Researchers at the University of Calgary said that massive volcanic eruptions had caused the world's biggest extinction.

According to the researchers, massive volcanic eruptions that took place 250 million years ago during the Permian Period burned heavy volumes of coal, produced ash clouds and increased greenhouse gases drastically, which wiped out 95 per cent of life in the seas and 70 per cent of life on land.

It is believed that dinosaurs became extinct around 65 million years ago by the impact of a meteorite, but scientists are yet uncertain on what was the cause of the so-called late Permian extinction.

However, some scientists are of the view that massive volcanic eruptions had led to the largest extinction on Earth.

The new study supports the view. Steve Grasby from the University of Calgary said, "In addition to these volcanoes causing fires through coal, the ash it spewed was highly toxic and was released in the land and water, potentially contributing to the worst extinction event in earth history."

The massive volcanic eruptions had changed Earth's Chemistry radically.

The findings were published on Sunday in Nature Geoscience.