Gently limiting “luxury” demand from the 20% of European consumers who use the most energy saves seven times the amount of planet-heating gases that would be emitted in meeting the basic needs of the 20% who use the least energy, researchers have found. The study, which modelled the effect of narrowing the gaps in energy use between households within 27 European countries, found capping demand from the top fifth, even at a fairly high level, cut greenhouse gas pollution from energy consumption by 9.7%, while raising demand from people in the bottom fifth who also live in poverty to a fairly low level increases emissions by just 1.4%. “We have to start tackling luxury energy use to stay within an equitable carbon budget for the globe,” said Milena Buchs, a professor of sustainable welfare at the University of Leeds and the lead author of the study, published on Monday in the journal Nature Energy, “but also to actually have the energy resources to enable people in fuel poverty to slightly increase their energy use and meet their needs.” To stop the planet heating beyond the levels agreed to by world leaders, rich countries must quickly clean up their supply of energy and cut demand for it. The Intergovernmental Panel on Climate Change (IPCC) found in its latest review of the science that demand-side strategies can slash global emissions 40-70% by 2050 compared with business as usual. Many solutions would need help from governments to become cheap enough for everyone. But some of the most polluting lifestyle choices include flying abroad on holiday, driving large cars that use a lot of fuel and living in big houses with bad insulation. Buchs and her colleagues sorted people in 27 European countries – the EU plus the UK and minus Austria – by how much energy they used. Then they shrank the “consumption corridor” between the most lavish and frugal within each country. In an invented country of 100 people, where the first person uses the least energy and the 100th uses the most, the scientists lowered the energy demand of the 81st-100th people to the level of the 80th. They then took the first to the 19th people and increased their energy demand to the level of the 20th. Across Europe, they found capping luxury demand cut household emissions from energy by 11.4%, from transport by 16.8% and in total by 9.7%. Meeting the basic needs of those in poverty pushed emissions up by 1.2 percentage points from home energy use, 0.9 percentage points from transport and 1.4 percentage points overall. “The study confirms that energy demand reductions can contribute significantly to climate change mitigation, even as poorer households are lifted out of energy poverty,” said Felix Creutzig, an IPCC author and professor of sustainability economics at the Technical University of Berlin, who was not involved in the study. “High-income, high-education households have more scope and also more capacity in reducing their greenhouse gas emissions – and also carry more responsibility.” Europe has cut its greenhouse gas emissions about 1.4% each year over the past three decades. Scientists expect the rate to rise as clean technologies grow cheaper and more common but warn progress is too slow to meet climate goals if demand for energy stays high. If the remaining carbon budget to stop the planet heating to 1.5C above pre-industrial levels were split equally between everyone on Earth, the study found, Europe would need to cut emissions by 10% a year. If the budget were shrunk to reflect Europe’s historical responsibility for having dirtied the atmosphere, the required emission cuts would soar to 24% a year. The researchers found that capping energy demand from those at the top, even while helping those at the bottom, makes both targets easier to reach. The yearly cuts needed fell to 8.8% for the bigger carbon budget and to 22% for the smaller one. “The results need to be seen in context: emission reduction goals will still be, in majority, achieved by technological change,” said Creutzig. “Nonetheless, the required rate of technological change is so high that energy-demand reduction would provide crucial support for reaching the climate goals.” Studies have shown the global rich – which includes middle-class people in rich countries – play a disproportionate role in heating the planet. In 2015, the top 1% of earners emitted twice as much carbon dioxide as the bottom 50%, according to estimates from the Stockholm Environment Institute and Oxfam. Rich people have more agency to cut their emissions and those of others. A commentary in Nature Energy argued in 2021 that this covered not just how they shop, which the authors stressed was a powerful lever, but also how they act as citizens, investors, role models and workers. The main issue was whether the changes needed to equitably reduce energy use were realistic, said Kristian Nielsen, an assistant professor at Copenhagen Business School and lead author of the study. “Policies targeting high-energy consumers might become feasible with large-scale public mobilisation and political pressure,” he said.