Internet pornography has changed the world in secret.

The explosion of sexual content has translated into an industry worth billions of dollars worldwide, yet unlike any other 'market' of that size, it has proved almost impossible to regulate. People's sexual tastes – however broken – have become big business, and the world has seemingly been unable to stabilise this potent mix of sex and money. As a result online pornography is accessed billions of times each week, with almost no ethics applied beyond a widespread agreement that children should not feature. Although as various reports tell us, millions of children are watching it.

Few people openly admit to using pornography, yet the traffic statistics don't lie. Both inside the church and outside it, porn is a part of everyday life, and one which for many people carries with it a sense of deep shame. In the wider culture beyond the church, there is a narrative which suggests porn is perfectly healthy (many therapists are still trained to recommend couples use it to 'spice up' their sex lives), although an increasing amount of neurological work to the contrary is beginning to emerge. Scientists like Dr Bill Struthers, at Wheaton College, Illinois believe pornography is rewiring our brains and seriously damaging our relational health. As part of an article on the subject for Christianity magazine, he told me: "the generation that has been raised on porn is becoming less able to enjoy sexual intimacy, connectedness, and the empowerment that comes in healthy sexual relationships, especially in the context of marriage."

Even if you don't agree with Dr Struthers' assessment – or that of Baroness Kidron, whose 2013 documentary 'In Real Life' presented anecdotal evidence to the same effect – the unregulated, secret world of internet porn is littered with dysfunction. Stories about the mental health of performers, and allegations of links to trafficking abound, but there's one story which is perhaps the most disturbing of all. Since pornography is such big business, usage and search-term statistics are ruthlessly monitored by the industry, in order for the producers to understand what their 'market' wants. And there's one word which has cropped up more than any other in online porn searches for the past two years running, and it's more than a little problematic.

The word? Teen.

A site which receives more than 18 billion visits a year, and which even proudly publishes a 'year in review' document, reports that this search term beat any other on their site in both 2013 and 2014, according to anti-porn campaigners Fight the New Drug. The site is big enough to be indicative of the whole industry, and this ranking is echoed by dedicated statistic sites.

More than any other sexual appetite in the world, pornography users want to see videos of teenagers, or women who look like teenagers, having sex. As a Christian, a youth worker and frankly a human being, I find that deeply disturbing. It seems to me that there are only two possible explanations for this, and both are probably true to some extent.

The first is that teenagers themselves are searching for images of women who look like their peers. That feels 'natural', in the broken world of Internet porn; it seems to me that alongside our outrage at the thought that primary-aged children might be accessing this material, our culture has grudgingly accepted that porn use is just a normal part of adolescent life and development. Jason Royce, Director of the Christian relationship education project Romance Academy, says teenage porn use is far from healthy: "Anecdotal evidence is showing us that pornography is educating our young people about sex and conduct within relationships. When we survey the increasing amounts of violence, rape, and unfaithfulness (and that's not the worst of it) displayed in pornography we should sit up and take note when young people think it's a manual for great sex. It really isn't. As the research catches up, we're learning more every day about the impact of pornography on our young people. This experiment our society has conducted on them will have massive repercussions for their relational and sexual health; that's happened on our watch. Porn lies. It makes promises to the consumer that it can never deliver. The question is, can we point them to a more compelling view of intimacy that outstrips porn?"

The second explanation is much darker, however. It goes like this: porn users of all ages, and it's not a stretch to suggest that most of them are men, are searching for 'teen' videos on pornographic websites because they have developed a sexual attraction to under-18s. People searching for 'teen' are not hoping to find images of 18 and 19 year olds. The word itself is loaded, in a sexual sense, with associations of schoolgirls, cheerleaders and under-age sex.

Here's how Fight the New Drug responds to the statistic: "if millions of people across the globe are constantly searching and viewing porn involving and depicting teens, what do you think that is doing to their sexual tastes and expectations? Is it fair to assume that this massive viewing and demand for the 'teen' genre is making the porn user think that sex with teens is okay? Or that the younger the girl looks, the easier it is to have sex with her?"

We are sexualising childhood in secret, in a way that makes a mockery of our culture's supposed attempts to do the contrary. Arguably, we're grooming a whole planet-ful of people who are learning to fantasise about sex with teenagers. Instead of seeing the emerging generation as the hope for our future, we've become one giant Sodom and Gomorrah mob to them, turning everything good and innocent into yet another sexual object.

Gender equality campaigner Natalie Collins thinks the problem is even broader. "This is about the commodification of childhood and the objectification and degradation of women," she tells me. "The ways pornographies and society degrades women inevitably leads to younger and younger women being sought out to damage. The teen genre of pornographies is not about teenage boys, it's very much about teenage girls. As capitalist structures seek to make money, marketing beauty products and sexualised products to children becomes yet another way of making money. This is true in wider society and within pornographies. The two are linked, in that they are both following that same trajectory; increasing profits by any means possible. I think there is also a normalising aspect; culture has normalised the sexualisation of younger and younger women. Look at Miley Cyrus' shift from Hannah Montana to swinging naked on a wrecking ball..."

All this leaves us in a pretty bleak place. So what can we do? Campaigning for 'teen' web searches to trigger monitoring seems unlikely given the scale we're talking about, and criminalising a significant percentage of the world's population probably isn't the answer. We can and should pray that somehow our governments wrestle some kind of control and regulation over pornography, and we should support organisations like xxxchurch.com which work so hard to educate and liberate porn users. Collins believes we should also be praying that the church would wake up the wider issues: "We must begin praying that God will open our eyes to the reality of the world," she says. "We must be willing to face the hard truths about what is online and across culture. Then as individuals, within our families, churches, workplaces and wider community, we need to be challenging the current understanding about gender, sex and identity."

But there's something else. However shameful it might feel, this is going to be an issue for some of us within the church too. And leaving the wider issue of pornography to one side for a second, let's agree something more pragmatic - to commit never to undertake a search for 'teen' porn, ever. If you're a youth worker and you find yourself doing that, you need to get out of youth ministry right now. If you're a Christian and you do it, know you're contributing to the sexualisation and dehumanisation of our young people.

Of course, that's not enough. The statistics around Christian porn use are shocking, and shouldn't simply be conceded as another flaw of the modern church, to sit alongside our other untreated issues. If you're struggling with porn use as a Christian, don't shrug; take steps to get help. Pray, find healthy forms of accountability, and distraction techniques that enable you to resist temptation.

While we try to deal with that wider issue though, let's agree this one thing first. While all porn is deeply problematic, I believe some forms hurt us even more than others. So next year, let's pray the world's most requested sex videos don't depict teenagers.

Martin Saunders is a Contributing Editor for Christian Today and the Deputy CEO of Youthscape. You can follow him on Twitter: @martinsaunders