Counting on … day 202

11th December 2025

What is a tipping point?

From the Met Office “In the context of climate science, a tipping point refers to a critical threshold in the earth’s system or related processes which, if passed, can cause sudden, dramatic or even irreversible changes to some of the earth’s largest systems, such as the Antarctic ice sheet or the Amazon rainforest.” (1)

And from the Natural History Museum: “Large areas of the world could soon become unrecognisable if global temperatures continue to rise. From the loss of coral reefs to the shutdown of major ocean currents, shifts in Earth’s climate and ecosystems will have untold consequences for billions of people across the world.” (2)

Tim Lennon, head of the Global Systems Institute at Exeter University p, spoke very eloquently on this issue at the recent National Emergency Briefing. You can see a recording here – https://youtu.be/tmd6MDiJmQU?si=goRIfzf8AhiriESi

Tipping points also work in the opposite direction. Just last year the last coal fired power station closed ahead of schedule as policies that encouraged the phasing out of coal reached that critical tipping point. Similar tipping points can also be seen in the cost fall and expansion of wind farms, solars panels and electric vehicles. 

1. https://www.metoffice.gov.uk/blog/2023/what-do-we-mean-by-a-climate-tipping-point
2. https://www.nhm.ac.uk/discover/news/2025/october/we-are-reaching-earths-climate-tipping-points-and-more-are-on-the-way.html