Who is responsible for limiting global warming to 1.5°?

Even if industry rapidly becomes more sustainable, households will still need to change their lifestyles to meet climate targets. Industrial ecologist Stephanie Cap warns that households cannot do this alone: Businesses and governments must create the conditions to make these changes possible. Cap defends her dissertation titled “Everything Must Change: 1.5°C decarbonisation scenarios across industries and households” on Oct. 1.

Using scientific models, Cap has developed scenarios for 2030 and 2050, mapping out what is needed to reduce greenhouse gas emissions and limit global warming to 1.5°, the threshold below which climate change remains harmful but still manageable. One thing is certain, she says: “Making industry more sustainable is not enough on its own to stay within 1.5°, and neither is making households more sustainable. We really need both.”

What can we do?

For her research, Cap analyzed five European countries: Germany, Spain, Latvia, Hungary and Sweden. Each has a different starting point in terms of renewable energy infrastructure, dependence on fossil fuels, household income and, to some extent, policy. Using scenario models based on the EXIOBASE database, she mapped the carbon footprint of households. “If you buy vegetables, a laptop or electricity, the model looks at all the production factors involved in producing that product. For one euro’s worth of food products or train travel, for example, I can calculate how many greenhouse gases were emitted in the process.”

With these models, Cap set out to answer a key question: What happens to greenhouse gas emissions if households change their consumption patterns? To find out, she developed various “portfolios” of measures and changes. Reducing the use of cars with internal combustion engines, phasing out fossil-fuel heating and switching to plant-based diets consistently delivered the largest emissions reductions. Her scenarios also assumed that industry would become far more sustainable.

So, is the 1.5° target achievable? In the scenarios for 2030, it is theoretically possible, but only if a large share of the population adopts a wide range of lifestyle changes. In countries with relatively high emissions, at least 87% of the population would need to take part; in Spain and Hungary, that share is lower, at around 50% to 60%. The picture for 2050 is even more challenging: Germany, Latvia and Sweden fail to meet the 1.5° target. Only Spain and Hungary can theoretically achieve it, and only if high-impact measures are implemented almost in full.

Cap notes that the exploratory scenarios are based on a 2015 baseline and on decarbonization pathways developed several years ago. But she says this does not diminish the implications for the scale of lifestyle changes and decarbonization needed.

Conditions for change

A figure as high as 87% immediately raises the question of whether people are willing and able to make these changes. Cap stresses that this is not simply a matter of willingness. Relying less on cars, for instance, is difficult without good public transportation or working hours that make it a realistic option. Circumstances play an equally important role in other choices. According to Cap, it is not only households that need to change: Businesses and governments must also create the conditions that make such choices possible.

A message for Brussels

Cap concludes that, even with rapid industrial decarbonization, major changes in household consumption are still needed. With these findings, she hopes to renew the sense of urgency among EU policymakers. In short, there needs to be a stronger push for emission-free heating, transportation and individual lifestyle changes.

She sees a powerful message in what might seem like discouraging results: “I understand that it can feel overwhelming when you look at the gap between where we are now and where we need to be. But individual changes are an essential part of staying below 1.5°. I hope people feel empowered to make changes, knowing that they really can make a difference.”

Who’s behind this story?

Lisa Lock

BA art history, MA material culture. Former museum editor, paramedic, and transplant coordinator. Editing for Science X since 2021.

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Andrew Zinin

Master’s in physics with research experience. Long-time science news enthusiast. Plays key role in Science X’s editorial success.

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