News Corp’s newspaper the Australian was “absolutely right” to be tough on the Rudd-Gillard Labor government, Rupert Murdoch has said in a television interview on his Sky News channel to mark the 50th anniversary of the national broadsheet.

“The [Labor] government had good intentions in some ways but it didn’t know how to carry them out,” Murdoch said in the interview, aired on Sky News Australia on Sunday. “The NBN was a ridiculous idea, still is.”

The News Corporation owner said the previous Labor government’s blueprint to build the high-speed broadband National Broadband Network had been a waste of money and remained in danger of being overtaken by mobile technology anyway.

“People think I'm talking from my pocket and Foxtel [but] in fact NBN would be great for Foxtel because it would take all those programs into every home.”

Murdoch, who talked to the Australian’s editor-at-large Paul Kelly, had more praise for the Coalition under Tony Abbott, although he said it was too early to be making a judgment on this conservative government.

“My impression is that he is the most admirable, honest, principled man, something we really need in a prime minister, someone we can look up to,” he said. “However, how much does he understand free markets and what should be happening? I don’t know. Only time will tell.”

On the current state of the Australian economy, he said there had been “six years of very mixed government in which the cost of production and the cost of employing people has gone up so much”.

“The car industry is leaving us,” Murdoch said. “All I can see from this distance is the prospect of a lot of unemployment unless we can get small people starting businesses and some bigger industries coming too. We can be the low-cost energy country in the world. We shouldn’t be building windmills and all that rubbish.”

Murdoch said climate change should be approached with great scepticism. “Climate change has been going on as long as the planet is here. And there will always be a little bit of it. At the moment the north pole is melting but the south pole is getting bigger. Things are happening. How much of it are we doing, with emissions and so on? As far as Australia goes? Nothing in the overall picture.”

The worst case scenario was that there would be a 3C rise in temperature over 100 years and only “one of those [degrees] would be manmade”, Murdoch said.

“What it means is if the sea level rises six inches it’s a big deal, the Maldives might disappear, but we can’t mitigate that, we can’t stop it, we just have to stop building vast houses on seashores.

“The world has been changing for thousands and thousands of years, it’s just a lot more complicated today because we are more advanced.”

Internationally, he said he was worried about the high cost of welfare in Europe and medical care and research in the US and was keen to see people working longer than 65 years of age to help pay for the advances in medical care.

“It sounds bad coming from me but I think the welfare state has been overdone particularly in Europe,” Murdoch said.

“With the welfare obligations in Europe you are not going to get growth of more than one or two per cent. We have huge unemployment of young people for many years to come. We’ve got to see this doesn’t happen to us.”

“But I don’t believe we should make it payable not to work. There should always be an incentive to work.”

The interview, conducted by Kelly in New York in May, canvassed the history and ideology of the newspaper as well as current political and economic issues.

Murdoch looked back at the Australian’s political stances over its 50 years, saying he stood by its call in the 1970s to sack the Whitlam government, which caused a strike by the paper’s journalists.

“I think we were right,” he said. “We took the line it might be right or it might be wrong for [opposition leader Malcolm] Fraser to do this but he was entitled to do it under the Constitution. Now that caused a lot of unhappiness amongst journalists who were universally, I would say, for Whitlam although the public was almost universally against him.

“I think the paper has settled down over many years under Chris Mitchell [as editor-in-chief] with a lot of great writers. I think the paper has never been better than it is now and the circulation demonstrates that.”

However, he conceded the print version of the paper may not be around forever. “There could be a time – I’m not saying there will – when it won’t be economical to print.”