Former Australian prime minister Tony Abbott has suggested climate change is “probably doing good” in a speech in London in which he likened policies to combat it to “primitive people once killing goats to appease the volcano gods” .

Abbott delivered the annual lecture to the London-based Global Warming Policy Foundation (GWPF), a climate sceptic thinktank on Monday evening. The Guardian and several other media outlets were blocked from attending the event but a copy of the speech was later circulated.

Abbott told the group the ostracisation of those who did not accept climate science was “the spirit of the Inquisition, the thought-police down the ages”. He also reprised his 2009 assertion that the “so-called settled science of climate change” was “absolute crap”.

Measures to deal with climate change, which Abbott said would damage the economy, were likened to “primitive people once killing goats to appease the volcano gods”.

“At least so far,” he said, “it’s climate change policy that’s doing harm. Climate change itself is probably doing good; or at least, more good than harm.”

“There’s the evidence that higher concentrations of carbon dioxide – which is a plant food after all – are actually greening the planet and helping to lift agricultural yields. In most countries, far more people die in cold snaps than in heatwaves, so a gradual lift in global temperatures, especially if it’s accompanied by more prosperity and more capacity to adapt to change, might even be beneficial.”

When he was prime minister, Abbott said he took the issue of climate change “very seriously”. But since he was deposed as prime minister by his Liberal party colleague and bête noire Malcolm Turnbull in 2015, Abbott has returned to many hardline views he had tempered as leader.

He told the GWPF Australia needed “evidence-based policy rather than policy-based evidence” and took aim at a 2013 study that showed that 97% of scientists agree humans are driving climate change, “as if scientific truth is determined by votes rather than facts”.