For centuries, scientists have been predicting when volcanoes will erupt. This has been pretty unreliable. However, a study from scientists in the USA say they are a step closer to more accurate forecasts. They used images from space to detect changes in the colour of leaves near volcanoes. The scientists found an increase in carbon dioxide levels emitted by two active volcanoes in Costa Rica. This changed the colour of trees in the surrounding areas.

Current methods of predicting eruptions include checking seismic activity and carbon dioxide emissions. Monitoring the colour of leaves from space could give better predictions. The science is easy to understand. As magma moves up through Earth's crust, it releases carbon dioxide. Trees absorb this and their leaves become greener. A website said: "These signs can help to protect communities against the worst effects of volcanic blasts."