DR KARL Kruszelnicki might be known for his cheery disposition and colourful t-shirts but underneath he's worried.
In Ipswich signing copies of his new book 50 Shades of Grey Matter, the celebrity scientist told the QT recent journal articles had him worried about the planet's future.
"Over the last couple of months we've had all this scary stuff come through the scientific literature," he said.
"Number one in the Arctic. We've lost 80% of the volume of the summer ice since 1980. Not eight, but eight-zero.
"And if it keeps on dropping at the same rate as it has the last few years as it has the last five years there will be no ice in the Arctic in five years in summer.
"Number two, the permafrost is melting. And if you look at a map of the northern hemisphere and you think 'there's all this continent and there's a little bit of permafrost' but if you look from the top the permafrost makes up one quarter of all the land mass in the northern hemisphere.
"As it gives off the carbon dioxide and methane, and molecule for molecule methane is a 100 times worse than carbon dioxide for global warming, it warms up the world a bit.
"That defrosts more permafrost which gives off more greenhouse gases which defrosts more permafrost."
The well-known guest host on a number of ABC radio stations and TV shows wasn't all doom and gloom though, telling the QT he was preparing some scientific facts to be told around the Kruszelnicki family Christmas table.
"None of my kids are in science," he said.
"It's like the cobbler children have no shoes. So if I tell them science it has to be really interesting.
"Like if you lean to the left you're more likely to underestimate the height of a building than if you stand straight.
"(But if you lean to the right) it doesn't go up. Funny. I don't get that one."
His signing at Angus and Robertson Riverlink on Saturday was the final stop on a tour of bookshops across the country.
Ipswich fans lined up outside the store throughout the day getting signed copies of his latest book and asking their scientific questions.