Climate extremes become psychologically
A new study shows people stop finding unprecedented temperatures remarkable after repeated exposure, a phenomenon known as shifting baseline syndrome.
People are becoming desensitised to the word 'unprecedented' as it is used with increasing frequency to describe climate extremes, according to science writer Helen Pilcher. A study analysing over 2 billion weather-related social media posts reveals that while extreme temperatures become less remarkable with repeated exposure, the negative feelings they cause do not diminish.
Frances Moore from the University of California, Davis, led the research. The team found that people's judgment of what is remarkable changes based on recent experience, not historical records. This means a temperature can be historically unprecedented but psychologically precedented. Our baseline for what is normal is constantly shifting.
Shifting baseline syndrome
Ecologists call this phenomenon 'shifting baseline syndrome'. It was first described by Daniel Pauly in the context of fisheries, where successive generations of scientists accepted increasingly depleted fish stocks as normal. The concept now applies broadly to environmental issues, including biodiversity loss, pollution, and the climate crisis. Our collective memory of past conditions erodes, resetting our expectations.
Moore's study contained a critical finding. The data showed that the unpleasantness associated with extreme heat persists even as the sense of its remarkability fades. We may stop being surprised by record-breaking temperatures, but we do not necessarily become tolerant of them. This disconnect is a key feature of how we perceive a changing climate.
The danger of normalisation
The danger lies in the normalisation of extremes. If unprecedented heat starts to feel familiar, we may fail to recognise just how extraordinary it is. What was once remarkable becomes just another hot summer or another crop failure. As the baseline shifts, so does our sense of urgency about what needs to be fixed. If the rising temperature feels normal, we are less likely to demand action to turn down the heat.
This process is often compared to the parable of the boiling frog. However, Pilcher notes the parable is scientifically inaccurate. A healthy frog would not sit idly in slowly warming water; it would jump out when the heat became intolerable. The question for humanity is what it will take for us to respond with similar decisiveness.
Retaining the meaning of words
One starting point is to be mindful of the language we use. Words like 'awesome' have become semantically bleached through overuse for mundane things. Pilcher argues we must guard against the same fate for 'unprecedented' in climate reporting. The word signifies that we have entered territory humanity has never before experienced. Retaining that historical meaning is key for maintaining an accurate sense of scale and urgency.
The unsettling reality of a heating world may not be that unprecedented weather keeps happening. It is that describing it as 'unprecedented' is beginning to sound perfectly normal.
