP effect for the EU at about minus one percent. In addition to labor productivity, the bank also factors in lower agricultural production, transport disruptions, and challenges for energy production.

The authors themselves emphasize that the calculations contain uncertainties and that effects partially overlap. This is not a measured loss of 180 billion euros, but a model-based estimate of the potential impact. This distinction disappears when the result is turned into a headline by Swedish Radio’s Science Desk.

Triodos Bank is also not a research institute, but a Dutch bank with a pronounced activist approach toward so-called green sustainability and financing the “green transition.” This does not necessarily mean their calculations are incorrect, but there is a risk and it is relevant information to provide to listeners during a Public Service segment when the bank’s analysis is presented as objective scientific evidence for climate policy conclusions.

The Expert Has Another Role Too

Swedish Radio presents Olof Johansson Stenman as a professor of economics at the University of Gothenburg. That is correct – but it’s not the whole story.

Johansson Stenman’s research mainly focuses on so-called environmental economics and he is also vice chair of the Swedish Climate Policy Council, a government agency formed by the Social Democrats and the Green Party in 2018 to officially review the government’s policies regarding Sweden’s climate goals, but which has been criticized for engaging more in climate activism than impartial government work.

This is relevant information in this context, not least because the segment ends with Johansson Stenman agreeing with the authors’ climate policy conclusion.

“Generally, most experts agree that globally, far too little is being done, especially to reduce emissions.”

The listener, however, is not told that the interviewed expert also sits on the board of the authority whose task is to evaluate climate policy, which has repeatedly criticized the government’s policy and, now during the election campaign, written op-eds that indirectly support the red-green parties.

This does not automatically mean his assessment is entirely wrong. But it is background information that’s generally journalistically relevant to inform media consumers of when an expert comments on a politically charged issue, especially during an election in which the climate issue takes a prominent place.

Sweden Simultaneously Absorbs More Than It Emits

There is also a complication in the discussion about Swedish “net emissions” that is rarely highlighted. The Swedish Environmental Protection Agency’s final climate statistics show that Sweden’s territorial emissions in 2024 amounted to 48.1 million tonnes of carbon dioxide equivalents, excluding the land use sector. At the same time, the net uptake within land use, land use change, and forestry amounted to about 54 million tonnes.

In purely physical terms, this means that Sweden’s reported net uptake was larger than its territorial emissions that year.

This does not mean Sweden has formally already met the politically defined net zero target for 2045. But the climate target is, after all, politically defined and contains special rules on which emission reductions and complementary actions can be counted – rules that may be challenged from a scientific and objective perspective and may be connected to an underlying agenda.

But the difference between the actual national greenhouse gas balance and the accounting rules of the climate targets is important. For the Climate Policy Council to talk about the “net zero 2045” ambition without mentioning that Sweden’s reported land and forest uptake already exceeds territorial emissions in some years gives the public a misleading idea of what the concept means.

Less Smart in the Heat?

Swedish Radio goes a step further than noting that people work slower as the thermometer rises. The calculations are also said to be based on the idea that we, “put simply, become less smart when it gets too hot.”

There is research that shows high temperatures can affect certain cognitive performances, particularly concentration and attention. But saying people become “less smart” is a far broader claim and moreover confuses intelligence with temporarily impaired ability to perform.

That someone calculates slower or has more difficulty concentrating in an overheated room hardly means their intelligence has dropped. A bit more of the precision usually associated with a science desk would have been appropriate here.

Tens of Thousands “Dead from Heat”

Things get even more dramatic when Swedish Radio states that the report notes “tens of thousands of deaths caused by the heat.”

Such figures might mislead listeners into believing that tens of thousands of death certificates state extreme heat as the direct cause of death. Estimates of heat-related mortality are mainly statistical, comparing observed deaths during hot periods to those that models estimate would have occurred otherwise.

The vast majority of people dying during heat waves are elderly or have cardiovascular, pulmonary, or other serious underlying conditions. The heat can then be a contributing or triggering factor but not the cause of death.

This does not make the effect unimportant. But “estimated heat-related excess mortality” is more precise than, as Swedish Radio’s Science Desk puts it without further explanation, saying that heat “caused” tens of thousands of deaths.

And Then the Fires

Swedish Radio also mentions this year’s record-setting wildfires, even though they are not included in the GDP calculation itself. Here too, more caution with causality is needed than the state broadcaster employs.

High temperature, drought, and wind can create conditions where fires spread more easily and are harder to put out. But that does not automatically mean that a given fire started due to these factors.

READ ALSO: 162 arrested suspected of arson – human impact behind many major wildfires

Many forest and land fires are caused by people – through carelessness or intentional arson. During this summer’s European fires, a very large number of people have been arrested on suspicion of starting fires, something Swedish Radio fails to mention.

Climate and cause of ignition are therefore two different issues – weather conditions can influence fire risk and fire development, while the ignition itself is human-caused. This distinction is easily lost when wildfires are routinely listed alongside heatwaves and climate change.

A Less Sensational Research Result

What remains is the robust main point – extreme heat can affect the economy. Agriculture suffers from drought, transport can be disrupted when rivers have low water, power plants may face cooling problems, and people work less efficiently when the workplace gets too hot.

Humanity probably knew the last point before the concept of GDP was even invented. The more interesting scientific question is therefore not whether heat impacts productivity, but how much, how reliably this can be translated into hundreds of billions of euros, and how much of the effect can be avoided through things like air conditioning, changed working hours, and other adaptations.

Triodos Bank makes an attempt to put a price tag on this and arrives at about 180 billion euros for the EU in 2026. This is a striking estimate.

But perhaps the Science Desk could have devoted a little more scientific curiosity to how the figure was calculated – and a little less to telling listeners that it’s tough to work when it’s hot.