A recent Financial Times Newsletter article by Jana Tauschinski titled What if carbon sinks are not working? (19 October 2025) summarised new data from the World Meteorological Organization (WMO) showing that atmospheric carbon dioxide rose by 3.5 parts per million in 2024, the largest single year increase since records began in 1957. That puts CO₂ levels at 423.9 ppm, or 152 per cent of the pre-industrial concentration.

This sharp rise suggests that the sustained, record-high level of human emissions, which have now plateaued, may be overwhelming the planet’s natural carbon sinks, potentially signaling a dangerous climate feedback loop. Scientists now believe that the planet’s natural carbon sinks, such as forests, soils and oceans, are absorbing less carbon than before. Permafrost in the Arctic is melting and releasing stored methane.  Wildfires, droughts and ocean heatwaves may be weakening nature’s ability to rebalance the system. In simple terms, the planet is losing one of its main safety valves.

Researchers at Exeter University also warn that we may already have crossed the first climate tipping point, with warm water coral reefs suffering mass mortality after years of marine heat stress. The World Weather Attribution group adds that global temperatures are now about 1.3°C higher than before industrialisation, and even if current promises are met, we are on course for around 2.6°C of warming by 2100. That could mean about 57 extra hot days each year on average, and more than 100 in some countries.

These are not abstract numbers. They translate into higher energy bills, disrupted harvests, rising insurance costs and greater migration pressures. They also bring health risks, loss of biodiversity and fragile infrastructure under strain.