I've just come out of an interesting debate with Alan Rusbridger, the editor of the Guardian, Adam Freeman, the director of the Guardian's commercial department, and Dan Burgess from the communications company Naked.

We were meant to be discussing the role advertising can play in "building a more sustainable future". Of course, what we were really talking about was the extent to which newspapers should restrict the advertisements they carry.

You'll be able to watch the debate here on the Guardian's website when the paper's sustainability review is published next month. But in the meantime, here's what I think.

I believe that advertising is a pox on the planet. It is one of the forces driving us towards destruction, as it creates needs that did not exist before and promotes consumption way beyond sustainable levels. I believe that it is also socially damaging, turning ours into a more grasping, more atomised society, focused on material display rather than solidarity and community action.

I also recognise that it pays my wages. More precisely, that it provides around three-quarters of newspapers' income. Without it, they would not exist: certainly not in their current form, almost certainly not at all. For all their evident faults, newspapers perform a crucial democratic service: without professional reporting, it is impossible to make informed decisions.

Were it not for an industry I detest, I could not be a full-time writer. The Guardian would not be an independent newspaper; the media, even more than it is today, would be a rich man's toy.

Here, it seems to me, are our choices. We could:

1. Keep receiving income from adverts, sustaining the power and wealth of the corporations that place them.

2. Rely on the beneficence of rich men and women to sponsor the newspapers, boosting the power of the proprietorial class.

3. Go to the state.

I find all three options repulsive. Newspapers sponsored by billionaire proprietors (you have to be a billionaire to sustain one) tend to be governed by the demands of that class. Owners interfere far more often and more systematically in the content of papers than advertisers. Their newspapers routinely represent the needs and desires of billionaires as if they were the needs and desires of everyone else, presenting a distorted picture of the world. State sponsorship is just as hazardous, as anyone who has lived in a country whose government owns the papers knows. It's not as if the government is offering, anyway.

In any case, it looks as if we are stuck with the advertising model. The Guardian's journalism costs much more than the price readers pay for the paper. Online articles – like this one – cost you nothing at all. They are, in effect, wholly sponsored by advertising. If we changed that, how many of you would pay?

But what are the costs of living off the dream merchants?

I have never been asked by the Guardian to tone down my attacks on corporations, nor have I come across any evidence that advertisers can influence editorial decisions on this paper (if anyone has any, I would like to see it). During our discussion, Rusbridger explained that he never tries to interfere in the advertising department's decisions, and that this department never tries to sway his decisions. During the Guardian's shocking series on tax avoidance, for example, it exposed some of its own biggest advertisers, as well as the agency (WPP) which places about half of its ads. It has lived to tell the tale.

So this is not what worries me. I am much more concerned about the false picture of the world conveyed by advertisements the newspapers carry. They generate behavioural norms, telling us, in effect, that the goods and services which are destroying the biosphere are acceptable, even beneficial. I believe that their presence in the newspapers makes hypocrites of all those of us who write for them. Our editorials urge people to reduce their impacts. Our advertisements urge people to increase them.

When I have challenged newspaper editors on this issue, they tend to say two things: first that the readers are mostly grown-ups and should be treated as such. It is patronising and offensive to free speech to decide on their behalf which adverts they should and shouldn't see. They should be allowed to make their own decisions. Secondly, dropping advertisements would be economic suicide, especially in the current climate, when the recession has cut total spending at the same time as advertisers are leaving print in favour of the internet.

But advertising is not neutral copy. Its purpose is to influence the way people think and act. It has a clear editorial line: encouraging people to increase their consumption. In all other parts of our newspapers, we retain editorial control. The Guardian doesn't allow Richard Desmond to write its leaders. The Telegraph doesn't hand over several pages a day to the Labour party. When it comes to advertising we wash our hands of it. We say it should be left to the market and we cannot seek to influence people's opinions. We allow companies to make biased, unchallenged statements of opinion – as long as they pay.

But even the claim that we should leave people to make their own decisions is inconsistent and hypocritical. Where are the ads for pornography in these papers? Where are the ads using violent or sexually explicit images? People working for these newspapers decide which advertisements are acceptable and which are not. The Guardian, for example, took a major economic hit when in 2003 it decided not to carry ads for adult chat lines.

We are making decisions on our readers' behalf and deciding that there are certain points of view they shouldn't be exposed to, or certain activities in which they shouldn't be encouraged to engage. The decision to accept advertising by companies causing environmental damage is not an entirely passive one. We have decided that it should pass through the filters which screen out other kinds of ads.

On the second point, I am not calling on the newspapers to stop taking advertising. I can't, because I haven't found an acceptable alternative. I have never been in doubt, uncomfortable as I find it, that advertising pays for my work here, and for everything else that goes into the paper. It's an unpleasant but apparently inescapable fact of life.

What I am asking is for the newspapers to refine their view of which advertisements are and are not acceptable. Specifically, I am calling on them in the first instance to drop ads for cars which produce more than 150g of CO2/km, and to drop direct advertising for flights, on the grounds that both these products cause unequivocal and unnecessary harm to the environment. During the debate, I asked Adam Freeman whether he could find out how much revenue would be lost if the Guardian accepted this proposal.

What do you think? Are there alternatives? Is there something I have missed? What policy should the Guardian and other newspapers adopt?

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