Disasters associated with natural hazards are constantly in the headlines. Some involve predictable human-made factors, such as the catastrophic floods in Derna, Libya, in September, which were caused by the collapse of two dams after torrential rains. Others are unexpected, such as the eruption of volcano Hunga Tonga-Hunga Ha'apai in Tonga in January 2022, with a plume that reached a height of 57 kilometres 1 . That eruption caused a Pacific-wide tsunami and cut the country's undersea communication cables, shutting down national and international telephone and Internet traffic 2 .In all cases, what turns natural hazards into disasters is their damaging effects on communities and ecosystems. These can often be avoided, or at least attenuated, through accurate forecasting of an event, advance warning to the relevant populations and well-prepared response plans.In March 2022, the United Nations secretary general, António Guterres, announced an Early Warnings for All initiative backed by a US$3.1-billion investment over 5 years. The aim, he stated, is to ensure "everyone on Earth is protected from hazardous weather, water, or climate events through life-saving early warning systems by the end of 2027". This commitment is necessary, bold and ambitious. Here, we argue that it is also doomed to fail From floods to wildfires, and tsunamis to volcanic eruptions, early-warning systems can stop natural hazards becoming human disasters. But more joined-up thinking is urgently needed.