About Tom Crowther

Thomas Crowther is an ecologist studying the connections between biodiversity and climate change. He is a professor in the Department of Environmental Systems Science at ETH Zurich, chair of the advisory council for the United Nations Decade on Ecosystem Restoration, and founder of Restor, an online platform for the global restoration movement. In 2021, the World Economic Forum named him a Young Global Leader for his work on the protection and restoration of biodiversity.


After completing his PhD at Cardiff University, Crowther received a postdoctoral fellowship from the Yale Climate and Energy Institute. In 2015, he was awarded a Marie Curie fellowship at the Netherlands Institute of Ecology (NIOO) at Wageningen University to research the impact of carbon cycle feedbacks on climate change.

Crowther began his professorship at ETH Zurich in 2017, where he started Crowther Lab, an interdisciplinary group of scientists exploring how global-scale ecological systems interact to regulate the climate and collecting data to inform best practices for ecosystem-specific restoration efforts.

Landmark Research

Crowther’s landmark post-doctoral research, published in 2015, transformed the understanding of the world’s tree cover, estimating the global number of trees at approximately 3.04 trillion. The research also estimated that the total number of trees has declined by almost half since the agricultural revolution 12,000 years ago, and the Earth continues to lose around 10 billion trees each year.

In 2019, his paper on the global tree restoration potential attracted wide-spread attention for estimating that there are 0.9 billion hectares of land outside of urban and agricultural land where trees would naturally be able to grow. The study suggested that if this land could be protected, there would be room for one trillion more trees, which could capture up to a third of the excess atmospheric carbon to date.

Supporting Restoration

The study inspired the World Economic Forum to announce its Trillion Trees initiative, 1T.org, which aims to conserve and restore one trillion trees globally within the decade. Crowther serves on the advisory board of 1T.org.

Crowther’s large-scale ecological research led to the development of Restor, a science-based open data platform that offers ecological insights, transparency, and connectivity to conservation and restoration projects world-wide. In 2021, Restor launched as an independent not-for-profit organisation and was selected as a finalist for the Royal Foundation’s Earthshot Prize. The platform connects and supports more than 76,000 conservation and restoration projects worldwide.

Crowther’s work continues to deepen public and scientific understanding of how nature-based solutions and the protection of biodiversity can help limit climate change and improve human well-being.

Get in touch with Prof. Crowther.