Can we live on our planet without destroying it?

Our consumption patterns affect the environment, that much we know. A clear example is the concentration of carbon dioxide in the atmosphere. It has been rising at an increasingly faster rate since the 1960s, resulting in global warming, along with all its dire consequences. There is a limit to the amount of consumption the Earth can support, and in 2009, scientists defined nine 'planetary boundaries' as indicators of when we have reached that limit. Crossing them may lead to irreversible damage to the Earth's stability and resilience. These planetary boundaries include indicators such as ocean acidification and the global use of fresh water. In 2023, six of these planetary boundaries had already been crossed.

Hubacek has devoted his academic career to studying how humanity is performing in terms of these planetary boundaries, and what needs to change to prevent us from crossing them even further. According to him, 'the basic calculation is: given a certain number of people on the planet and the planetary boundaries, how much can we consume to stay inside these limits?'.

The divide between rich and poor

At the moment, the richest one per cent of the world's population produces 50 times more greenhouse gasses than the four billion people in the bottom 50 per cent. The divide between the rich and the poor on this planet is a common thread in Hubacek's work. He is one of the authors of a paper, published in the journal Nature on 13 November, that describes this issue. Using an extensive dataset covering up to 201 consumption groups across 168 countries, the paper analyses the impact of spending patterns on six key environmental indicators.

The analysis reveals how different consumer behaviours contribute to planetary transgressions, and concludes that if the world's top 20 per cent of consumers shifted their consumption habits toward more sustainable patterns found within their group, they could reduce their environmental impact by 25 to 53 per cent. The study also shows that changing consumption patterns in just the food and services sectors could help bring critical planetary boundaries back within safe limits.

Changing our lifestyle to stay within the boundaries

In previous papers, Hubacek researched specific solutions that could help us balance our lives to better deal with the planetary boundaries. In a study published last August, he showed that if a diet with less red meat and more legumes and nuts was adopted by the richest part of the world, food-driven emissions would fall by 17 per cent, even when the inhabitants of poorer nations increase their meat consumption.

And just last month, Hubacek co-authored a paper describing how the livestock sector is dangerously transgressing several of the planetary boundaries. The paper argues that any measures to counter this negative effect should be 'region-specific': 'Obviously, there will be differences. A plant-based diet is not suitable for traditional Mongolian nomads, who depend on yaks and their milk.'

Hubacek keeps pointing to solutions when he identifies transgressions of planetary boundaries. 'However, we shouldn't focus so much on creating new technical solutions, as there are already so many solutions which we don't implement,' he argues. 'And most governments subsidize bad behaviour.' For example, subsidies for fossil fuels globally are overcompensating for the mitigation effect that we achieve through carbon pricing such as carbon taxes and carbon trading schemes. 'And there are also many inconsistent policies, such as stimulating the use of heat pumps and, at the same time, raising the price of the electricity they use.'

It is possible

What Hubacek shows is that not all hope is lost: humanity can stay within the planetary boundaries. But it seems that there is little political will to tackle issues such as climate change. Hubacek: 'This worries me. And it causes real fear in the younger generation.' Hubacek underlines that his science is not activism-driven. 'I'm doing this work first and foremost because of my academic interest. But I also don't want to waste my time on something that is meaningless. What we need are evidence-based policies.'

Peipei Tian, Honglin Zhong, Xiangjie Chen, Kuishuang Feng, Laixiang Sun, Ning Zhang, Xuan Shao, Yu Liu & Klaus Hubacek: Keeping the global consumption within the planetary boundaries. Nature, 13 November 2024.