Let's rank the threats to human survival

May 21, 2025

In Bob Douglas’ article, he reminds us of the 10 threats to human survival as listed by Julian Cribb in his 2023 book, How to fix a broken planet.

It is hard not to stave off despair when faced with such a long list, so I chose the three that are most likely to keep me awake at night. They are: climate change; a threat to the world’s food supply; and growth in the human population.

The question is: will we be able to feed everyone in the face of climate change? We have 8.2 billion people in the world, a figure that still grows by 70 million a year. The rate of sea level rise has doubled over 30 years to 4.5mm/yr in 2023. People in low-lying islands in the Pacific, such as Kiribati, are already experiencing salt-water incursions into their gardens, killing breadfruit and other trees that have sustained them.

Likewise in deltas such as the Mekong. Climate change will improve yields in some crops like wheat and rice and lower others such as maize, though changes to the seasons may lead to crop loss and famine. There is no room for complacency.