Summary

• Feedback effects occur when a change triggers an effect that reinforces the initial change, leading to dangerous tipping points.
• A feedback that increases an initial warming is a ‘positive feedback.’
• A feedback that reduces an initial warming is a ‘negative feedback’.
• Once certain tipping points are reached, the feedback effect becomes self-sustaining. That is, it can’t be reversed. 
• Multiple feedback effects are now underway. For example, a positive feedback in global warming is the increase in the amount of water vapour in the atmosphere, leading to further warming for reasons explained here. Similarly:

Wildfires releases reactive gases that reduce the atmosphere’s oxidation capacity, thereby increasing methane concentrations and amplifying warming. – Chen et al 2026

• Because Earth’s systems are linked, a positive feedback from one, such as declining sea ice, leads to a cascading series of positive feedbacks. The following section describes how this leads to a reduced albedo effect, keeping more heat in the atmosphere, while an increasing number and intensity of raging wildfires compounds this leading to other positive feedbacks across the planet (Fig. 4).