Scientist Tim Flannery has proposed a radical solution to climate change which may change the colour of the sky.
But he says it may be necessary, as the “last barrier to climate collapse.”
Professor Flannery says climate change is happening so quickly that mankind may need to pump sulphur into the atmosphere to survive.
Australia’s best-known expert on global warming has updated his climate forecast for the world – and it’s much worse than he thought just three years ago.
He has called for a radical suite of emergency measures to be put in place.
The gas sulphur could be inserted into the earth’s stratosphere to keep out the sun’s rays and slow global warming, a process called global dimming.
“It would change the colour of the sky,” Prof Flannery told AAP.
“It’s the last resort that we have, it’s the last barrier to a climate collapse.
“We need to be ready to start doing it in perhaps five years time if we fail to achieve what we’re trying to achieve.”
Prof Flannery, the 2007 Australian of the Year, said the sulphur could be dispersed above the earth’s surface by adding it to jet fuel.
He conceded there were risks to global dimming via sulphur.
“The consequences of doing that are unknown.”