Now that the world has experienced its hottest day in history, it is more urgent than ever for natural and social scientists to work together to address the climate crisis.

That is the finding of an international team of researchers who have highlighted the importance of integrating knowledge from natural and social sciences to inform about effective climate change policies and practice. They argue that the concept of tipping points - critical thresholds that, when crossed, lead to large and often irreversible changes in the climate system - can serve as a bridge between these fields of study.

Traditionally, natural scientists have focused on documenting and analysing changes in the natural environment, such as rising global temperatures, altered rainfall patterns, and extreme weather events. More recently, they have questioned whether the changes we are witnessing are reversible and if there is a tipping point at which, no matter how much we curb our greenhouse gas emissions, the environmental changes will be permanent.

However, the research team asserts that these environmental considerations must be accompanied by an exploration of social dynamics, encompassing individual, collective, and societal behaviours. To ensure a sustainable future, it is imperative to comprehend the intricate interaction between environmental and social changes.

The researchers pose critical questions such as:

• Who benefits from and contributes the most to the current trajectory?
• What alternative and desirable scenarios exist, and how can we intentionally work towards them?
• Are there social tipping points that could help us rapidly change our practices, norms, and institutions towards those scenarios?

To show the value of studying social and climate tipping points together, the team focuses on the climate change induced slowdown of the Atlantic Ocean currents, which resulted in the devastating flooding of the Ahr Valley, in Germany. Through this example, they demonstrate how extreme weather events impact local communities and how these communities adapt their ways of life to cope with future extreme events.

The integrated analysis of environmental and social changes allows for an understanding of the complex interaction between climate change and society and enables the assessment of whether our responses benefit everyone, or only a few. Furthermore, it allows for the evaluation of the consequences of human responses at different scales, whether local, national, or international.

The researchers assert that by fostering collaboration between natural and social scientists, the collective capacity to address the climate crisis is enhanced. Their work underscores the critical need for a multidisciplinary approach that combines knowledge from both fields to develop comprehensive solutions and shape sustainable policies for a better future.

The group was led by the Institute of Environmental Science & Technology at the Universitat Autònoma de Barcelona (ICTA-UAB), which includes researchers from other scientific institutions in Australia, Italy, Spain, France, Germany, and Portugal.