So that’s how the world’s going to die, is it, because straight men are scared people might think they are gay? According to new research by Penn State University, men may be avoiding environmentally friendly activities because they fear that anyone who catches them recycling or carrying a reusable shopping bag may think they’re seeking romantic trysts with other guys. So when men are scrabbling around in the sun-scorched dirt for food, or swimming their way through Covent Garden, or sheltering their family from Mad Max-style societal breakdown, they can at least comfort themselves that their precious heterosexuality remains intact.

Of course, climate emergency won’t be solved purely by more recycling or fewer plastic bags – but the study is revealing. Both men and women see caring about the environment as “feminine”; and men associate feminine behaviour by men with being gay.

Homophobia can harm straight men – driving them into destructive behaviour

Here is a little-discussed feature of homophobia. We know that its principal victims are, of course, LGBTQ people: from the lifelong impact on mental health caused by abuse and rejection, to the constant menace of verbal and physical assault. But homophobia can harm straight men, too – driving them into destructive behaviour that impacts on the people around them.

From a very young age, boys are taught that real men get into fights, say demeaning things about girls and women, show extraordinary athletic prowess, avoid looking studious, don’t do anything to display supposed emotional “weakness” and prioritise competition over cooperation. It is an invisible authoritarian regime, but one – like any dictatorship – enforced through intimidation and violence. Perceived dissidents – those who either inadvertently or intentionally diverge from these patterns of behaviour – are liable to suffer everything from being cussed in a school corridor to being thumped, and worse.

The abuse will begin with calling the victim a “girl” or a “poof”, and the message is the same: you have deviated from true masculinity and you must be punished for it. This is gender policing: homophobia is the border guard of patriarchy.

This isn’t to be self-righteous – as a gay adult I can, to my own shame, recall engaging in homophobic abuse as a child. As Jean-Paul Sartre put it: “Half victims, half accomplices, like everyone else.” What this formative experience does is install an internal policeman in the heads of men, whether they are straight or LGBTQ, which barks at them “don’t do this or you will look gay”. Among queer men, this internalised homophobia can mean failing to correct a stranger who asks about your girlfriend because you’re too embarrassed to say. But it also leads dispiriting numbers to reject camp men, often in hurtful and demeaning ways; to say they only fancy “real men”; to suggest that such displays of feminine behaviour attract homophobia, in depressing displays of victim blaming. Some put “straight-acting guys only” in their dating app profiles (sorry to break this to you, but no man looks “straight-acting” when having sex with another guy). It causes shame and self-loathing, which drive mental distress, and can lead to damaging self-medication in the form of drug and alcohol abuse.

Among straight men, there’s a simple test for the internal policeman: even many men who avowedly back LGBTQ rights will show offence if someone mistakenly thinks they’re gay, and demand to know what behaviour of theirs led to such a conclusion.

You saw me covered in blood on a bus. But do you get outraged about all homophobia? | Chris Read more

It can lead to grown men refusing to back down or walk away when an argument gets dangerously out of control. It can mean competing with male friends to say the most degrading things about women – normalising a culture that leads to women and girls being assaulted and raped. And it can also mean that men who suffer depression and anxiety feel it’s unmanly – or indeed gay – to talk about their feelings. Suicide is the biggest single cause of death for men aged under 45 in Britain: countless others suffer silently. Here are men caught up in the barbed wire lining the frontiers of unreconstructed masculinity.

It’s clear that the success of the LGBTQ rights campaign would free straight men, too. Already, combined with feminism, it has changed what it is to be a man. Men talk more about their feelings than they once did, have more female or gay friends, and spend more time helping to raise children – albeit still not as much as they should. When patriarchy finally lands on history’s scrapheap, all – men, women, non-binary – will be free to be themselves, unpoliced. In defiance of the protesters outside school gates, affronted that children should be taught that some kids have two mums, our education should do even more to challenge oppressive norms. Who knows: one day men might even recycle rubbish without caring that someone may think they want to elope with another guy.

• Owen Jones is a Guardian columnist