Older Australians are much less likely to believe in anthropogenic climate change, with over-55s the only Australians to reject climate science, polling from Essential Research finds.

Some 56% of voters believe climate change is real and caused by humans, the highest level recorded since Essential began asking about climate change belief in November 2009; 34% of voters believe fluctuations in the earth’s climate are natural, the lowest level since the 34% recorded in 2009. Liberal voters also reject climate science, 51% to 39%, but that’s a big shift from January, when they split 61%-29%.

People over 55 in particular are very different to the rest of Australia. Only 42% of over-55s believe climate change is caused by humans, while 52% believe it’s natural. That compares to 60% of people under 55 who believe in anthropogenic climate change, and only 28% who think it’s natural. In fact, Essential finds a direct link between climate denialism and age, producing the result that those who will never see the worst effects of climate change are the greatest political impediment to action to address it, while younger people understand the costs they will face as a consequence of our inaction.

However, support for Environment Minister Greg Hunt’s shambolic “Direct Action” plan, which remains unclear six months after the government was elected, has fallen to just 12%, down 3 points from October last year. The proportion of voters who want to keep the carbon price is up 2 points to 17%, while 22% support the transition from a carbon price to an emission trading scheme.

It is Liberal voters who have turned their backs on Hunt’s policy, given Labor and Greens voters were entirely hostile to it; support among Liberal voters for Hunt’s policy of picking polluters to hand billions of dollars in grants to has fallen from 28% to 23%. Some 30% of voters — mostly Liberal voters — don’t want to take any action on climate change.

Meanwhile, Tony Abbott has extended his lead as preferred prime minister over Opposition Leader Bill Shorten to 42%-32%, up from 39%-33% in March. Abbott leads among independent/other voters, 29%-23%. That’s despite Shorten reversing a worrying trend of negative approval ratings — in March his net approval rating was 7 points; it’s now back to 34%-38%. Abbott has basically remained steady, on 41% approval and 47% disapproval, compared to 40%-47% in March.

On voting intention, the two-party preferred outcome remains at 51%-49% to Labor, with the Coalition remaining on 43%, Labor dropping a point to 38%, the Greens steady on 9% and Palmer United on 3%.

Voters’ traditional antipathy to privatisation is also on display: on balance, voters are opposed the privatisation of Medibank Private, opposing it 46% to 25%, although they split on partisan lines, with Coalition voters supporting the sale. But partisanship is much less apparent when it comes to the expected impact on Medibank private premiums: voters are united in expecting that the sale will lead to increases in premiums — 61% expect increases, while only 3% think it might lead to falls in premiums.

They’re also cool on Treasurer Joe Hockey’s proposal to state and territory treasurers that they sell off assets to fund infrastructure investment, opposing it 58% to 25%. Even Coalition voters are unenthusiastic, backing it 44% to 41%.