Top climate scientists have admitted they failed to predict the intensity of flooding in Germany and the North American heat dome.
They have correctly warned for decades that a warming climate would soon bring greater rainfall and more damaging heat waves.
But they say their computers are not powerful enough to accurately project the severity of those extremes.
They want governments to spend more on a shared climate supercomputer.
Computers are essential to weather forecasting and climate change, and computing will underpin the new climate science "bible" from the Intergovernmental Panel on Climate Change (IPCC) next month.
