Six Degrees: Our Future on a Hotter Planet

A Book by Mark Lynas

In his book "Six Degrees: Our Future on a Hotter Planet," Mark Lynas takes readers on a journey through the potential impacts of climate change, exploring the consequences of a world that is 1, 2, 3, 4, 5, and 6 degrees Celsius warmer than pre-industrial levels.

1 Degree Celsius: A World on the Brink

At 1 degree Celsius of warming, the world is already experiencing the effects of climate change, including rising sea levels, melting glaciers, and more extreme weather events. Lynas argues that even this level of warming is having a significant impact on ecosystems and human societies, and that we are already seeing the early signs of the climate crisis.

2 Degrees Celsius: The Threshold of Danger

At 2 degrees Celsius of warming, the impacts of climate change become even more severe. Coral reefs, which are essential for marine biodiversity, are projected to decline by 90%. Heat waves and droughts become more frequent and intense, leading to widespread crop failures and water shortages. Lynas argues that 2 degrees Celsius is a critical threshold, beyond which the risks of climate change become catastrophic.

3 Degrees Celsius: The Uninhabitable Earth

At 3 degrees Celsius of warming, the world becomes a very different place. Sea levels rise by several meters, inundating coastal cities and displacing millions of people. The Amazon rainforest, a vital carbon sink, could collapse, releasing vast amounts of greenhouse gases into the atmosphere. Lynas argues that 3 degrees Celsius is a point of no return, beyond which the Earth's climate system could spiral out of control.

4 Degrees Celsius: The End of Civilization?

At 4 degrees Celsius of warming, the impacts of climate change become truly apocalyptic. Large parts of the world become uninhabitable, leading to mass migrations and social unrest. Food production collapses, leading to widespread famine. Lynas argues that 4 degrees Celsius is a level of warming that could lead to the end of human civilization as we know it.

5 Degrees Celsius: The Hothouse Earth

At 5 degrees Celsius of warming, the Earth enters a hothouse state, where the climate system is fundamentally altered. The oceans become too warm for most marine life, and the land surface becomes too hot for many plants to survive. Lynas argues that 5 degrees Celsius is a level of warming that could make the Earth uninhabitable for humans.

6 Degrees Celsius: The Last Chance

At 6 degrees Celsius of warming, the Earth's climate system is completely destabilized. The polar ice caps melt entirely, sea levels rise by tens of meters, and the Earth's temperature becomes too hot for humans to survive. Lynas argues that 6 degrees Celsius is a level of warming that would lead to the extinction of the human race.

Conclusion

"Six Degrees: Our Future on a Hotter Planet" is a powerful and urgent book that provides a comprehensive overview of the potential impacts of climate change. Lynas's writing is clear, engaging, and accessible, and he does an excellent job of presenting the scientific evidence in a way that is both informative and compelling. This book is a must-read for anyone who wants to understand the risks of climate change and the urgent need for action.