What frightens me about the climate crisis is we don’t know how bad things really are

‘What is the use of a net zero policy if it relies in part on planting trees that may crackle in wildfire?’ Firefighters tackle wildfires on the Greek island of Rhodes, 25 July 2023. Photograph: Graeme Robertson/The Guardian

Over the past few decades, climate scientists have made huge strides in understanding the future climate. But after recent weeks of extreme heat and devastating floods it’s clear that, although climate models have provided good information about overall rising temperatures, they can’t be sure what level of destruction each notch on the thermometer will bring.

Climate modelling is extremely complex, but its fundamentals rely on basic physics – X tonnes of emissions will bring Y increase in temperature, with some error bars. Supercomputers have been able to factor in shifts in land use that will change the reflectivity of the Earth’s surface. Improved temperature records helped verify their findings.