Pope Francis has run into more storms than one during a visit to the US that has turned out to be surprisingly political.

His canonisation of Junipero Serra, an 18th century missionary to Native Americans in California, was bitterly resented by the descendants of the said Native Americans, who see the new saint as part of an oppressive, if not actually genocidal, colonial system.

While conversatives have lapped up his support for the family and opposition to homosexuality and abortion, they have had a metaphorical choking fit regarding his call for action on climate change.

For politicians and conservative Catholics alike, climate change has become the litmus test for liberalism. The Catholic website Rorate Caeli tweeted after Francis' White House speech: "Not sure if that was a speech by the head of the Catholic Church or Al Gore..."

Republican Congresswoman Marsha Blackburn, the second-highest ranking member on the House energy committee, has said the jury is out on global warming and that the Pope was wrong. Another Republican Congressman, Paul Gosar, is going to boycott the Pontiff's address to Congress today, while Senator John Barrasso, who rejects mainstream climate science, told Politico: "I'll certainly listen respectfully, but I don't think that his speech is going to change my mind on it."

The Republican presidential candidates are notably sceptical about climate change, and far more so than Democrats, with only two – Lindsey Graham and Bobby Jindal – making specific proposals to counter it.

But what drives conservative opposition to the very idea that climate change is human-induced?

What's clear is that the answers don't lie in the science. The data is available to everyone of whatever political colour. There's something else going on, and it has much more to do with worldview and ideology than it does with hard facts.

1. Conservatives have a greater tendency to be anti-science. In many cases this has a religious foundation. Marsha Blackburn, for instance, has said that she does not believe in evolution and that the world is only around 6,000 years old. Presidential candidate Ben Carson – a highly respected brain surgeon – has said that climate change debate is "irrelevant" because global temperature change is cyclical. Carson has also said that Charles Darwin was inspired by Satan and that evolution and the Big Bang are "ridiculous" theories. His case is particularly interesting because of his medical background: he appears to be able to compartmentalise his analytical skills, so that he applies them to areas which don't threaten his religious worldview but not to those that do.

2. Conservatives have an inbuilt suspicion of 'big Government' and a commitment to libertarianism. That means that they are constitutionally anti-authoritarian. So for many conservatives, the fact that the vast majority of scientists believe that climate change is largely caused by human activity generates an automatic push-back – if everyone believes it, they must be wrong. Dissent from the majority view is seen as laudable just because it's dissent, whether there are any grounds for it or not. The scientific consensus is put down to a socialist conspiracy. Research by Bristol University academics has found that up to 40 per cent of those who are sceptical of human-induced global warming talk about 'scams' and allege that data has been faked.

3. A key tenet of conservatives is a commitment to the free market and a belief that enterprise and industry are solutions to the world's problems. The less regulation and government interference there can be, the better. So conservatives have bitterly resisted moves to limit exploration for oil and minerals in the Arctic, arguing that the world's need for energy should trump the need to protect the environment. The Pope's calls to limit economic growth, to make the profit motive serve human wellbeing, to make cities meet the needs of those who live in them rather than those who make money out of them – though they're thoroughly in line with the Catholic social teaching developed since 1891 – are anathema to those who believe that the market can do anything and that attempts to control it are fundamentally unAmerican. If they are to believe that it's the unchecked human exploitation of the planet since the Industrial Revolution that's leading to catastrophic climate change, it's a challenge to their whole worldview, shaking their moral and philosophical foundations. It's no wonder that they meet the suggestion with outraged denial.

4. The people who find it easier to go along with the science of climate change are their natural enemies. Both Republican and Democratic parties in the US are right-wing, in UK terms. But far more Democrats than Republicans believe in human-induced climate change, because they are less wedded to the idea that capitalism is an unqualified good. They also see climate change on the agenda of despised organisations like the UN, European governments characterised as liberal and a raft of special interest environmental groups. The idea of making common cause with people like this is very difficult. So human-induced climate change becomes one of a cluster of ideas that conservatives lump together as 'dodgy' – like socialism, the Iran nuclear deal, rapprochement with Cuba and Islam.  

Such is the polarisation in US politics at present that it's very difficult to see any consensus growing. This is an alarming scenario. Republicans already control both Houses of Congress. In theory, the progress on climate change that has been so painfully achieved under the Obama presidency could be undone at a stroke with the election of a sceptical Republican president.

In practice, there is a good deal of inertia in government which means that this is unlikely to happen immediately. However, the country's scientific community is unlikely to be sanguine about the election of politicians who regard their work as fantasy and feel free to ignore it.

It's hard not to feel that America's climate change deniers need to be challenged to come clean about their real motivations. The facts about climate change are just facts. They are only incidentally a challenge to a particular political and moral worldview. It's time for some honesty – and time for conservatives to put some hard thought into reconciling the facts with their philosophy.

Follow @RevMarkWoods on Twitter.