For centuries, volcanologists have been predicting when volcanoes will erupt. Forecasting when a volcano might blow has been pretty unreliable. However, a study from NASA scientists and the Smithsonian Institution say they are a step closer to providing more accurate forecasts. They used images from space to detect changes in the colour of leaves near volcanoes. The study showed that an increase in carbon dioxide levels emitted by two active volcanoes in Costa Rica had an impact on the colour of foliage. Trees in the surrounding areas became greener.

Current methods of predicting volcanic explosions include checking seismic activity, changes in ground height, and carbon dioxide emissions. NASA said its new method of monitoring the colour of foliage from space could give better predictions. The science behind this is easy to understand. As magma moves upwards through Earth's crust, it releases carbon dioxide. Trees absorb this and their leaves become greener. The LiveScience website said: "These signs can help to protect communities against the worst effects of volcanic blasts, including lava flows…and toxic gas clouds."