This Science Café explores how climate change is reshaping patterns of human migration.

For thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. As Marten Scheffer shows, this distribution likely reflects a human temperature niche related to fundamental constraints. Depending on scenarios of population growth and warming, over the coming 50 years, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 years. A complementary analysis reveals that, in the absence of climate mitigation or migration, a substantial portion of humanity would be exposed to mean annual temperatures warmer than those in nearly any place today.

Against this planetary backdrop, Ingrid Boas poses that climate impacts rarely translate into simple or uniform patterns of migration. The research of Prof. Boas seeks to move beyond a narrow understanding of climate migration. The impacts of climate change often affect human lives and human mobility in a more complex, political, and diverse way than we tend to assume and imagine. A just approach to climate governance requires us to take the politics and practice of climate change and human mobility seriously, to avoid generalisation and the imposition of frames and policies. In taking this approach, Professor Boas examines how different populations experience and govern climate mobilities in order to contribute to equitable policies prioritising the needs and interests of those most affected.

In the discussion, we may examine how these biophysical constraints and social realities interact—and how the tensions they create may unfold, be governed, or be released in the decades ahead.

Ingrid Boas is a Professor at the Environmental Policy Group of Wageningen University & Research. She works on climate change and human im/mobility relations since 2007. She brought forward a collective research agenda on climate mobilities, which translated into an international collaborative Environmental & Climate Mobilities Network (ECMN). Her research is currently informed by two research programmes on climate mobilities funded through the Dutch Scientific Organisation and the Belmont Forum, focussed on West Africa, the Pacific, and the Bengal region.

Marten Scheffer is a leading Dutch ecologist and emeritus professor at Wageningen University & Research. He is internationally renowned for his pioneering work on ecological and complex systems, particularly the theory of tipping points—abrupt shifts that can occur when systems lose resilience. His research has profoundly influenced thinking across ecology, climate science, economics, and social systems. Beyond academia, he is an influential public intellectual and science communicator. He received the Spinoza Prize in 2009 and became a member of the Royal Netherlands Academy of Arts and Sciences in 2021. In 2025 he retired, and his book The Tipping Point (De Kanteling) was published in Dutch; the English edition, Tipping Out of Trouble, appears in April 2026.